Green / Eco-Friendly

Mysterious electrical energy savings

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Mysterious electrical energy savings

My wife and I are in our almost all-electrical house for the second year. Our electrical energy usage is running at 26% lower over the previous year (our first full year in the house) running late October- late October according to the utility (BC Hydro) with 83 days to go. How the energy savings have come about is a mystery. We had counted on a reduction in consumption for the first couple of months of the 2nd year but not later in the heating season or the over the summer. Consumption was down 30-36% early in the second year (see explanation below) which was expected but that settled down to 26%, even over the summer thus far, which was unexpected.
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In beginning of the first year, I had already replaced most of the regularly-used lights with LEDS and CFLs (previous owners loved and used lots of incandescent lights - there were over 80 track light fixtures and two chandeliers that used 9 x 60W bulbs). I also reshimmed doors so they were sitting squarely in frame as you could see light through many of them (had to do that again later in the year as the cardboard I used compressed so I replaced these with plastic shims). Probably the biggest saver - done late in the calendar year, relatively early in the heating season and challenge year - was to replace the non and then a simple programmable thermostat with an advanced OEM one which allows auxiliary heating lockout (we only allow that when outside air temp drops below freezing). The two previous thermostats allowed the heat pump auxiliary heating to engage as soon as (or soon after) the heat pump came on. In the middle of the heating season, we got a chest freezer (house came with a refrigerator only which we still have). One other change was to deactivate and/or replace motion-sensor lights. Previous owners had too many hardwired (couldn't switch them off except at the circuit breaker panel). When some of these were staying on, I deactivated them by unscrewing the bulbs. These were replaced with new ones which were switched (found the unused wire for a swicth I couldn't figure out what it was for) so you could turn them off.

In the second year (~ 1 month into the savings challenge year), we had a somewhat-unexpected need to replace the electric hot water tank and went from a 60 IG (we think) tank to a 42 IG one. I did take out the HW recirculation pump (and will reinstall it sometime) but we never used it. The new HWT has 3" of foam insulation and is supposed to cool only 5F over 24 hrs. 2nd month into the challenge year, we topped the attic insulation to ~R-55 and tightened down the attic hatch (will double insulate it). There appears to be some result (did a regression of power consumption and average outside air temp before and after) though it didn't help so much with an unseasonably-cold February where power use was higher than the year before. Doors were squared better so they leaked less. I also had insulated the 3 light tunnels better to prevent warm air from getting into the tunnel. Still doesn't explain the reduced non-heating season/summer usage. AC was used perhaps 10-20 hours the previous year due to heat and excessive smoke from forest fires. I did tape up the ducting to minimize heated air leak but I understand this is a wash.

No real change in heating usage (we're home most of the time) or light usage. Not using the electrical cooking elements or oven any less. No real change in laundry (haven't increased hang drying anymore and we only use the dryer ~once in every 8-12 loads or more and only for the dish towels and rags). A few more track lights were converted to LEDs but these are not used very much (bulk of them are the transformer ones so change to LED probably won't save much so we don't use them). One big change was finding the cause of water in the glass-enclosed sun room (there was a leak in the roof). We don't heat the space in winter like the previous owners did (would explain their reported $600 p.m. electrical bills in winter when power here is $0.12/KWh max). We still use the dehumifidier and fan in there (condensation on the glass when the temperature drops substantially overnight to 0C or colder), but this has been reduced over the previous year with the leak fixed. I did put foam insulation between the glass wall and roof but this is very marginal and space is unheated. On the entertainment front, a bigger pair of speakers and a second subwoofer (latter on standby and I don't always turn off the power bar at night) have entered the house. The main stereo system has got the preamplifier back but these are not used much (I imagine they - tube CD player, tube pre amp and pair of tube power amp monoblocks - are power hogs).

Going into the next heating season, all we have for usage reduction is an ECM motor in the air handler which may save a couple of 100Wh.
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You covered some big ones
The circle pump is a huge waste of power both in the pump itself and the waste heat in the hot water flowing.
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tebore wrote: You covered some big ones
The circle pump is a huge waste of power both in the pump itself and the waste heat in the hot water flowing.
The HW circulator was never used (might have already been unplugged before we move in, if not shortly after) though, and there was a shut-off valve too, which I used so it wouldn't circulate by convection (for want of a better term).

If there is one saving grace about the hot water circulator, it's that it has a timer switch. Again, not that we ever used the circulator in the house. My wife's late parents had one in their house (installed by the previous owner(s) AFAIK). Between this and the very organic and metal-heavy water, HWTs only lasted 4 years.

