Energy use and GHGs (Green House Gasses) can be broken down into roughly three areas:
Low or mid efficiency furnaces suffer from the energy wasted during startup and cooldown. For our high-eff gas furnace a total of 10% of the energy used by the furnace is electricity. The furnace combustion motor runs for 1 minute while the heat exchanger warms up - before the blower motor turns on and puts heat into the home. Then 2 minutes after the combustion has stoped the blower motor continues to run to remove the last heat from the heat exchanger. This is a signif. amount of electrical use!
Our low efficiency furnace would turn on and run for several minutes before the blower motor turned on and as a result much of the heat went straight up the vent stack. To deal with this I modified the thermostat by putting a thin insulator around the thermister in the thermostat, then wraping that with copper and then adding a chunk of foam insulation. This had the effect of making the furnace run longer each time it came one - increasing the temperature swing in the home. The efficiency of the furnace was around 55% when it was coming on infrequently (shoulder months of winter) and 72% when it was running for long periods during the heart of winter (less than -10C outside).
In Jan 2013 I undid the modification to the thermostat and measured the effect on the runtime of our high efficiency furance. The furnace combustion motor turns on 1 minute before the blower motor and the blower motor runs for 2 minutes after combustion has stoped.
Modified thermostat runtime: 14:00, 15:50, 14:33, 14:35, 15:30, 15:00, 15:50, 14:00 (average 14:50 or 14.8 minutes)
regular thermostat runtime: 12:50, 12:30, 12:30, 13:15, 13:05 (average 12:50 or 12.8 minutes).
Many homes have uninsulated concrete slabs. Insulate from the outside or put down insulation when re-covering the floor. We put down 1" of foam insulation covered by 3/4" of plywood to deal with a concrete slab that went down to the freezing point in the winter.
Converting a chest freezer or upright freezer to a fridge will cut the energy use for refigeration by 60%. A $35 thermostat can convert a freezer to a fridge and save you $50 per year
Get the smallest you can and insulate it. Most imporant is your lifestyle. Making a habit of only using hot water for showering and dishes can cut your hot water use in half.
We've put our electric 19 gallon water heater onto a timer to reduced peak electricity use. Do not use plug-in timers they will destroy themselves. Only use wired-in timers!
Induction cookers are 30% more efficient than standard electric elements and 60% more efficient than radiant stove tops and 2x as efficient at a microwave oven at heating.
Stainless steel (or any shiny unpainted metal) pots and pans take 1/3 less energy to keep hot. They loose heat more slowly.
My testing of stainless pots vs painted pots and how they loose (radiate) a lot less (aprox 30%) heat falls in line with low-e windows (a thin metal film on the glass) being 50% more efficient at keeping heat in.
The best place in a home to put such a "radiant barrier" is in the attic - stapled to the underside of the ceiling - where it isn't physically touching anything and will stay clean. This will prevent much of the summer heat from being radiated thru the insulation and into the home.
US prices indicate 15c/sq-ft for plastic foil and 20c/sq-ft for 2 layers of aluminum foil laminated to a durable core.
The NRCAN article says that for Canadian sites it's more cost efficient to add insulation first and it gets into multiple radiant barriers.
One option is to get a co-generation unit. They get great efficiency by generating electricity and using the heat to heat water for water or space heating. One by ECR called Freewatt has been involved in studies back in 2007 (PDF). It's a natural gas burning ICE engine which is integrated to a heat exchanger for home heating. It appears to be about $25k (including an ECM blower fan ...).
The Freewatt unit consumes 18,450 BTU/hr and generates 12,500 BTU/hr in heat and 1.2kW in electricity. The unit itself confumes 85W of electricity.
As such it seems to be a very nice unit for off-grid living to generate electricity to charage a battery bank and also provide heating. The cost is exceptionally high though. I've heard of people using a regular generator and then piping the exhaust gasses thru a concrete slab for heating and also running replacing the radiator with more in-floor tubing to provide space heating.
This is a comparison of how much energy it takes to bake things different ways.
|Appliance||Energy Use||Wh/min to maintain||Comments|
|Oven||1.5kWh||27Wh/min average||350F, bake 45 min, warm up 10 min for 55 min total|
|Proctor Silex bread maker||0.37kWh||aprox 9Wh/min baking||bake 2lb loaf, took 4h 7min|
|Westend 74706 large Toaster-Table Oven||0.57kWh||8.4Wh/min holding||350F, 60 min. total (10:12 to warmup)|
|Black and Decker Toaster Oven||0.28kWh||6Wh/min holding||350F, 41 min. total|
|Bravetti Toaster Oven TO158BL||0.55kWh||7.1Wh/min holding||350F, 64 min. total|
Black and Decker Toaster Oven 11" wide by 7.5" deep by 3" high.
|Black and Decker Toaster Oven Energy Test|
|Toaster Oven time|
heating element was on
|Energy Use |
for the period
|11||4:22||0.10||8.3||door was slightly ajar|
Note: The Westbend 74706 Countertop oven draws 21W when the oven is on and the element is off! It sounds like this may be due to a fan. The oven draws 1040W with the bottom element on (baking) and 1475W when both top and bottom elements are on.
The oven cooking volume is 12" x 11" x 5.5" and the whole volume being heated is 12" x 12" x 9".
|Westbend 74706 Countertop Oven Energy Test|
|Energy Use |
for the period
Black and Decker "Dining In" Countertop Convection Oven. This unit draws 20W with the fan on, 1405W with both top and bottom elements on. It is 14" wide, 4.5" high and 9" deep.
|Black and Decker "Dining In" Countertop Oven Energy Test|
|Energy Use |
for the period
Bravetti Toaster Oven TO158BL
1300W toasting 6 slices (on one side) takes 5:00 and 100Wh
|Bravetti 6-slice Toaster Oven Energy Test|
|Energy Use |
for the period
|1:04||0.55||7.1||Oven coils on for 35:58|
Oct 2012 - Our Kenmore Elite induction cooker has been repaired by buying two IGBT's (600V, 25A) from Hong Kong (there are several EBay sources but all in China and local suppliers have minimum orders of qty 30+). I also had to replace a bridge rectifier (25A, 1000V) with a similar model (35A, 1000V). Along the way I accidently wired the highest power output to the smallest element and boy it heated things up quickly!
Sept 2012 - Our 7 year old Kenmore Elite induction cooker failed while canning on the large element. The primary circuit board called "filter" has a section laid out for two 20A fuses for the 240V mains. Instead of putting fuses it they used circuit traces to act as fuses.
When the 2 IGBTs and rectifier on the heatsink shorted on a "power" board the trace on the filter board blew causing some slight damamge to an inductor next to it. Thankfully after pulling the failed parts and shorting the vapourized trace it powered up and has been working normally with the left two elements.
The damaged rectifier (GBJ2510 1000V 25A) is readily available for $2 via large local suppliers. The IGBTs (IXGR32N60CD1 600V, 25A) can only be ordered in batches of 30+ locally (aprox $11 ea); but are available singly from Hong Kong or mainland China ($3 to $5 ea).
Some searching will reveal that induction heaters work not only for steel but for aluminum and all other metals - but efficiency is lower than steel.
Induction heaters have been used in industry for quite a while - search YouTube for forges a annealing steel. A 30kVA induction heater at Instructables.com http://www.instructables.com/id/30-kVA-Induction-Heater/ There are some negative comments about the design on other sites - it isn't 30kVA as only 12kVA is available (50A, 240V) but it shows what can be done.
I always wondered how much energy, while canning - keeping a liquid at a boil - how much energy is lost due to radiation. Shiny metal pots radiate about 1/10 the amount of heat of a painted pot. However, heat is also lost by convection (air carrying the heat away) and conduction (whatever is touching the pot).
Summary A shiny bare metal pot will take about 1/3 less energy to keep at a boil than a coated metal pot.
In this experiment I had 2 similar pots:
NOTE: In one test I failed to quantify the energy required to keep a light boil! I used the induction cooker temperature setting (regulation) to keep the pot at a constant temperature. The measure temperature the cooker uses a thermister pressed against the middle of the glass top. The one stainless pot was recessed in the middle so that the temperature setting which worked with the black pot kept the stainless pot at a full power and a constant rolling boil! Reducing the temperature by one notch, with the stainless pot, resulted in no boil at all and the induction cooker off for minutes at a time - so it was not a valid comparison.
