Electrify Everything

[mspohr]

Induction (electric) ranges are excellent. We upgraded a couple years ago from NG. It equals or outperforms in all areas. Because energy transfer is much higher than NG and electric resistance, one can sear a steak beyond desired.

Other benefits of induction over NG/propane and electric resistance:
-heats much more quickly
-more precise temperature control
-much easier clean up (smooth cooktop gets much less warm; just wipe down; we've had no problems with burnt on or stuck on food; our NG range was a perpetual mess and burnt on stuff that would never come off)
-uses less energy (energy transferred directly to cookware and not to range top; generates much less residual heat)
-safer/lower burn risk (range top significantly less hot as only gets hot from backfeed from directly heated cookware)

Building a new house and it will be all electric: heat pump (hydronic floor heat and hot water), induction range, Tesla... and of course solar PV.
Started cooking with an induction cooktop (small portable unit) to try it out last year. Induction is fantastic! Heats quickly, precise control, no burned on food, etc. Love it.

 

[RubberToe]

I know late is better than never but it's infuriating that we're still building homes with gas lines when that practice should have ended ~20 years ago in most of the country. Heat pumps work great. Unless you live in an area that sees <0F temperatures >10 days a years having a gas line run into your home is insane

I happened to catch an episode of This Old House over the weekend, and am curious how a house that had a lot of recent work done involving a gas heating system would end up getting converted to electric down the road, if ever. The question also addresses what you all think might be the path toward "converting" current gas homes to electric.

The home in question was a mid-century modern in the Northeast somewhere. Not sure what that home was doing there versus say Palm Springs, Ca. but there it was. The utility upgrade was done in 3 separate rooms in the former basement. It looked like they had installed water fed in-floor radiant heat in most of the house, since the HVAC guy showed an entire room full of PVC tubes feeding various zones in each room. Biggest deployment of that I have ever seen, in a single house. Anyway, the entire system including the hot water utilized a "super efficient" gas heater. I wouldn't have given that a second thought previously, but if we are trying to "electrify everything" then that gas fired system will eventually have to be replaced. It's not unusual for homes that last 50+ years to see a conversion (or two) in their "furnace", as you all know.

I wondered if the path forward for homes that use gas will be: 1) replace the current gas with a renewable derived gas that is delivered through the same system, so minimal equipment replacement required, and keeping the gas infrastructure in place for some number of years or 2) electricity becomes so cheap that the super efficient gas furnace is replaced with resistive (?) or some other electric powered system. The question of seasonal storage of electricity could come into play, but I wouldn't think that would be done at the single home level, if at all. That home has got to heating up a lot of water, and I believe (?) that electricity is much less efficient at doing that than gas, cost wise at least for now.

Any thoughts on which of the two might end up happening for this specific house, and for older homes in general in colder climates where gas is currently the predominant heating source?

Here in Pasadena almost all condo complexes have 100% electric already, so the "how to convert gas to electric" part of the transition isn't one of the hurdles. And I think warmer climates that only require primarily A/C will be easier to transition than colder climates.

Any pointers to research or discussions of the topic would also be appreciated.

RT

P.S. Going to post an update shortly on California's effort at hitting 33% renewable in 2020 which was legislated back in 2015.

 

[mspohr]

I happened to catch an episode of This Old House over the weekend, and am curious how a house that had a lot of recent work done involving a gas heating system would end up getting converted to electric down the road, if ever. The question also addresses what you all think might be the path toward "converting" current gas homes to electric.

The home in question was a mid-century modern in the Northeast somewhere. Not sure what that home was doing there versus say Palm Springs, Ca. but there it was. The utility upgrade was done in 3 separate rooms in the former basement. It looked like they had installed water fed in-floor radiant heat in most of the house, since the HVAC guy showed an entire room full of PVC tubes feeding various zones in each room. Biggest deployment of that I have ever seen, in a single house. Anyway, the entire system including the hot water utilized a "super efficient" gas heater. I wouldn't have given that a second thought previously, but if we are trying to "electrify everything" then that gas fired system will eventually have to be replaced. It's not unusual for homes that last 50+ years to see a conversion (or two) in their "furnace", as you all know.

I wondered if the path forward for homes that use gas will be: 1) replace the current gas with a renewable derived gas that is delivered through the same system, so minimal equipment replacement required, and keeping the gas infrastructure in place for some number of years or 2) electricity becomes so cheap that the super efficient gas furnace is replaced with resistive (?) or some other electric powered system. The question of seasonal storage of electricity could come into play, but I wouldn't think that would be done at the single home level, if at all. That home has got to heating up a lot of water, and I believe (?) that electricity is much less efficient at doing that than gas, cost wise at least for now.

Any thoughts on which of the two might end up happening for this specific house, and for older homes in general in colder climates where gas is currently the predominant heating source?

Here in Pasadena almost all condo complexes have 100% electric already, so the "how to convert gas to electric" part of the transition isn't one of the hurdles. And I think warmer climates that only require primarily A/C will be easier to transition than colder climates.

Any pointers to research or discussions of the topic would also be appreciated.

RT

P.S. Going to post an update shortly on California's effort at hitting 33% renewable in 2020 which was legislated back in 2015.

The point is to stop spending money on NG furnaces (new or remodels).
In my current house, I have a hydronic system that had an old NG boiler which I replaced with a heat pump to feed the floor hydronic tubes and DHW. The other half of the house has a newer NG forced air furnace which I will retrofit with a heat pump heat exchanger when it dies (perhaps sooner).
My new house is all electric with hydronic floor heating and hot water fed by a heat pump.
I've been using Chiltrix units which output hot water directly which can be fed into hydronic tubing, a forced air heat exchanger or hot water tank. (These can do A/C also but we don't need A/C here in the mountains.)