The 2nd challenge year will be interesting. I doubt we can save a further 10% unless the net power savings with the ECM air handler motor is that significant (the HP seems to run all the time once the outside temp gets to/close to/below 0C) so that's a couple of hundred W there - maybe 2KW/day- + the motor runs cooler so the HP has to work more. The heat strips boosted consumption significantly so we won't be using that to reduce run time.

I should add the only reward for reducing consumption by a weather/temperature-adjusted 10% is measly $50.
Last edited by thriftshopper on Aug 12th, 2019 1:50 pm, edited 1 time in total.
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thriftshopper wrote: The HW circulator was never used (might have already been unplugged before we move in, if not shortly after) though, and there was a shut-off valve too, which I used so it wouldn't circulate by convection (for want of a better term).

The 2nd challenge year will be interesting. I doubt we can save a further 10% unless the net power savings with the ECM air handler motor is that significant (the HP seems to run all the time once the outside temp gets to/close to/below 0C) so that's a couple of hundred W there - maybe 2KW/day- + the motor runs cooler so the HP has to work more. The heat strips boosted consumption significantly so we won't be using that to reduce run time.
Since this a year round thing not just winter, you can add a solar water heater and vent-less dryer. Also can try putting in skylights if there is area of the house that you find that you use lights in the day time.
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The roof will make installing a solar water heater a challenge here (concrete tile - abandoned the idea of rooftop solar electric), but glad to see there are freeze-proof versions. I'd like to see how much how heating water costs but I don't think we use very much. Would like to turn down the temp setting precisely because we don't use very much (but supposedly listeria may become an issue). I doubt we use enough hot water to make the solar water heater pay for itself.

The condensing dryers are intriguing but we already hang dry almost everything (my wife draws the line at rags and dish clothes while I will hang those to dry). Again, the dryer sees so little use that any increased use - no matter how efficient the dryer - will bump up consumption. Due to the configuration of the laundry room (due to last-minute change from the architect's plans), we'll be forced to replace both the washer and dryer (if we want the latter) if one, especially the former, quits.
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thriftshopper wrote: The roof will make installing a solar water heater a challenge here (concrete tile - abandoned the idea of rooftop solar electric), but glad to see there are freeze-proof versions. I'd like to see how much how heating water costs but I don't think we use very much. Would like to turn down the temp setting precisely because we don't use very much (but supposedly listeria may become an issue). I doubt we use enough hot water to make the solar water heater pay for itself.

The condensing dryers are intriguing but we already hang dry almost everything (my wife draws the line at rags and dish clothes while I will hang those to dry). Again, the dryer sees so little use that any increased use - no matter how efficient the dryer - will bump up consumption. Due to the configuration of the laundry room (due to last-minute change from the architect's plans), we'll be forced to replace both the washer and dryer (if we want the latter) if one, especially the former, quits.
Induction stove top instead of a standard heating element.
Geothermal heating and cooling .. it starts to gets expensive once youve done the basic conservation.
BTW the ventless dryers are >100% efficiency and they add moisture to indoor air during winter,
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Supahhh wrote: Induction stove top instead of a standard heating element.
The previous owners had an electric cooktop, exact type unknown but probably GE, until they saw the neighbours' new 6-burner Viking range and hood. In a fit of jealousy, they put in a Miele "domino" CombiSet so we have 2 "tiles" with 3 propane burners total and 1 tile with 2 IR rings. Unfortunately, the style we have is obsolete, and the replacement piece is too wide, and Miele pieces are not cheap (US$1,500 for the induction tile!)

Geothermal heating and cooling .. it starts to gets expensive once youve done the basic conservation.
So I understand, especially so as the ground here is mostly volcanic rock and on a slope (drop 40m from top to bottom). Solar would have been good if our exposure was set for straight south but the house wasn't built that way. Also lose a lot of the later afternoon sun due to terrain.
BTW the ventless dryers are >100% efficiency and they add moisture to indoor air during winter,
Are the ventless dryers heat pumps?

We don't want extra indoor humidity where we are. Indoor RH is in the very low 60% range all winter - w/o a humidifier!
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thriftshopper wrote: The previous owners had an electric cooktop, exact type unknown but probably GE, until they saw the neighbours' new 6-burner Viking range and hood. In a fit of jealousy, they put in a Miele "domino" CombiSet so we have 2 "tiles" with 3 propane burners total and 1 tile with 2 IR rings. Unfortunately, the style we have is obsolete, and the replacement piece is too wide, and Miele pieces are not cheap (US$1,500 for the induction tile!)
your options are getting fewer and fewer. If you can find the induction tops. Induction is far more efficient than IR,
thriftshopper wrote: Are the ventless dryers heat pumps?

We don't want extra indoor humidity where we are. Indoor RH is in the very low 60% range all winter - w/o a humidifier!
yeah they are heatpumps.