Note: Pot temperature is measured with a Fluke IR temperature probe - it basically measures the amount of heat radiated and is inaccurate for the stainless pot - but it is a measure of radiated heat so it's interesting to note.
Note: The measurements are about 14% accurate. Going from 0.25 kWh to 0.32 kWh is only accurate to 1 part in 7 or about 14%. Running the test for an hour, and measuring the amount of water left (correct for how much was evaporated) would increase the accuracy by 6-fold.
Note: The energy to boil water in real world measurements includes energy put into the water but then lost the the environment. As the most efficient way to heat water requires 2.5x more energy than that actually required; one must assume that a signif. fraction of the heat put in is lost to the environment.
|Energy Use |
|No Pot |
|-||0.092||-||1L (1 kg) of water raised 80C|
|Black steel||0||0.0||20.3C||starting 2L of water, Iwatani cooker 1450W|
|11:10||0.26||112C||pot at boil|
|13:00||0.28||109C||cooker 8W when resting, 200F light boil, 250F rolling boil|
|23:00||0.36||-||80Wh per 10 min. alternating between light boil and simmer|
|Stainless steel |
Bad Pot Design
Temp. regulation fails
|0||0.0||20C||starting 2L of water|
|10:21||0.25||38C, lid 103C||boiling|
|13:00||0.28||C||200F setting draws 909W keeps a rolling boil, tried 170F but stayed below a boil|
|15:00||0.29||C||tried 200F setting, hard boil for 2 min., did not stop|
|17:00||0.32||C||Power setting 3, constant light boil, 530W power draw = 88Wh per 10 min|
|Smaller Stainless steel||0||0.0||20.3C||starting 2L of water|
|10:30||0.25||36C, lid 97C||boiling|
|12:00||0.25||37.1C, lid 102C||set to 250F, alternating 905W and 8W|
|25:00||0.32||37.4C, lid 106C||54Wh per 10 min, alternating between good boil and simmer, 33% less energy than the black pot!|
Our first impression was very positive. The 1500W Iwatani heated a cast iron frying pan faster than our 2.4kW electric element and cooking was cooler (for us) and faster. Boiling over pasta resulted in no burning as nothing was hot enough to burn the starch.
The Frigidaire GFGI13P3KS (available thru Sears) is only about 1200W and works well at low power levels. It has no temperature control.
The STOP restraunt supply store sells the EuroDib single for about $170 (rated 1800W but likely more like 1600W) and the EuroDib Commercial (stainless case like the Iwatani) for about $410.
The Max Burton 6530 ProChef 3000W looks nice (search www.Amazon.com) but at least one review points out that it's low power settings are very poor - cycling high power on and off and burning everything but water.
The BergHOFF is rated 260 to 1600W while the Iwatani is rated 1500W but the bottom sticker says 1440W. Standard electric ranges are typically 1250W for small elements and 2500W for larger elements. The BergHOFF works very poorly at low power levels - alternating between full power rapid boiling and turning off - unsuitable for heating milk, cooking rice, melting chocolate or re-heating thick soups. In comparison the 2 lowest power settings on the Iwatani are lower power than the lowest setting on the BergHOFF. The lowest Berghoff is unusable for cooking rice - keeping the contents boiling and venting steam.
These measuresments were done with a Yokogawa 2343 400/1000A clamp-on ammeter which has a resolution of 100mA and an LEM PR 30 clamp-on current problem which connects to an oscilloscope and gives 100mV per A.
|Induction Model||Standby Power Draw |
|Calculated Power |
Real + Reactive
|Kemore regular stove 2005||5mVp-p (50mAp-p, 35 mArms) |
(current is roughly sinusoidal)
|Kemore Elite Induction 2007||3 mVp-p + 9mVp-p spikes (display off) |
4mVp-p + 15 mVp-p spikes when on in standby
(current is triangular with spikes)
|<15W (15W if 9mVp-p sinusoid)|
<36W (36W for 15mVp-p sinusoid)
|BergHoff Earthchef|| 167mVp-p, 36mVrms |
Fan On: 177mVp-p, 37mVrms
(current is triangular)
|43W (reactive, not real!)||38W|
|Iwatini 1500||0.85A, 290mVp-p () |
(current is triangular)
|102W (by 0.85A) |
25W (by 290mVp-p)
|9 to 15W|
|Kenmore Elite Induction Cooktop|
|Element (inches)||Power Level "P" |
|Power Level 9|
|6"||7.4A (1.8 kW)||5.7A ( 1.4 kW)|
|7"||9.3A (2.2 kW)||6.15A (1.5 kW)|
|8"||10.4A (2.5 kW)||6.1A (1.5 kW)|
|10"||13.7A (3.3 kW)||9.5A (2.3 kW)|
|Induction Model||Standby Power Draw||Max Power|
|Frigidaire GFGI13P3KS||4 to 12W||1150W|
|Iwatani 1500||9 to 15W||1480W|
|BergHOFF Earthchef 1810003 |
Two units tested.
|38W off, 41W on||1529W|
|Electricity use for cooking||40W average estimated||100W gov. estimates|
From the above table it's clear that the standby / vampire energy draw of the BergHOFF is
exceptionally high - it uses as much energy when off as my family uses cooking!
One should not get an induction cooker to save money as it will not be much. For my family perhaps $7/year. If one is living off-grid though, the reduced power draw is worth it.
This table tests how long it takes to bring water from 20C to 99C (boiling). The time measurements are +/- 6 seconds. The pot is a 1.2L capacity, 5" diameter (flat) bottom weighing 450g about 400g without the handle. The same pot was used on the electric and induction ranges. Note that the electric range element was 5.75" diameter so the outer ring was not touching the pot - it was glowing a dull red.
To calculate the energy to boil 1L of water (20C to 99C):
1 BTU raises 1lb of water 1F. 16,600 BTU ~ 4.9kWh, 1 US gal = 3.79l = 8.3LB. 1L = 2.19lb, 20C = 68F 2.19lb * (210 - 68F) = 311BTU => 0.092 kWh = 92 WH
Energy to raise 1L of water from 20C to 99C water done with other units:
specific heat 4.16 kJ/kg * degree, 3600 kJ/kWh
1L = 1kg, temp difference = 99C - 20 C = 79C
4.61 kJ / kg * 1kg * 79C / 3600 kJ/kWh = 91.3 Wh
|Cooking Method||Time to boil 1L water||Power Used for 1L |
EM100 Energy Meter
|Power Used for 1L |
Home Elec. Monitor
|Energy Saving (over elec. range)|
|Electric Kettle||5:03||1400W |
|Iwatani Induction range||5:09||1466W |
|BergHOFF Induction range||5:06||1490W |
|Flat-top ceramic or radiant electric range |
450g steel pot
|9:45||est. 1400W |
|Electric range |
450g steel pot
|Electric range |
600g Aluminum bottomed pot that nearly covers all elements
|Electric range |
2L of water in Large pot (1.2kg)
that nearly covers large 2.5kW element
ENVI home monitoring had data logging issues
|Sanyo EM-S250 microwave |
0.5L of water in 600g cup
|5:03||1450 to 1360W |
|25 year old microwave |
0.5L of water in 600g cup
|10 year old microwave |
0.5L of water raised 18C in 1 min using 0.03kWh
|8 min||0.240Wh||N.A.||Initial data not very accurate|
Actual data. 25 year old microwave heated 0.5L of water from 20C to 86C with 0.09kWh at 1350W.
The Sanyo EM-S250 took 4:30 to heat 500mL of water from 21.5C to 92C using 0.10 kWh. Power draw started at 1450W but decreased to 1360W at the end.
Note that microwave ovens have big, noisy cooling fans because the magnetron which creates the microwaves is really only about 65% efficient.
Bill Kemp in the 2009 edition of The Renewable Energy Handbook mentions induction cooking. Info can be found:
IKEA has a $1,000 4-element drop-in induction range and all of their cookware (including pressure cookers) are induction compatible.
CostCo and Sears have a $99 single burner model. We purchased a used IWatani 1500W model. It was a from a restraunt and well greased. One resistor had failed and only the grease around it and a transitor kept things working. A capacitor was also puffing and on it's wait to failure. The cooling fan blows dust and oil into the one side of the controls and that caused the problem.Our existing stove has 1.8kW and 2.4kW elements. The 2400W one is needed for canning and it would be great to have an induction cooker near that power level as during canning the range gets very hot and the elements are glowing red hot. That makes me doubt that we meet the criteria used by the DOE which placed induction cooking at 84% efficient while a standard electric range was 71% (and natural gas is 40%).
