Free energy inspection by our local electric company

[simple girl]

Just had a free energy inspection from our local electric company - it was great! I learned quite a few things that we can apply right away. One of the biggest was not understanding that we have a 2 stage heating system. We turn our heat down at night and back up in the morning. If the differential between the ambient temperature and the temp we set it at is > 2 degrees (i.e. it's actually 60 deg and we set it to 68 in the morning), our Stage 2 heat system kicks on...which costs up to 5x as much per hour to run. Who knew? Not us, apparently.

He pointed out several other insulation tips, etc.

Sharing this in case others might want to see if their local utility company offers a similar free service.

[ERD50]

I think there are thermostats designed specifically for this. IIRC, they can be set to be more 'conservative' about kicking in the second stage. Maybe more time delay, or they look at the ramp time or something. You might even be able to turn off the stage 2 manually - only use it when you feel the need?


-ERD50

[Sarah in SC]

I've suggested that energy audit to some folks in the past. At our electric co-op, there is one guy covering 3 counties, so he'd rather talk to you on the phone than actually come out to the house!
I'm glad it worked out for you, especially that tidbit about the heating. I need to find out about that for ours.

[simple girl]

Quote:

Originally Posted by ERD50 I think there are thermostats designed specifically for this. IIRC, they can be set to be more 'conservative' about kicking in the second stage. Maybe more time delay, or they look at the ramp time or something. You might even be able to turn off the stage 2 manually - only use it when you feel the need? -ERD50

There probably are but since DH works from home a lot, he will more than likely opt to just gradually turn it up by 2 degrees throughout the morning. He gets up about an hour before me, so thankfully he starts getting it warmed up while I'm still snuggled under the covers. I'm very spoiled!

The energy guy said our thermostat has an AUX light that comes on (green) when it kicks in. Gee. I thought it was a good thing to see the green button light up.

[meierlde]

Just look for a heat pump thermostat, since it appears you have a heat pump. (It is just the a/c running backwards, taking heat from outside to the inside). The 5x only applies if its in the 50s outside, by the time you get to the 20s its less than 2x. (It is harder to get heat out of cold air than warm air). BTW if the outside unit is more than 15 years old I did the audit suggest replacing it? Both on A/C and heating they have gotten a lot more efficient than in the past.

[ERD50]

Quote:

Originally Posted by meierlde The 5x only applies if its in the 50s outside, by the time you get to the 20s its less than 2x.

I'm assuming the 5x means that the resistive heating elements kicked in (like the coils in a toaster or electric stove top). These take a lot more current, they are actually creating heat rather than 'moving' it, like the heat pump does.

-ERD50

[simple girl]

Quote:

Originally Posted by meierlde Just look for a heat pump thermostat, since it appears you have a heat pump. (It is just the a/c running backwards, taking heat from outside to the inside). The 5x only applies if its in the 50s outside, by the time you get to the 20s its less than 2x. (It is harder to get heat out of cold air than warm air). BTW if the outside unit is more than 15 years old I did the audit suggest replacing it? Both on A/C and heating they have gotten a lot more efficient than in the past.

Yes, it's a heat pump. However he said we also have a stage II system - I think he called it a heat strip. It sounds like that kicks in when the heat pump can't get the job done by itself. (The unit is only 5 yrs old, BTW.)

This sounds like what I think we have:

"Considered supplemental or auxiliary heating, a heat pump goes into stage 2 when the air inside the house continues to become cooler even though the heat pump is operating at full capacity. This supplemental heating unit may be operated by gas, electricity, hot water or even oil, and under normal circumstances will go on and off without any adjustment being made to the thermostat. The supplemental heating operates along with the normal heat system and on most heat pump systems the only indication you will have that the second stage has come on is by a small green light glowing on the thermostat panel.

Read more: The Stages of a Heat Pump | eHow.com http://www.ehow.com/list_5976616_stages-heat-pump.html#ixzz1Ig94wO8Q"

There's a big box up in our attic...I think that might be the Stage II heat strip he is talking about. Man, I know, I really do sound clueless writing this, but at least I try to understand these things.

Oh wait, here's a link that seems to describe it perfectly:

http://www.jea.com/about/pub/downloa...Management.pdf

[samclem]

Quote:

Originally Posted by simple girl Yes, it's a heat pump. However he said we also have a stage II system - I think he called it a heat strip. It sounds like that kicks in when the heat pump can't get the job done by itself. (The unit is only 5 yrs old, BTW.)