The biggest energy consumption devices I think are stove, home heating , water heating , clothes washer and dryer , Dish washer ( not necessarily in that order ). ( also if you have a older cable box or a satellite receiver )

Pretty much your last option is a heatpump water heater? I realise you already replaced yours recently , but these are desperate times.

http://www.gsw-wh.com/en/products/heat-pump
https://www.rheem.com/products/resident ... ng/hybrid/

Other than that , get a ir camera attachment for your phone and check for leaks on windows. maybe some of them are old and have leaked the argon from them?
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Supahhh wrote: your options are getting fewer and fewer. If you can find the induction tops. Induction is far more efficient than IR,
We'd like to keep the gas cooktop, just in case power goes out. The base cabinet is pretty much maxed out so we can't fit in the modular induction top. We'd have to replace everything and I don't believe in replacing good, functional appliances, or remodelling the kitchen (we think major renos are pointless so chose to buy a house we could mostly live with).
The biggest energy consumption devices I think are stove, home heating , water heating , clothes washer and dryer , Dish washer ( not necessarily in that order ). ( also if you have a older cable box or a satellite receiver )
We do use the cook top and oven quite a bit (oven probably more now as I am baking more bread now) so the latter won't explain reduced electricity usage. May have switched to using the gas cookers more now that we have a better extractor fan (the still-installed downdraft was horrible) so might have reduced use of the electrical cook top. The overhead extractor fan may consume less power than the downdraft too.

No real change in clothes dryer, washer and dishwasher usage (latter I use heat booster as we now have cats and I want to sterilise their dishes if it's being washed with ours). Overnight consumption of power shows 1 modem, 3 routers + 2 subwoofers and phones isn't very much compared to daytime. Do have a 2nd subwoofer also on standby in the 2nd year (I often forget to turn off the power bar).
Pretty much your last option is a heatpump water heater? I realise you already replaced yours recently , but these are desperate times.
There is a rebate for this in B.C. currently. However, correct me if I am wrong, but won't a heat pump cool a house in winter making heater work harder? It seems to be a better idea where year-round temperatures are milder.
Other than that , get a ir camera attachment for your phone and check for leaks on windows. maybe some of them are old and have leaked the argon from them?
There are a few French doors that are poor (cheap builder grade), and a couple of failed (small) windows. I'd like to get the Euro-style doors (has locking 2 pins each on both the to and bottom and 3 to the other door) for better air-tight seal but these cost $3,000 cash 'n carry (i.e., no delivery and installation).
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thriftshopper wrote: We do use the cook top and oven quite a bit (oven probably more now as I am baking more bread now) so the latter won't explain reduced electricity usage. May have switched to using the gas cookers more now that we have a better extractor fan (the still-installed downdraft was horrible) so might have reduced use of the electrical cook top. The overhead extractor fan may consume less power than the downdraft too.

No real change in clothes dryer, washer and dishwasher usage (latter I use heat booster as we now have cats and I want to sterilise their dishes if it's being washed with ours). Overnight consumption of power shows 1 modem, 3 routers + 2 subwoofers and phones isn't very much compared to daytime. Do have a 2nd subwoofer also on standby in the 2nd year (I often forget to turn off the power bar).
did you have a cable box or satellite receiver before? that might account for the energy savings. ( those things used about 80-200W 24/7 regardless of if you were using them on not).
For the extractor Fan, instead of venting it out, using a vent-less carbon filter based fan helps with retaining heat /cool air in the house.

thriftshopper wrote: There is a rebate for this in B.C. currently. However, correct me if I am wrong, but won't a heat pump cool a house in winter making heater work harder? It seems to be a better idea where year-round temperatures are milder.
you are correct the Water heating would be transferred to the heatpump for the house.

I think Im out of ideas except for waste water heat recovery.
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Supahhh wrote: did you have a cable box or satellite receiver before? that might account for the energy savings. ( those things used about 80-200W 24/7 regardless of if you were using them on not).
We had a cable box before, but switched out.... ~4 months into the 1st year for IPTV service and devices. The cable devices and modems for the cable devices must have used a lot more power than the IPTV devices in that case.
For the extractor Fan, instead of venting it out, using a vent-less carbon filter based fan helps with retaining heat /cool air in the house.
A possibility but I ended up buying an extractor instead of a recirculator (the manufacturer offered both). An air leak conduit would have been avoided.
I think Im out of ideas except for waste water heat recovery.
I had a look at these devices and was astounded by the prices. The dishwasher and clothes washer would be evident places but I don't see any cost recovery potential.
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thriftshopper wrote: We had a cable box before, but switched out.... ~4 months into the 1st year for IPTV service and devices. The cable devices and modems for the cable devices must have used a lot more power than the IPTV devices in that case.
yup that they do.
thriftshopper wrote: I had a look at these devices and was astounded by the prices. The dishwasher and clothes washer would be evident places but I don't see any cost recovery potential.
you can thank the regulators for the price increase. since i they made it mandatory for new contruction. couple with patents for this simple device means there is not much competetion.