Aug 28, 2010 - our Woods fridge has a failing thermostat (replace last 1.5 years ago) and replacement thermostats are not available. Here are some options:
Family has a near "passive house" with triple glazed windows and excellent detailing to deal with air leakage. Issues include:
Continously running the furnace fan is not an option - way too high power draw and we don't want the house all the same temperature.
Fresh air in via a 20' pipe from basement corner thru garage to outside
Must try to use solid metal pipes - not flex pipes for such a long run.
Suck from bathrooms
Blow to master bedroom, lower living room
air heat loss = cfm * 60 * 24 * 70F * 0.02BTU/cu-ft = 100,000 BTU/day = $30/mo, HRV eff is aprox 60% - saving $18/mo, Fantec model is aprox $3.50/mo to operate.
A Canadian Tire / Xantrex non-sine 700W inverter would indicate a fault the moment it was connected to the home wiring. It seems that it can't handle long wires. However, it could start the fridge or freezer if connected directly to them.
APC 350VA UPS appears to be non-sinusoidal. It did not shut down when connected to the home wiring; however it didn't have enough capacitity to start the fridge compressor.
This is a measurement of the temperature of the raised, uninsulated, concrete slab of our livingroom (back half of a backsplit home). In the winter the slab gets to the freezing point close to the edge. We pulled up the carpet and put down 1.5" of foam and covered that with 3/4" of plywood and bamboo and the floor feels warmer than carpet on a cold slab.
|Date||Ambient (C) |
0C outside, 17C inside at 6am, 14.7C at the carpet by the patio door, 11.2C under the carpet.
I was wondering if my attic had adequate ventilation. It seemed hot up there so I did some measurements.
According to some information I found an unvented attic will hit 150F or 65C and that a well ventilated one should peak around 95F or 35C. That seems unreasonable since the ambient temperature will easily hit 35C on a hot summer day.
Clearly there was enough ventilation for the attic to drop to ambient overnight.
|Sept 16||12pm||cloudy all day||27||25.3||30.1|
|Sept 20||5pm||sunny day||24||23.4||35.7|
|Nov 16||4pm||snow covered roof||-3||16.3||0.5|
|Nov 21||3:30pm||snow covered roof||-5||15.3||0.3|
As we're on the north side of a semi-detached we have no south facing anything.
I setup a 30x30" mirror on our deck to shine sunlight thru our patio door. It adds
an amazing amount of light when the sun is shining.
10:20am Feb 20, 2010 - the deck is illuminated by sunlight
10:30am weak (cool) light comes into the living room
2:00pm the house shades the deck, and mirror (before this the light was strong)
With time of day electric pricing we're considering ways that this can save us money.
Here is a comparison of electical prices:
|pre ToD cost||5.8c|
|ToD average||6.21c (7% increase)|
|ToD day/evening||7.45c (29% increase)|
Summary: Things that are on 24x7 (fridge, freezer, clocks, vampires) will increase
7% in their cost of operation.
Things which are done during normal waking hours (cooking, lighting, entertainment, heating) will be 29% more expensive to operate under ToD pricing.
I'm not very happy with the way we're implementing it in Ontario. This is not a revenue neutral scheme - prices are going up. Price increases will help curb demand; but it could be done better. Why not nail people who use lots of electricity - basically go after the ones with A/C units
What Can I Do? We've put our 19 gallon water heater onto a timer (electric, 7-day programmable - 2W power draw) and set it to only turn on for 1 hour before the price rise in the morning. This provides mostly enough heat (only a bath requires it to be turned on otherwise). If necessary it can be boosted by turning it on for 30 minutes during a mid-peak time period.
March 1, 2010 Water Heater Timer Energy Summary
Here is the summary of having our water heater on, and off, a timer. Note that a steady 2W power draw is from the timer.
Estimated daily losses (standby 0.6kWh, shower 0.2 and 0.6 kWh, dishes 0.15 kWh, laundry 0.3 kWh, bath 1.2 kWh).
30 days on a timer 1.19kWh/day average actual use, 1.29 kWh/day calculated average (-7.4%)
12 days w/o timer 1.45kWh/day average actual use, 1.16 kWh/day calculated average (+12.4%)
Summary: The timer saves us 20% of our energy use. Also - with the timer 30% to 50% of the losses were standby indicating a need for better insulation.
The washer (front loading) doesn't use much electricity. When the drier is used (winter) it should be used during non-peak periods. We only do a load of laundry a week and it's on the weekend.
Baking tends to be done on the weekend at reduced rates.
Frankly - this will be a big cost increase as consumers can't really shift their electrical use to out of demand times. Those who are use electrical heating and set back the heat at night - will be doubly nailed.
Furnace Setup We setup our temperature at night and I thought about ramping the temperature up before electrical prices jump. However, we spend about $2.75/day in gas for heating and 15c/day running the furnace (750W draw, running about 2.75h per day. Our furnace uses about 2.75kWh/day and the water heater uses about 1.5kWh/day.
Trying to shift the energy use of a fridge or freezer isn't really an option. Many spend about 30 minutes out of every hour running. If one were to try it - then a freezer is the easiest to start with as they can handle a larger temperature swing.
Our black beast from hell (tm) Ford Escort has a failing transmission. Cars basically come in three
Echo, Fit, Yaris (Corolla??) around 7.0 / 5.5 L/100km
Civic, Vibe/Matrix around 7.9, 5.8 L/100km
Aveo, Sentra, Accent around 8.5, 6.2 L/100km
How does the choice of car change our emissions. We are currently about 1,900 kg/yr CO2 for 10,000km with our Escort at 34 mpg. Upgrading to an Aveo would save about 380kg/yr CO2. Upgraing from Aveo to Yaris would save an extra 250 kg/yr CO2 for about an extra $2k in the purchase cost.
Upgrading things at home though:
fridge ($700, 50 kg/yr CO2, $7/yr elec. savings)
freezer (so that I can convert it to a chest fridge!!!!) ($700, 50 kg/yr CO2, $7/yr elec. savings)
patio door ($600, - current guess 150 kg/yr CO2, $20/yr heating savings)
insulate exterior wall or living room floor $700??, save 150kg/yr??
Yea - this is a far out there scheme as our insurance agent doesn't know a company that'll touch an EV conversion. This place has great info: Wilderness Electric Vehicles
[This upgrade was done summer 2010] The patio door is aluminum frame - and 2 doors thick, each with a single pane of glass. A modern vinyl door should increase this from R1.5 to R3 for about $500 with a savings of about $20 in heating per winter.
[This upgrade was done summer 2010 1" R5 foam] The lower living room (home is a back-split) is an UNINSULATED concrete slab above grade. This means that it's around 7C within 1yd/meter of the wall in the winter and 16C in the middle of the home.
The plan is to put 1.5" of foam down and cover it with 5/8" TG board and replace the carpet.
The estimated cost is about $800 (for 400 sq-ft) for foam, plywood and screws. I'm assuming I can re-use the baseboard and carpet tack.
The snags will be that at the bathroom and patio door - the insulated floor will be about 2" higher now. If I replace the patio door at the same time I can raise it perhaps 1/2 to 3/4". The difference at the stairs (up and down) shouldn't be too bad. There are no heating ducks or anything in the slab.
[Aug 2010]. We leave an R5 1" foam sheet over the chest freezer. It has allowed me to calculate that the chest freezer door is R19. 19.5C ambient, 11.5C under 1" R5 foam, -19.2C inside freezer (metered with an IR thermometer - inside freezer is -17.6C based upon thermister).
In our home we use the freezer to store fruits for the winter (deserts and sweeten oatmeal) as well as store bulk food purchases and "emergency" foods (quick suppers if we get home late).
One idea is to pitch the fridge and use a small, well insulated box to keep what few things need to be refigerated - using water frozen in the freezer. In our case there is little stored in the fridge (fruits, veggies, salads - which could be kept cool in a cold cellar - if we had one). We use soy milk (insurance in terms of vitamins and minerals for the kids) - but that could be bought more frequently. Savings would be about $40/yr or about $0.80/wk. Is that worth having to shop more frequently and shuffle frozen ice between the freezer and a small fridge box?