Yep, "heat strips" = resistive heating. We had an older heat pump and when the light came on indicating the resistive heating was on, it was labelled "EMERGENCY", which isn't far from the truth. As it gets colder and colder outside, the "regular" heat pump struggles to get enough heat from the air, so the heat strips eventually come on so that you don't get cold in the house. If they come on because it's too cold outside, the heat pump has already gotten fairly inefficient, so it's no longer 5X as much energy use (probably more like 2X, as meirdle says). But, if you bump up the requested temp int he house by 3 deg, and if the thermostat interprets that to mean that the heat pump can no longer generate enough heat and turns on the heat strips, then it's quite possible that you'd be paying 5X more for the "faster" heat, for no good reason.

[simple girl]

Quote:

Originally Posted by samclem Yep, "heat strips" = resistive heating. We had an older heat pump and when the light came on indicating the resistive heating was on, it was labelled "EMERGENCY", which isn't far from the truth. As it gets colder and colder outside, the "regular" heat pump struggles to get enough heat from the air, so the heat strips eventually come on so that you don't get cold in the house. If they come on because it's too cold outside, the heat pump has already gotten fairly inefficient, so it's no longer 5X as much energy use (probably more like 2X, as meirdle says). But, if you bump up the requested temp int he house by 3 deg, and if the thermostat interprets that to mean that the heat pump can no longer generate enough heat and turns on the heat strips, then it's quite possible that you'd be paying 5X more for the "faster" heat, for no good reason.

Thanks Samclem - that makes perfect sense.

The other suggestions made and insights provided:

- Suggests not turning the heat at night down more than 5 or 6 degrees below our "comfort zone" daytime temp, b/c trying to "catch up" (ie. warm up) the next day sometimes costs more in the long run
-add polystyrene foam board to the wall inside our attic that only has R13 insulation; plus make sure to add it to the back of the door leading to our walk-in attic (it's hollow-core)
- get an insulated blanket for our water heater (it's in our attic)
- add R-13 to one wall in our basement (it's an unfinished walkout to deck type of basement). Also, states the prior homeowner must have put the insulation in on the ceiling...says since we have a "sealed" basement, we don't need insulation there...plus the insulation was put in backwards (paper facing the basement)...but it won't hurt anything to leave it be.
- $5 air filters are just as good as $15/$20 filters, as long as they are pleated. Need changed every month in winter/summer but only every 3 mo in spring/fall b/c system not running as hard
- our windows aren't great but he didn't think it was worth investing in new windows for the house. (we already put tint film on them) He did suggest we add window stripping to the bottom of our windows
- we don't run the upstairs thermostat in the winter b/c it is warm enough without it (we have two zones). He encouraged us to run the a/c in the summer, though, (even if high at 84/85) to keep humidity controlled.

[samclem]

Unsolicited comments:

Quote:

Originally Posted by simple girl - Suggests not turning the heat at night down more than 5 or 6 degrees below our "comfort zone" daytime temp, b/c trying to "catch up" (ie. warm up) the next day sometimes costs more in the long run

Yes, this makes good sense given your situation. It might not be good advice for someone using gas heat, etc.

Quote:

Originally Posted by simple girl -add polystyrene foam board to the wall inside our attic that only has R13 insulation; plus make sure to add it to the back of the door leading to our walk-in attic (it's hollow-core)

That's a good idea and easy to do. The 2" thick white EPS board (looks like it's made up of a bunch of beads stuck together) is the cheapest stuff and works fine. Glue it up with some adhesive that is compatible with foam. Often the best answer if you need a lot is usually to buy the really BIG tube (28 OZ) and caulking gun (LOCTITE "PowerGrab" works on EPS and is often cheap). If you've got gaps between the sheets and something else (e.g. if you're putting them in stud bays), seal up the gaps with Dow GREAT STUFF foam. GREAT STUFF works well, but it's extremely sticky, so wear gloves and eye protection, and cover your hair. GREAT STUFF will harden up in the straw, so get all the panels up and then do all your GREAT STUFF sealing at one time.

If you've got a door to the attic, be sure it has good weatherstripping. You'll lose way more heat through a small gap than due to lack of insulation on the back of the door.

Quote:

Originally Posted by simple girl - add R-13 to one wall in our basement (it's an unfinished walkout to deck type of basement). Also, states the prior homeowner must have put the insulation in on the ceiling...says since we have a "sealed" basement, we don't need insulation there...plus the insulation was put in backwards (paper facing the basement)...but it won't hurt anything to leave it be.

I'm not quite following this. Do you have any heat registers going to your basement (that is, it "conditioned space")? The R-13 insulation on the basement wall can be foam (it's a better choice than fiberglass batts when things might get wet), but the foam will need to be covered by drywall (the foam is flammable, fire codes and common sense require it be covered with gypsum board if it's in a living area).

Good luck!