however, If youre willing to DIY it, a much much simpler version can be made with pretty much the same efficiceny. all you need to 2 tubes say 3" and 4" ( in case you drain is 3" ) and slide one over the other , seal at both ends with a copper tube ring and weld it. put in connectors for the water inlet and outlet.

Here's a simple drawing what its crosssection might look like.

inlet 1" tube welded to 4"pipe. .outer shell 1" outlet tube welded at the other end of 4" pipe.
O---||------------------------------------------------------||----O ring made of 1/2" tubing welded all around the 3" pipe and 4" pipe.
------------------------------------------------------------------------------------------
3" inner pipe ( waste water flows thru here )
------------------------------------------------------------------------------------------
O-------------------------------------------------------------------O

shouldnt cost more than a couple hundred $
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I think I have proverbially picked all the low-hanging fruit as far as power savings go.

Still not sure how so much was saved over the previous full year of occupancy, however, given that I had reduced some of the power-wasting usages.
Supahhh wrote: yup that they do.
Wonder if there is a difference between the equipment that cable (Shaw) and IPTV (Telus) use? I think the Telus STB/PVR equipment (used to be Microsoft hardware and firmware, which was sold off to Cisco/Scientific Atlanta and is now made/sold by Arris, which - I understand - makes a lot of cable TV boxes) may consume less than the equipment Shaw used.
you can thank the regulators for the price increase. since i they made it mandatory for new contruction. couple with patents for this simple device means there is not much competetion.
As for the heat exchanger for fresh and hot grey water, I can see the benefits in a building where there is a huge amount of water being used but don't see much practical value in a house where the drains are spread out over and there aren't that many people. I assume the principle is that the warmer grey water warms up the incoming fresh water? This may make sense if there is a somewhat continuous and equal flow (such as people showering or running the kitchen faucet to do the dishes) but not if the flows of water are not equal. Say I fill a bath tub, or washer, or dishwasher, there won't be any warmer gray water to heat the incoming fresh water than replenishes the tank, and when those devices are drained, there won't be any incoming cold water to be warmed up.

I'd also worry about contamination due to separation failure.

For this purpose, I think a solar water heat makes much more sense. Just wish I could have one installed and cheaply.
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thriftshopper wrote: Wonder if there is a difference between the equipment that cable (Shaw) and IPTV (Telus) use? I think the Telus STB/PVR equipment (used to be Microsoft hardware and firmware, which was sold off to Cisco/Scientific Atlanta and is now made/sold by Arris, which - I understand - makes a lot of cable TV boxes) may consume less than the equipment Shaw used.
all of them are energy hogs. simple enough to test using a watometer. The isue is even if you want to turn it off, the cable /satellite company wants them On all the time to update software / channel list / subscription etc.
thriftshopper wrote: As for the heat exchanger for fresh and hot grey water, I can see the benefits in a building where there is a huge amount of water being used but don't see much practical value in a house where the drains are spread out over and there aren't that many people. I assume the principle is that the warmer grey water warms up the incoming fresh water? This may make sense if there is a somewhat continuous and equal flow (such as people showering or running the kitchen faucet to do the dishes) but not if the flows of water are not equal. Say I fill a bath tub, or washer, or dishwasher, there won't be any warmer gray water to heat the incoming fresh water than replenishes the tank, and when those devices are drained, there won't be any incoming cold water to be warmed up.

I'd also worry about contamination due to separation failure.

For this purpose, I think a solar water heat makes much more sense. Just wish I could have one installed and cheaply.
I believe the minimum requirement for regulation certification purpose is that they reclaim 42% of the energy ( there are some available which recover upto 65%). So that's a big recovery. So technically your water heater bill should go down by that amount. Since its installed in the one main outlet, it means whenever water goes out, its heat is recovered and since an almost equal amount is going the other way . It sort of makes sense.

As for cross contamination, since the supply water is under pressure and the return to drain is not, if there is a leakage it will always be fresh water leaking into drain. not the other way around. If you get a commercially made one. its double wall insulated ( drain pipe wall + tube of supply water. But even a single wall construction should be fine as copper pipes last forever and if you diy , you can pick and choose the thickness of the pipe.
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YTD including August, which was only down 10% from a year earlier. That's more inline with what is expected.
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