Feb 23, 2009: I started by taking two 2L pop bottles. While one is freezing outside, another (frozen) one is in the fridge. So freeze them for free outside and let them keep the fridge cool.
Summary: While this might be a way to reduce operating costs it doesn't work well at all. It takes a long time for the ice to transfer it's cold to the fridge - one would need more surface area than pop bottles allow. Also freezing the bottles outside took too long.
Crunching some numbers - ice is 80 calories / gram to freeze and 1 cal/gram otherwise to change the temperature. So taking ice from -5C to +5C will take 10 cal/gram for the temperature change and 80 cal/gram for the phase change. Clearly the phase change is important!
Basic calculations. Assume 1.8L per 2L bottle, heat absorbed is due to phase change (80 cal/gm), that is 144 k-cal. Our fridge uses 1kWh/day (1 BTU= 252 cal, 1Wh = 3.4 BTU) or 857 k-cal/day. So each 2L bottle could provide about 8% of the cold if it melted over 2 days.
The data was not very clear with 1 or 2 water bottles. It appears as if there were some energy savings (about 10% per bottle) over the first 12 hours (power was measured at 12 and 24 hours) but not a signif amount during the next 12 hours. The bottles took about 2 days to melt fully. Frozen bottles from the freezer (-20C) worked better than ones marginally frozen (perhaps -4C) in the garage. It took at least 2 days to freeze a 2L bottle in the garage.
November 2011 - The best bath fan I've found so far is a Panasonic Whisper Green which is rated at 12W and 80cfm.
November 2009 - We've bought a Broan 70cfm 0.8 sone bath fan and found it exceptionally quiet UNTIL it was connected to the 3" plastic exhaust pipe. A 4" metal exhaust pipe was much quieter but still about 2x as loud as the fan without a pipe. We highly recommend using a minimum of 5" metal exhaust pipe with ideally no bends to allow the fan to be as quiet as possible. The 29W power draw means that the cost of operating this fan over the winter will be $7.50 + the cost of re-heating cold air brought into the home. Fresh cold air is brought in via a bedroom window left open about 5mm.
Note: July 2009 - We've decided to modify a bathroom fan to use a low CFM fan in order to suck air out of the house (from that room and possibly others) and then fresh air is introduced via a window or air intake in the bedroom. I'm toying with using 5" computer fans as they're quite, low power and free.
Here is a site with some great numbers: CEERE.org IAC
Jan 2010 Update
After having day after day of ice flowing from the patio door into the carpet and windows being frozen shut we did some tests.
Jan 5, 2010 - R5 insulation on windows, over night, results in light frosting underneath Jan 4, 2010 - 36% RH, outside -15C (minor ice on windows) Dec 5, 2009 - 50% to 51% RH - the lower the outside temp the lower the humidity Nov 2009 - 56% to 60% RH Oct 2009 - 54% to 63% RH As of Oct 2009 we use our bath fan (70 cfm) left on overnight, in combination with a bedroom window left slightly ajar - as a way to ventilate the home Jan 15, 2009 - work is 70F 21% RH, outside -15C - our home is 40% RH at 19C - the kitchen was 48% RH when making pasta Jan 16, 2009 - 14C, 40% RH at 6am - 5pm 18C 37% RH, outside 3F 84% - Honeywell meter says 18C 38% RH, RadioShack meter says 61F 45% - in the shower is was >63% RH at 20C Jan 18, 2009 - 7am 40% RH, 15C, a door and window was opened then at 8:30am it was 19C 39% RH Neighbour #1 home 17C, 30% RH (one occupant, no condensation on windows) Neighbour #2 home 25C, 45% RH dish washer just ran (family of 4, condensation on upstairs windows) Jan 19, 2009 - 6am 41% RH (43% other meter) at 15C Jan 20, 2009 - two windows opened about 1cm 34% (35% other meter) 19C Jan 21, 2009 - 5am 59F 37% RH (in an old building it's < 20% RH)
We have very little condensation on windows now with it -10C outside and 37% RH inside.
I've been thinking of a HRV to deal with humidity issues during cold snaps. The Venmar 2600 for $850 is readily available and uses a washable filter - so no consumables. It is rated at 50 to 100 cfm while drawing 120 to 190W. Given: 1W = 3.413 BTU/h, a 30C or 54F temperature difference between outside and inside (20C vs -10C), Air at 1 ATM is aprox 0.07 lb/ft^3, Cp (specific heat) of air is 0.24 BTU/lb F I get:
120W is 410 BTU/h
50cfm, at 54F difference is 2.7k BTU/h. The Venmar is apparently 60% or 80% efficient at heat transfer. That makes the air exhange loss at 1.1 kBTU/h (60% efficient) to 540 BTU/h (80% eff). NOTE: That at 120W continuous draw this HRV would increase out home electricity use by aprox 30% (We are 8kWh/day typical winter use or 333W average draw)!
The upshot is that (at $0.10/kWh) it would cost $25/yr to run the HRV for 3 months (all day and night), and the cost for re-heating the air would be (at 60% HRV efficiency) very very roughly $50/winter. But home heating costs are $350/winter - so it's a lot easier to just open the windows during cold snaps.
Our home is rated (REEP evaluation) at 5.3 ACH and 4.9ACH after a furnace upgrade (removed 6" air intake) but not the B-Vent as it was still used by the gas fired water heater (since removed, vent pluggeg). By the REEP calculations that ment 0.17ACH for a typical October in the area.
http://www.niagarafalls.ca/city_hall/departments/municipal_works/water_meter_faq.asp - City of Niagara Falls Water Meter FAQ. Summary: the average PERSON uses 9 cubic-meters of water per month!
Average Electricity use is http://cesenet.org/documents/canada.pdf 1070kWh/mo for Canada. We are around 270kWh/mo in the winter and 180 kWh/mo in the summer.
As of July 2008:
Using a pail with sawdust to urinate in. Read "The Humanure Handbook" and "Liquid Gold". Sawdust controls the odor very well. By using the moto "If it's brown flush it down - if it's yellow, let it mellow" can save a lot of water. So - by using a urine bucket, our family of 4 can save around 3 flushes / day or about 12L. Water/sewage costs $2.60 per cubic-meter - so our savings are around 0.30 m^3/mo or around $0.80. About a 1 gallon pail of sawdust is used daily, and sawdust locally is $10/cubic-yard so I'm betting that it'll cost us around $10/month to do this! But you get great compost. Our compost pile runs good and hot with urine added to it.
I'm looking at numbers for solar water heaters. We use around 70W average for our electric water heater - that's around 5,000 BTU/day of heat. A Vissmann flat plate collector system (2 collectors, water tank and all parts) is around $7k and will, on a warm winter day deliver 10,000 BTU of water at 50C (fully cloudy day, -10C outside, 40C water). This could possibly be used for space heating - if we put in radiant floor heat. The system peaks at around 40,000 BTU/day on clear days over 0C. Our home takes around 150,000 BTU/day on a typical winter day of -10C. If we could direct the hot water to space heating - then such a system would help with the shoulder months of the heating season (Mar, Apr, May, Sep, Oct).
As of June 2008:
If we had a cold cellar we could reduce the size of our fridge - but "bar" fridges are the only smaller model - and they use the same out of energy. By changing how we eat it's concievable that we could do without a freezer (use more canning and food drying and making things fresh) or more radical still go without a fridge and freezer (ala the Mennonites).
We could upgrade to a slightly smaller freezer (ours is 12 cu-ft (rated 351kWh/yr) and only the 10 (rated 282kWh/yr) and 15 (rated 354 kWh/yr) cu-ft models are Energy Star rated) or a newer fridge (ours is rated 18 cu-ft 432kWh/yr; while new models are 18 cu-ft 358kWh/yr, 11 cut-ft 388 kWh/yr) to save 70kWh/yr EACH. So a cash layout of about $800 each to save $8/yr
We could re-locate the freezer and fridge seasonally! This would mean moving the freezer into the garage during colder months - electricity use would be nearly 0 in the winter. The fridge would alternate between the kitchen and basement - for an aprox 20% savings in the summer (basement stays around 20C while the upstairs will exceed 30C).