[simple girl]

Quote:

Originally Posted by samclem Unsolicited comments:

Much appreciated!

Quote:

Originally Posted by samclem That's a good idea and easy to do. The 2" thick white EPS board (looks like it's made up of a bunch of beads stuck together) is the cheapest stuff and works fine. Often the best answer if you need a lot is usually to buy the really BIG tube (28 OZ) and caulking gun (LOCTITE "PowerGrab" works on EPS and is often cheap). If you've got gaps between the sheets and something else (e.g. if you're putting them in stud bays), seal up the gaps with Dow GREAT STUFF foam. GREAT STUFF works well, but it's extremely sticky, so wear gloves and eye protection, and cover your hair. GREAT STUFF will harden up in the straw, so get all the panels up and then do all your GREAT STUFF sealing at one time.

Thanks so much - very helpful!

Quote:

Originally Posted by samclem If you've got a door to the attic, be sure it has good weatherstripping. You'll lose way more heat through a small gap than due to lack of insulation on the back of the door.

Thanks, and yes, we have fixed the seal around the door for sure already. It definitely was leaking cold air when we moved in.

Quote:

Originally Posted by samclem I'm not quite following this. Do you have any heat registers going to your basement (that is, it "conditioned space")? The R-13 insulation on the basement wall can be foam (it's a better choice than fiberglass batts when things might get wet), but the foam will need to be covered by drywall (the foam is flammable, fire codes and common sense require it be covered with gypsum board if it's in a living area). Good luck!

Yeah, I don't think I explained it very clearly. No, no heat registers to the basement, so it's not heated. However he said it's "sealed" in that there is no ventilation coming through the basement like there is in the attic. He stated that although it gets colder in the basement than the heated part of the house, it shouldn't get as cold as the attic. That is definitely true.

The back wall of the basement is concrete. The two side walls are firewalls (between other townhouses). The front wall of the basement is wood construction with a bunch of big windows and a door leading out to the deck. That's the wall he said needs insulation. I think his point is that if we insulate that wall, the other three are already insulated, and the ceiling doesn't really need insulated then. I think. Not that we are going to change the ceiling - it's waaaayy to high to wanna mess with.

[Arnie]

Quote:

Originally Posted by ERD50 I think there are thermostats designed specifically for this. IIRC, they can be set to be more 'conservative' about kicking in the second stage. Maybe more time delay, or they look at the ramp time or something. -ERD50

Our new furnace has that. Whatever we program it to be in the morning, it will gradually build up to that. Very nice. If we even have a "less-conservative" programmable option, I am not aware of it.

[meierlde]

Quote:

Originally Posted by samclem Yep, "heat strips" = resistive heating. We had an older heat pump and when the light came on indicating the resistive heating was on, it was labelled "EMERGENCY", which isn't far from the truth. As it gets colder and colder outside, the "regular" heat pump struggles to get enough heat from the air, so the heat strips eventually come on so that you don't get cold in the house. If they come on because it's too cold outside, the heat pump has already gotten fairly inefficient, so it's no longer 5X as much energy use (probably more like 2X, as meirdle says). But, if you bump up the requested temp int he house by 3 deg, and if the thermostat interprets that to mean that the heat pump can no longer generate enough heat and turns on the heat strips, then it's quite possible that you'd be paying 5X more for the "faster" heat, for no good reason.

Actually just to provide data on heat pumps I just installed, the coefficient of performance is defined as heat out/electric power in (defined in the same units of course) At 65 f its 5.15 at at 25f it is 3.01 and at 5 it is 2.24, outputs are 65 33.9 kbtu/hr 25f 17.4 kbtu/hr and at 5f 12.0 kbtu/hr. So its clear that at some point because the heat needed to keep the house warm increases with colder temps, why backup resistance heat is needed. So on a mild day you get a factor of 5 over pure electric heat on a day in the 20s a factor of 3 and on a really cold night a factor of 2. BTW the HSPF of these units is 8.5 for comparison purposes.
I thought that providing a detailed explaination of how a heat pump behaves might help understand why the resistance heat is needed.
BTW this is why ground source heat pumps (taking the heat from ground water do so well since below a depth in most places ground water never freezes.

[wallygator69]

Hi,

I have a 2 stage heat pump exactly as described but my 2nd stage doesn't work (ie. Heat Strips don't come on). I wondered why when it was 20 degrees out it took an hour to go from 64 degrees to 70 degrees. But my electric bill has never been more than $200.00. All my neighbors with similar houses paid $350-$400 per month because of the heat strips. I opted not to have them fixed as it has saved me approximately $4000.00 over the past 5 winters. Only downside is if I needed emergency heat (ie 2nd stage) it would not work.