It would be nice if there was a way to make use of the waste heat from the freezer or fridge compressor - they are around 30W/yr each and our water heater uses 70W average. But such schemes would be complex and quite awkward for small savings. Well - the potential savings exceed that of the 8W average savings that a fridge or freezer upgrade would give us.
A plastic bag to heat water (camping "shower" bag) saves about $0.02 per shower (during a normal shower it takes 1.5L to purge cold water + 1.5L hot + 1.5L cold). The shower bag cost $12 and we also use it to make warm water for washing dishes. So the payback is 300 uses or 60 weeks - or about 4 years of summer use. I doubt that it'll last that long; but a friend reported 11 summers of use at the cottage before it failed. It is very awkward - hauling the bag around, putting water into it, suspending it in the shower in the home to use it.... We get 39C water (hot to me) and 35C (warm to me) water from it. A plastic water jug in the car will easily get to 35C in a black car on a sunny day.
A hot water tank in the attic would provide hot / warm water during summer without the expense of a solar system on the roof. It would only work in the heat of summer - but could, perhaps, cut our hot water use to 0 for 3 months of summer - saving about $18/yr. The only snag is a where exactly to put it and how to setup a drip can so that WHEN it leaks it will not destroy insulation and lots of drywall!
Perhaps using a pool solar water heater? Enersol 4'x8' collector is $232 + PVC tubing + pump ($175?) + hot water storage tank ($200??) + a check valve, sensor and 3 port valve - perhaps $800 in parts to build a hot water heater. However, a system using a pump is reported to use $10 to $20/yr in electricity and systems have been documented to reduce water heating by 80%. Such a system would only work for about 1/2 (3/4?) of the year and that would imply $15/yr savings - for an outlay of $800 or 53 year simple payback.
Grey water recycling. Water from everything but toilets and kitchen sink, gets filtered and then used for toilet flushing. It apparently costs about $3,600 and saves $200/yr on water (60 m^3 of water per year for a family of 5). For our family that's not possible as we only use 48 m^3/yr for all of our needs - we use about 1.5 m^3/mo for the toilet. Also - we don't use enough water outside of the kitchen for our toilet!
The tossing and turning is finally over. Our 15 year old water heater sprung a leak and we were forced to upgrade. The story and why we went to a 19 gal electric water heater is here. The 19 gallon model uses an average of 2.0kWh/day.
In Jan 2001 I had a REEP home energy evaluation and the home rated 77. That could be raised to 82 with a high efficiency natural gas furnace and a heat exchanger (HRV). In this scale, a home with a rating of 100 has no heating costs while a rating of 0 means that the home is expensive to heat, has cold drafts and/or has poor air quality.
Here are my Electricity Use, Car Pollution Measurements
According to the OEB, 60% of Ontario households use <1,000 kWh per month. We use 6kWh/day or aprox 200 kWh/month.
Energy usage was measured using the watts up? standard power meter from Electronic Educational Devices INC http://www.doubleed.com
The accuracy is listed as a fraction of the measured value: +/-3% +/-2 digits for loads >10W and +/-5% +/-3 digits for loads <10W.
Note: The Watts up? meter is quite inaccurate at lower power readings! I've found -30% error on 10W and 15W readings! At times when the Watts up? meter reports 1W, an alterate meter reports 3W or 4W.
Power Measurement with Hydro Meter An excellent way to measure the power use of some things, and find vampires is to just
use the hydro meter on your house. You need to time how long it takes to do a full, or partial, revolution of the dial.
P = (3600 * dial revolutions * Kh) / revolution_time_seconds
Kh will be indicated on the meter. For low power measurements I typically count how long it takes to do 0.1 or 0.2 of a revolution as that'll be 3 minutes! Note that the meter does become inaccurate at about 15W and less. For low power my meter doesn't seem to turn at all.
Lifestyle makes a big effect on your energy consumption. Not leaving lights on, not automatically turning on the hot water, paying attention to energy use when you purchase things and not living a consumer lifestyle can cut your electricity use in half. We have a gas guzzling car (Ford Escord Wagon) but by not using it unless we have to and using public transit, walking or bicycling we can save more energy than someone buying a hot-rod Prius or other hybrid car and we don't have to spend $30k to do that!!
These measurements were done to quantify how hot the attic was getting and if extra ventilation would be good. Note. This was done AFTER our roof was re-shingled!
Two different thermoemeters were used - a standard alcohol one outside the kitchen window for outside temperature and a digital one (with local and remote temperature readout using a thermister).
|Date||Time||Outside (C)||Inside (C)||Attic (C)|
|July 11, 2006||8:15pm||29||29.9||37.2|
|9am||23||rain much of the day|
These tests were done to see how the concrete slab temperature changes in the winter. The furnace is off all night and runs at about 8am so tests were done well before the furnace ran in the morning.
|Date||Time||Ambient (C)||Location (C)||Location|
|Nov 16, 2006||6am, 19C living room furnace thermostat||21.4||20.8||basement wall behind sink|
|19.8||19.8||basement floor under carpet by water softener|
|19.2||19.6||basement floor by stairs under carpet|
|Nov 18||20.2||19.8||basement floor under carpet by water softener|
|Dec 23||19.5||19.2||basement floor under carpet by water softener|
|furnace exhaust duct||23.0||35.7||basement|
|Dec 20||21.5||19.2||basement floor under carpet by water softener|
|Dec 26||21.6 / 21.8||35.4 / 35.7||basement floor under carpet by water softener|
|Jan 1, 2007||21.0||19.3||9am basement floor under carpet by water softener|
|Jan 2||18.9||18.9||6am basement floor under carpet by water softener??|
|Jan 9||17C ambient living room||18.4||17.4||6am basement floor under carpet by water softener|
|Jan 12||18.9||18.6||basement floor under carpet by water softener|
|Feb 4||17.9||17.8||basement floor under carpet by water softener, it's been -18C outside for days!|
These measurements were done using a Fluke IR thermometer January 22, 2008.
-8C outside, 16.1C inside:
13.9C exterior wall, 13.3C at a stud
basement concrete floor 16.1C (bottom of stairs), 16.9C at the 1/2 wall by furnace, 18.6C shared concrete wall with neighbour, 15.3C under the stairs, 14.7 middle of floor, 16.0C bathroom tile (one floor up)
Windows metering on masking tape on the glass:
5.6C vinyl edge of window, 9.5C center vinyl pillar, 6.5C wood sash, front Oran window vinyl sash 9 to 11.5C,
bay window floor 13.5C to 0C in corners (air infiltration)
Windows 5am, 15.5C inside, -8C outside:
patio door (curtained) 5.4C, low-E living room curtained 7.5C, kitchen double glazed 5.4C, bay TiR window 9.5C, sewing room low-E 7.0C, sewing room failed low-E unit 4.5C
front wall 12C, 8C in corner, 12.6C front steel doors, 11.3C beside door (studs), 9C corner, ceiling 9 to 11C, aluminum patio door 1.1C, curtain covering patio door 11C, curtain covered window sash 4CNov 2007, Outside +2C, inside 18C, low-E glass 14.6C ambient 16.4C, TiR bay window 15.6C ambient 16.6C, kitchen (reg. double glazed) 13.1C ambient 16.0C, patio door (2 single layers of glass) 12.4C ambient 17.1C
Here are upgrades done to our house and their expected benefits:
Here are things which we plan to do:
|Seasonal Increase||Comment and Improvement|
(power draw when on)
|high-eff York GY9 gas furnace elec + fan||13W||69W (5 mo/yr)||fan aprox 260h per winter (7.7A, 740W, pf=0.8)|
DC motor is $1000+ but may not fit!
motor for combustion air is ALWAYS AC!
|Water Heater (19 gal)||20W||50W||-2W summer||2.0kWh/day (83W) average winter at 52C, Use a solar shower bag in summer|
|Fridge||0W||35W||+15W in summer||use increases 33% in 3 months of summer|
|Chest Freezer||0W||46W||+5W in summer||replaced 13 year old with larger, 4 year old chest with same EnerGuide rating, NOTE:use increases aprox 10% in 3 months of summer|
|Range and Oven|
|2W||40W||+20W winter||using toaster oven when possible, replaced old oven with new one rated 900kWh/yr or 103W average|
|P3 Computer (6W), 19" LCD monitor (2W), printer (4W), DSL Modem (7W)||19W||23W||5h / day, 5 switching power supplies (55W, 46W)|
|Clothes Drier||0W||0W||28.5W winter||assume 100 load per year, rated 900kWh/yr or 47W average|
Use clothes line 5 mo/year
|27" TV||5W||10W||assume 2h/day (110W)|
|Living Room lights||6.5W||10.5W winter||8h/day winter, 3h/day summer, upgraded to CF 1999 (50W)|
|Microwave Oven||0W||2W||0W||5W for clock est. +2W heating food (2 min/day), July 2006 rewired so that it's off if door is open|
|VCR, DVD, TV antenna amp||0, 0, 3W||< 1W||0W|
|Central Vac.||0W||1W||1W is for 15 min. use every 2 weeks|
|Dining Room lights||< 1W||8.5W winter||1 hour / day, 6 months winter (200W)|
|Kitchen Room lights||1.75W||1.75W winter||2 hour / day, upgraded to CF lights 1999 (20W)|
|Basement dehumidifier||0W||0W||12W summer||400Wh in 33 hours, 3 months / year|
|Washer||0W||1.5W||assume 100 wash loads per year - rated 196Wh/yr, 22W avg, includes electric heating of water|
Popular Mechanics USA sys washer and drier are 1200 kWh/yr
|Home Stereo equipment||0W||1W||Aprox 15 min. average per day (23W)|
|CD player||0W||<1W||Less than 15 min. per day (4W)|
|CO Detector||4W||8 mo winter||Only plugged in during winter when furnace is on.|
|Garage Door Opener||3W||4 mo winter||Only plugged in during heavy snow in winter.|
|Transformers||2.75, 3W||0W||Answering machine 2.75W, cordless phone 3W|
Replaced transformers with switching power supply
|3 GFI outlets||<<1W||<<1W|
|TOTAL||37W||188W||Winter +72.5W (+20.75W lights) |
|275W avg in 2006 actual use|
|Unplug things||0W||0W||April 2012||cordless phone, answering machine switched off at night|
|Induction cooker (WILD GUESS)||0W||5W||Oct 2011||measured 1/3 less energy use than electric hobs|
|Unplug TV||5W||0W||Oct 2011||On power bar, rarely used now|
|LED LCD||2W||5W||Oct 2011||30W not 46W in use|
|Fridge upgraded to converted freezer||0W||20W||Sept 2010||Uses less in summer too.|
|TV antenna amp||2W||0W||Aug 2008||slight reduction of signal quality|
|Clothes Drier||0W||11W||July 2006||Use clothes line 5 mo/year|
|Washer||0W||0.5W||July 2006||100 loads per year, replaced old top loader with front loader, rated 196Wh/yr or 22W average (includes electric water heating energy)|
|Microwave Oven||5W||0W||July 2006||5W for clock est. +2W heating food (2 min/day), July 16, 2006 rewired so that it's off if the door is open|
|4 Smoke Detectors||20W||0W||2004?||Replaced with battery operated units costing aprox $8 / year in batteries|
|gas furnace upgrade||4W||-12W||Dec 2006||aprox 450W when fan is on|
|low-eff gas furnace elec + fan REMOVED||0W||10.1W||17W (8 mo/yr)||fan aprox 230h per winter (325W)|
|Door bell |
|2, 2W||0W||April 2006||powered from 9V batteries from "used" smoke detectors or unplugged|
|Garage Door Opener||3W||0W||2005||Only plugged in during heavy snow in winter - 4mo/yr.|
|CO Detector||4W||0W||2004?||Only plugged in during winter 8 months when furnace is on - 8mo/yr.|
|Central Vac, VCR||7W, 3W||July 2006||Only plugged in when used.|
|P3 Computer (6W), printer (4W), digi camera (4W)||7W||July 2006||unplugged digi-cam dock, turn off computer power bar at night|
|Computer CRT replaced with LCD||4W + 0.5W||October 2006||Replaced 6.5 year old 17" CRT (65W) with Acer 19" 1951 LCD(46W), enabled suspend mode after 20 min (copmuter reduced to 33W)|
|Transformer upgrade||3W est.||0W||June 2006||Save 3W, Replaced answering machine & cordless phone transformers with switching power supply|
|Water Softener||6W||0W||July 2006||unplugged and we manually trigger regeneration every 6 weeks|
|Answering Machine||4W||0W||May 2006||C60 tape Answering machine 7W replaced with microcassette model with switching power supply upgrading transformer blob|
|Lighting Upgrade||?W||?W||April 2006||bath, basement T12 fluorscent upgraded to T8 & reduced from 20 T12-40 to 7 T8-32 lamps|
|Lighting Upgrade||?W||?W||1999?||most used lamps (living room) upgraded from 60W to 11..15W CFPopular Mech USA says home avg is 940 kWh/yr for lighting|
|TOTAL||70W||3.3W||82W total (32% of 2006 average use!)|
Adding Things Up
Here is a summary of usage - trying to reconcile what the hydro meter says and what my calculated power use is
|Season||Nighttime (vampire) |
|Appliances + Seasonal |
|Billed Use |
|Summer||28W||166 + 32W||9.25W||235W||260W|
|Winter||47W||166 + 67.5W||20.75W||301W||330W|
|Aug 2007||??W||??W||0W||144W||3.33 days nobody home|
For the Aug 2007 measurement it was 12.74 kWh over 3 days 4 hours with a 15W CF lamp left on by mistake. The electric water heater used 22W average draw during that period. The frige and freezer should be around 40 + 50W leaving 54W for basement dehumidifier (est 30W average) and vampires (15W measured and calculated).
I was surprised to learn that some modern items draw as much electricity when they are off as when they are on! This typically includes printers, home stereo and VCR equipment.
Home Electrical Vampires
Our home uses 31W (0.35 hydro meter rotation in 4:53, June 2006) at night when nothing is on. When I unplug the microwave, water softener and central vac. (16W total) then power use drops to 15.4W (0.10 rotation in 2:48). If I turn off the power bar to the computer (14W draw) then the hydro meter doesn't rotate even though there are something like 21W in vampire devices still plugged in!
Here is an excellent duplication of what I measured and it sums it up nicely with: Why pilot lights are evil.
Stuart Staniford has a neat piece of his home energy improvements: sanity checking energy improvments.
I was wondering - how does it compare to heat the house with natural gas vs electric resistance heating. Also - what is average energy loss of the house thru the winter:
Given 60% gas furnace efficiency, 1 ccf = 103,000 BTu's and 1 kW = 3413 Btu/h
400 ccf natural gas typical winter use in 8 months = 7300 Btu/h = 1.3 kW average!
The worst month is: 110 ccf / Jan = 2.8 kW average.
Ok - reality test. We spend about $450 / year heating the place and I
know that electric water heating is 2x to 3x as expensive as natural gas.
2.1kW * 8 months = $870 / year ($0.10 / kWh)
So it's about right and it's 2x as expensive to heat using electric heaters.
Our oven/stove-top uses aprox $4 / month of electricity. "Self cleaning" ovens are touted as being more energy efficient because they have more insulation. They typically cost $100 to $150 more and save you 4% of your energy or about $2 per year in our case. So it's not something we're buying as we have no use for a self cleaning feature.
Office of Energy Efficiency - EnergyStar program has excellent information rating modern equipment.
My home taxes ($2500) are 2.5x more expensive than the total heating ($500 home & $120 water heating + electricity costs $300). There is no incentive to reduce energy use!
With the failure of nearly all window seals (15 year old Golden Windows) in our house in the first 2 months of the 2005 Winter I started looking into upgrades. Windows of our vintage used a butyl edge around the outside. It was crudely applied - rounded at the corners. With age the butyl is cracking. Note that our failed windows were on all sides of the house - some NEVER getting direct sunlight!
Windows can be upgraded (to low-E, argon, warm edge) as follows:
A typical vinyl sash is an open cavity - so for about 1" all around the window you've got perhaps R2, if you're lucky, due to the air gap and 2 vinyl layers. By filling this, even 1/2 way, with foam insulation you'll increase the R value to R4 - in excess of the R3 of an efficient glass window. Be sure not to overfill as it can warp the sash and create many problems.