Take Care,

Wally

[travelover]

Quote:

Originally Posted by wallygator69 ........... Only downside is if I needed emergency heat (ie 2nd stage) it would not work.........

True, but you can buy some inexpensive 110 volt heaters to keep around if you ever need them. Pick them up at a garage sale or at the end of season at a big box store.

[simple girl]

Quote:

Originally Posted by wallygator69 Hi, I have a 2 stage heat pump exactly as described but my 2nd stage doesn't work (ie. Heat Strips don't come on). I wondered why when it was 20 degrees out it took an hour to go from 64 degrees to 70 degrees. But my electric bill has never been more than $200.00. All my neighbors with similar houses paid $350-$400 per month because of the heat strips. I opted not to have them fixed as it has saved me approximately $4000.00 over the past 5 winters. Only downside is if I needed emergency heat (ie 2nd stage) it would not work. Take Care, Wally

Ironic that something being broken saved you money!

[Telly]

Quote:

Originally Posted by wallygator69 I have a 2 stage heat pump exactly as described but my 2nd stage doesn't work (ie. Heat Strips don't come on). I wondered why when it was 20 degrees out it took an hour to go from 64 degrees to 70 degrees. But my electric bill has never been more than $200.00. All my neighbors with similar houses paid $350-$400 per month because of the heat strips. I opted not to have them fixed as it has saved me approximately $4000.00 over the past 5 winters. Only downside is if I needed emergency heat (ie 2nd stage) it would not work.

You could have the best of both - Fix the heat strip problem, so you could have emergency heat if needed. Put a switch in series with the wire from the thermostat to the air handler that turns on the strip heaters.
With the switch open, it would act just like your system does today.
With the switch closed, you could turn on the emergency heat switch on the thermostat, and have the strip heaters work.

[meierlde]

Quote:

Originally Posted by Telly You could have the best of both - Fix the heat strip problem, so you could have emergency heat if needed. Put a switch in series with the wire from the thermostat to the air handler that turns on the strip heaters. With the switch open, it would act just like your system does today. With the switch closed, you could turn on the emergency heat switch on the thermostat, and have the strip heaters work.

Or ask the person who fixes the heat strip to change the set up of the thermostat, so that it does not call for aux heat, but you can press the emergency heat selection when desired.

[jazz4cash]

Quote:

Originally Posted by meierlde Actually just to provide data on heat pumps I just installed, the coefficient of performance is defined as heat out/electric power in (defined in the same units of course) At 65 f its 5.15 at at 25f it is 3.01 and at 5 it is 2.24, outputs are 65 33.9 kbtu/hr 25f 17.4 kbtu/hr and at 5f 12.0 kbtu/hr. So its clear that at some point because the heat needed to keep the house warm increases with colder temps, why backup resistance heat is needed. So on a mild day you get a factor of 5 over pure electric heat on a day in the 20s a factor of 3 and on a really cold night a factor of 2. BTW the HSPF of these units is 8.5 for comparison purposes. I thought that providing a detailed explaination of how a heat pump behaves might help understand why the resistance heat is needed. BTW this is why ground source heat pumps (taking the heat from ground water do so well since below a depth in most places ground water never freezes.

The big point that the OP was making is that regardless of the outside temperature, many heat pump thermostats will engage resistive heating ANYTIME the room temp is more than 2 degrees below the setpoint. I learned this the hard way also and we no longer use a setback for our heatpump. Heat pumps take a long time to raise the temperature, so the thermostat engages re$i$tive heating to boo$t performance. Ours has an "AUX Heat" indicator that lights up when the resistive strips are running. I think there are two of these that engage progressively. I know the newer units are better, but ours is about 10 yrs old and we are not likely to get another air source heat pump unless it has a gas backup feature.

[meierlde]

Quote:

Originally Posted by jazz4cash The big point that the OP was making is that regardless of the outside temperature, many heat pump thermostats will engage resistive heating ANYTIME the room temp is more than 2 degrees below the setpoint. I learned this the hard way also and we no longer use a setback for our heatpump. Heat pumps take a long time to raise the temperature, so the thermostat engages re$i$tive heating to boo$t performance. Ours has an "AUX Heat" indicator that lights up when the resistive strips are running. I think there are two of these that engage progressively. I know the newer units are better, but ours is about 10 yrs old and we are not likely to get another air source heat pump unless it has a gas backup feature.

It very much depends on the thermostat and how it is set up the Honeywell series 5000 thermostats have a setting that determines comfort or economy on the use of aux heat.
The comfort setting turns the aux heat on earlier while the economy setting tends to wait a bit longer to see if the heat pump gets the job done alone. I suspect most modern electronic thermostats have this capability.