The effect of low-E, Argon filling is readily measureable with a simple home thermometer. Here are some
measurements done at the centre of the window:
|Condition||Temperature Difference At Glass|
Between Inside Air and Glass Surface
(0C outside, 20C inside)
|Good double glazed window||reference (typically 3.5C below air temperature)|
|Failed double glazed window with misting||0C|
|Failed double glazed window - measured where water filled||-1.25C|
|Low-E, Argon double glazed||+2.5C (typically 1.25C below air temperature 4" from window)|
|Close thick curtains||-2 to -3C|
Calculations on window energy efficiency upgrades.
|Vinyl Living Room|
double glazed, "warm" butyl seal
|1.88 (U 0.53)||uninsulated sash 1.5" wide, window 1/2" into sash|
3.72 ft^2 glass, sash cavity 0.42 ft^2 + 0.25 ft^2 edges
|Upgrade glass to low-E,argon (R3)||3.19 (U 0.31)|
|Upgrade glass to low-E,argon (R3)|
foam fill sash cavity
|3.54 (U 0.28)||sash cavity filled with foam, un-modified sash edges|
|Bedroom window (basically as above) 33x20"||1.75 (U 0.57)|
|Bedroom window R3 glass upgrade||3.24 (U 0.31)||Low-E,argon glass|
|Bedroom window R3 glass & foam filled cavity upgrade||3.56 (U 0.28)||Low-E,argon glass, sash cavity insulated|
Curiously enough - I converted the four mains (120Vac) connected smoke detectors with battery operated ones and that nearly exactly balanced the increase electricity load caused by washing and drying diapers every 6 days (20W continous or 440 Wh/day). This just goes to show the power of vampire appliances when compared to legitimate use of something, a clothes drier, that is power hungry when used!
|Washer||Measured Electricity Use||Water (wash [hot] / rinse [cold] = total)||Energy Star Rating||Drier time for a typical load||Notes|
|Front Loading (Kenmore - 2002 model)||?? w-hour||20L / 78L = 98L||196 kwh/yr||60 min||regular load, high speed spin, 370W peak draw during spin|
|128 w-hour||20L / 92L = 112L||196 kwh/yr||60 min||regular load, extra rinse, high speed spin, 51 min washing time, 370W peak draw during spin|
|Top Loading (Kenmore - aprox 1985 model)||170 w-hour||60L / 90L = 150L (aprox $0.25)||aprox 1,000 kwh/yr||90 min||regular load, aprox 25 min. washing time|
This is from the Environmental Newsletter.
"Washing machines are the 2nd largest user of water in residential households. Over 20% of indoor residential water use is for clothes washing. .. average household using a toploading washer this represents 362 loads of laundry, 54,300 litres of water and 1,000 kW hours of electricity per year. (This equates to 150L/wash or $0.25 water and 3kWH or $0.40 in electricity per load.)
Efficient front-load washing machines save 40% of water and 50% of energy."
Nov 2007 we replaced the shower heads with the following model. It allows for very low flows of water while working well. (From Home Hardware) EuroStream B11023CP "3 Setting Fixed Showerhead" rated "Water Saver under 2.5 GPM"
For my home, with natural gas heating, the hot water represents aprox 1/6 of the natural gas usage. Given that we don't use that much hot water - I find it excessive. Aprox $70 / yr in gas is spent keeping the water tank hot and about $40 / yr in heating water for use. I often leave it set at the "vacation" temperature as that is hot enough for showers and dish washing. The city is trying to upgrade me to a larger model as they claim that a 40 US gal water heater isn't big enough for 2 people - much less a family of four.
Note: The city came back with an interesting offer - a high-efficiency (96% - Polaris) water heater. Then the water heater uses an "air handler" to heat the house! It sounds good. That way we get efficient water as well as heating. The snag is that the rental costs are $37/mo much more expensive than the current water heater ($8/mo) and we'd only save $150/yr in reduced natural gas use - so it would COST us $167 / year to have more efficient heating.
Electric water heater (GSW) costs for 2006 models:
sub 40gal not-tested (ie 10L)!!
40gal 57->71 W/h
60gal 75->96 W/h
There are 3 main uses for hot water in our house:
Here is an interesting product which recovers waste heat in water and
is best used with in-line "tankless" water heaters where water is used
and dumped at the same time.
Power Pipe - Heat Recovery and GFX Gray Water Heat Recovery and GFX test results
These figures are from white-rodgers.com
1 Btu = 252 calories
1 Btu/Hour = 293 mW (1W = 3.413 Btu/Hour)
1 HP = 746 W
Natural gas 950 to 1150 Btu/Cubic foot (No 2 Oil is 140,000 Btu/gallon)
Butane = 3,200 Btu/Cu ft (propane 2,500 Btu/Cu ft)
So heating the water tank (33 gal in one hour costs:)
Natural gas: 33 gal * 4.5L/gal = 149 L * 50C = 29 Cu ft gas or $0.32
Electric heating: 8.6 kW for 1 hour = $1.00
During the winter of 2006 I started testing our low efficiency gas furnace. It's nameplate rating is about 75% efficiency. But that drops to an estimated 55% if it's cycled at 1F and 62% at 1C temperature swing. So I modified the thermostat by wrapping it in an insulator and then metal to add a time delay (12% longer furnace runtime, estimated 64% efficiency). Now the furnace runs 12% longer and the temperature swing is increased for an estimated 2% better efficiency. In the morning our house goes from about 17.5C to 22C and that takes 1 hour runtime and should be approaching 75% efficiency.
Two years ago we upgraded from a low efficiency (standing pilot Lennox G8) furnace to a high eff one.. Here is the summary of our natural gas use:
Average yearly use went from 600 ccf to 210 ccf - a reduction of 65%.
Peak use in the winter was reduced from about 90 ccf/month to 50 ccf/mo - 55% decrease.
The peak use didn't drop as much as the average because the old Lennox G8 furnace was very aprox. about 50% efficient when cycling on and off and 75% when running all of the time (steady state). When it's very cold the furnace ran much longer, instead of short cycles, and so approached it's 75% nameplate efficiency.
The pilot light was 1/4 of the total furnace gas use. Our gas water heater was 1/6 of our total gas use.
The above calculations assume that the following improvments were not used:
1) turning off the pilot light when the furnace was not in use
2) tweaking the thermostat to increase the furnace run times - and improve efficiency and temperature swings.
A "DC motor" furnace was a $1k to $1500 option. As it would save a projected $6/yr it wasn't worth it given the average furnace life of perhaps 20 years. These motors are actually called ECM - Electrically Commuted Motors. A regular motor is known as PSC - Permenant Split Capacitor. The ECM advanage is that at lower speeds they have much higher efficiency. Typically they are, at best, 1/2 the power consumption.
Using this I tried to estimate the savings of a DC motor. Basically from the 2nd article The Electric Side of Gas Furnaces a graph of power vs airflow revealed that ECM motors use about 60% of the electricity of a PSC motor. From that our savings in electricity are about $6/yr. This is based upon 230 hours/year and a savings of 260W during that = 60kWh at $0.1/kWh = $6/season. This is partly because we run our furnace at low speed for heating. What I can't reconcile is the article below which shows a PSC motor at 350W for low power (our furnace is 650W) while an ECM motor would use 284W.
From The Impact of ECM Furnace Motors on Natural Gas Use and Overall Energy Use During the Heating
Season at CCHT Research Facility Sept-Oct 2002:
Condition, ECM Motor, PSC motor.
Circulate, 17W, 350W (low speed)
Heat, 284W, 490W (medium speed??)
Condition, ECM Motor, PSC motor.
Circulate, 211L/s (13m^3/min 434cfm), 454 L/S (27m^3/min 934 cfm)
Heat, 573L/s (34m^3/min 1170cfm), 622 L/S (37m^3/min 1280 cfm)
From The Electric Side of Gas Furnaces Home Energy Nov/Dec 2003 http://www.HomeEnergy.org:
1/2hp PSC 400W (850cfm) to 560W (1100 cfm)
1/2hp ECM 20W (400cfm) to > 1100 cfm at roughtly 60% the power of a PSC motor
York GY9 ratings at 0.5" (0.124kPa) static pressure (no filter):
High speed 1415 cfm, 40m^3/min
Med-High speed 1160 cfm, 33m^3/min
Med-Low speed 955 cfm, 27m^3/min
Low speed 750 cfm, 21m^3/min (aprox 450L/s)
I measured on our York GY9 furnace (fan only):
Low speed: 650W (785W when heating with combustion fan)
Med-Low speed: 805W
Our old 1990 vintage Lennox G8 low-eff gas on low speed was 383W
Our low efficiency gas furnace has a pilot light. It consumes 5.4 ccf / 30 days or 0.3 ccf/day. Our
yearly average gas consumption is aprox 1.8 ccf/day and that includes water heater.
The water heater is dominated by it's pilot light - 0.18 ccf/day (measured over a
2 minute interval) and aprox 0.1 ccf/day heating water).
That means that the furnace pilot light uses aprox 0.2 ccf/day out of 1.5 ccf/day used for air heating or 15% of our total natural gas used for heating!!!
May 14, 2006 I measured the gas use for furnace + water heater pilot lights and got:
2/10 cu ft in 4:20 = 67 cf/day
7/10 cu ft in 19:55 = 51 cf/day
9/10 cu ft in 30:20 = 43 cf.day
Since the water heat itself draws 18 cf/day the pilot for the furnace is aprox. 25 cf/day
This clearly means that we can increase our furnace efficiency by about 15% ($80 / year estimated by actually $50 / year because we turn the pilot light off for 4 months of the year) by having an electronic ignition!
Our total gas consumption is 500 to 600 ccf per year for a family of 2 with 2 preschoolers. That breaks down to about 80% for the furnace and 20% for the water heater.
Analyzing summer consumption; in years when the furnace pilot light was turned off, and by measuring the water heater pilot light directly, I was able to breakout the following:
|Summer water heater total||0.21, 6.3||pilot + heat, $84/yr|
|Water heater pilot light||0.18, 5.4||$72/yr, standing pilot light, keeps tank warm|
|Calc. water heater heating water||0.03, 0.9||$12/yr|
|Summer water+furnace pilot lights||0.50, 4.5||$201/yr|
|Calc. furnace pilot light||0.29, 8.7 (measured aprox 0.25)||$116/yr (15% of furnace use)|
|Total House Use||1.8, 54||Estimated from a 2003 winter, heating house all day for kids, $723/yr|
|Calc. furnace heating house||1.59, 48||$638 (85% of furnace use), heating runs 8 months/year, 412 hours Dec19-May 10|
Here is raw measurements and calculations of our furnace runtime:
Warmup: (min) 2.34 Assume all energy in warm-up phase is lost, 5 sec ignition delay Base Efficiency 76% 41,800 Btu/h output 55,000 Btu/h input Delta T Run Run/Min Effic. Net Fuel Delta Comment (C) Time Lost Effic. Wasted Loss 0.56 6.21 11.2 27.3% 55.2% $123.07 1 deg F estimate 1 11.17 11.2 17.3% 62.9% $77.83 $45.24 2 23.06 11.5 9.2% 69.0% $41.40 $36.43 3 34.59 11.5 6.3% 71.2% $28.47 $12.93 Est based on 2 Deg measurement 5.5 61.17 11.1 3.7% 73.2% $16.56 $11.92 1.12 12.48 11.2 15.8% 64.0% $70.96 Insulated thermister Try to verify eff. change by comparing 2 vs 1 Deg run times - should have lower run time (of total time?)?? Modified thermostat on Jan 14 with 12% longer run time by adding thermal mass and insulating thermostat Thermostat Runtime Totals - note counts 2.25 min warmup, not 1 min. cool-down Run time per 1C 13.62 Run time/1C modified 14.92 (furnace thermostat modified)
Kitchener Utilities says (April 2005) that the average house uses 2,600m^3 per year. Our
consumption is around 1,500 m^3/year.
Natural gas was $0.10 per m^3 upto May 1999, peaked at $0.27 in winter 2001 and fell to $0.15 in the summer of 2002 and then followed an upward trend to $0.27 in 2004. Delivery charges add aprox $0.11 per m^3.
This heating budget is from our Home Energy Evaluation:
Have you ever considered a waterless toilet? If you are considering a low flush toilet I'd highly suggest that you only consider models tested and approved by the City of Toronto. The Waterloo Region water web site has compiled some water test results and the Seattle on in particular shows no correlation between toilet price and performance. Click on "residents" on the left and then on "toilet replacement program" and look for the link called "toilet testing".
March 2005 - water rates are raised from $1.774 / m3 to $2.09 and this is apparently an increase of $6 to $7 for the "average" household. That means that the "average" family uses 20 m3 / month which is a good 5x what we use with our kids in cloth diapers that we wash at home!
While taking a shower I use 5 to 7 litres of water per shower while a more typical person is around 20 litres. I can cut my usage of water to 3.5L by turning off the water while lathering. To put this into context - a low flush toilet uses 6L and older toilets use > 12L per flush!! Having a shower daily means that 10% of my total water usage is consumed with showers.
A side effect of my water consumption is that I use so little water showering (1.5L/min or 0.35 US gal/min) that no in-line or "tankless" hot water heaters would not turn on as they all require 0.66 to 0.75 gal/min!
|Country||Annual per capita water use m^3||Water cost per 1,000L|
|Our Household Family use||50||$1.00|
|Fall 2005 Kitchener Environews Flier|
Just how is water in our household used? Useage was 26 cubic meters / yr when I lived alone and that rose to 40 cubic meters / yr with 2 of us. Now - with twins and washing diapers every 2 days that is aprox 80 cu. meters/yr. However, once we purchased a front load clothes washer and the diaper washing was reduced to weekly our water consumption droped back to 50 m^3 per year.
The Canadian average is 326L / person / day of which 1/3 is used by toilets.
I strongly recommend flourscent lighting for areas where the lights are being used
more than 1 hour / day. The Philips Marathond flourscent lamps in particular give
a soft white light that is flicker free. The bulbs are expensive but will reward
you with a reduced electricity bill.
The compact flourscent lamps don't use the old style of transformer to generate the high voltage but instead use an electronic circuit and much higher frequency. For that reason they can't flicker and are much more efficient than the old style flourscent lamps. You get what you pay for in the sense that lower cost compact flourscents have a shorter life and are less efficient.
Lamp Electricity Use and Car Emissions Measurements
My wife and I generate one bag of garbage
every 4 or 5 weeks and fill the recycling box every 6+ weeks. The recycling
box is primarily filled with unsolicited newspapers and filers. Boxboard
[cerial boxes] and 2L pop bottles make up a small part of the material and
we almost never use metal cans.
The non-recyclable garbage which we produce is primarily wrapping from items (food, etc) which we purchase. We compost what things we can.
A typical lawn mower puts out as much pollution as a car. Why? There is no pollution control equipment, poor control over the fuel mixing and a basic design (2 stroke) that burns oil.
I've recently bought a Yard Works "reel" lawn mower. This is the old style
of push mower that literally cuts the grass. Cutting blades virtually cut the grass
like scissors. The Yard Works mowers are made in China. German made ones
such as Gardina are about 2x the price, lighter and probably much better made.
Gardina does make an electrically powered push mower. I still go into laughing fits when I think of it!
Problems: The reel mower did not come with lock washers and so I had to add them and the parts were not manufactured well. In particular the arms for the handle were not well bent and most importantly, the cutting blades were not well aligned. If I adjust the cutting bar such that the mower cuts in the middle; the outer 2 or 3" at each side does a poor job of cutting. Moving the cutting bar more will make the mower do a better job of cutting; but it also makes it noiser.
Here are graphs of our home energy and utilities usage:
Utility Their My Average Use Elec $717/yr $200/yr Gas $700/yr $500/yr Worse yet; they assume that hot water heating consumes 1/3 of the natural gas consumed!! My calculations show summer use = 13 ccf [water heating] winter use = 93 ddf [furnace + water heating] Therefore space heating consumes 7x more natural gas than the water heater! Basically, their pie charts for energy usage are totaly useless given how far their average home deviates from mine. Be sure to point that out to them and pre-calculate some of your own usage figures to see if they're even close to your actual consumption! Their pie chart included: Average My Home Home Space heating 49% 60% Hot Water 28% 12% Electricity 22% 28% ------ ----- $1410 $700 [per year] 5.3 air changes per hour "tight" $500 [59100 ft2 / year for nat.. gas [$90/yr for water heater] $18/mo [200 kwh] 1/3 = freezer + fridge Fall 2001 - switched to compact flourscent lights in regularily used lighting fixtures. Summer 2005 - switched T12 fluorscent lights to T8 and cut most fixtures from 4 or 2 lamps to 1 or 2.