It is possible to retrofit NG heating appliances with heat pumps and you also get A/C with the same unit. Heat pumps are about 4x as efficient as electric resistance heat. Not sure how this compares with NG cost. I have lots of solar so my electric energy cost is about zero.

 

[nwdiver]

I happened to catch an episode of This Old House over the weekend, and am curious how a house that had a lot of recent work done involving a gas heating system would end up getting converted to electric down the road, if ever. The question also addresses what you all think might be the path toward "converting" current gas homes to electric.

The home in question was a mid-century modern in the Northeast somewhere. Not sure what that home was doing there versus say Palm Springs, Ca. but there it was. The utility upgrade was done in 3 separate rooms in the former basement. It looked like they had installed water fed in-floor radiant heat in most of the house, since the HVAC guy showed an entire room full of PVC tubes feeding various zones in each room. Biggest deployment of that I have ever seen, in a single house. Anyway, the entire system including the hot water utilized a "super efficient" gas heater. I wouldn't have given that a second thought previously, but if we are trying to "electrify everything" then that gas fired system will eventually have to be replaced. It's not unusual for homes that last 50+ years to see a conversion (or two) in their "furnace", as you all know.

I wondered if the path forward for homes that use gas will be: 1) replace the current gas with a renewable derived gas that is delivered through the same system, so minimal equipment replacement required, and keeping the gas infrastructure in place for some number of years or 2) electricity becomes so cheap that the super efficient gas furnace is replaced with resistive (?) or some other electric powered system. The question of seasonal storage of electricity could come into play, but I wouldn't think that would be done at the single home level, if at all. That home has got to heating up a lot of water, and I believe (?) that electricity is much less efficient at doing that than gas, cost wise at least for now.

Any thoughts on which of the two might end up happening for this specific house, and for older homes in general in colder climates where gas is currently the predominant heating source?

Here in Pasadena almost all condo complexes have 100% electric already, so the "how to convert gas to electric" part of the transition isn't one of the hurdles. And I think warmer climates that only require primarily A/C will be easier to transition than colder climates.

Any pointers to research or discussions of the topic would also be appreciated.

RT

P.S. Going to post an update shortly on California's effort at hitting 33% renewable in 2020 which was legislated back in 2015.

My home was gas when I bought it. The process is pretty straight forward... I replaced my gas furnace with mini-split heat pumps, replaced my water heater with a HPWH and replaced my stove with an electric stove. Then I called my gas company and told them to pack sand.

A 'Super efficient' gas heater is an oxymoron. If you have 30kWh of gas the most heat you can add to the water is 30kWh if it's impossibly efficient. Even my crappy GE Geospring can add ~90kWh of heat water with 30kWh of electricity.

The best use of any type of syngas is long-duration storage. Homes need to be electrified.

Heat pumps that can operate just fine <0F are slowly becoming more prevalent. I think the HVAC industry at least in the US has been a major barrier. I bought a heat pump for my sister and EXPLICITLY told them my objective was to reduce the use of propane as much as possible. Even THEN they set it up to swap to propane at 40F even though the unit operated fine as a heat pump to <25F.

I think it's the anti-learning virus that's infected so much of America. You have 45 y/o HVAC techs that were taught 10SEER is efficient and you use resistant heat to prevent wear on the compressor and that's the way it's going to be until the end of time....

 

[RubberToe]

Coming to a country near you, starting 1-20-21:

https://climatecrisis.house.gov/sites/climatecrisis.house.gov/files/Climate Crisis Action Plan.pdf

 

[vbaker]

I happened to catch an episode of This Old House over the weekend, and am curious how a house that had a lot of recent work done involving a gas heating system would end up getting converted to electric down the road, if ever. The question also addresses what you all think might be the path toward "converting" current gas homes to electric.

The home in question was a mid-century modern in the Northeast somewhere. Not sure what that home was doing there versus say Palm Springs, Ca. but there it was. The utility upgrade was done in 3 separate rooms in the former basement. It looked like they had installed water fed in-floor radiant heat in most of the house, since the HVAC guy showed an entire room full of PVC tubes feeding various zones in each room. Biggest deployment of that I have ever seen, in a single house. Anyway, the entire system including the hot water utilized a "super efficient" gas heater. I wouldn't have given that a second thought previously, but if we are trying to "electrify everything" then that gas fired system will eventually have to be replaced. It's not unusual for homes that last 50+ years to see a conversion (or two) in their "furnace", as you all know.

I wondered if the path forward for homes that use gas will be: 1) replace the current gas with a renewable derived gas that is delivered through the same system, so minimal equipment replacement required, and keeping the gas infrastructure in place for some number of years or 2) electricity becomes so cheap that the super efficient gas furnace is replaced with resistive (?) or some other electric powered system. The question of seasonal storage of electricity could come into play, but I wouldn't think that would be done at the single home level, if at all. That home has got to heating up a lot of water, and I believe (?) that electricity is much less efficient at doing that than gas, cost wise at least for now.

Any thoughts on which of the two might end up happening for this specific house, and for older homes in general in colder climates where gas is currently the predominant heating source?

Here in Pasadena almost all condo complexes have 100% electric already, so the "how to convert gas to electric" part of the transition isn't one of the hurdles. And I think warmer climates that only require primarily A/C will be easier to transition than colder climates.

Any pointers to research or discussions of the topic would also be appreciated.

RT

P.S. Going to post an update shortly on California's effort at hitting 33% renewable in 2020 which was legislated back in 2015.

Mother Earth News ran an article about 10 years ago about a guy in Minnesota that used solar thermal to heat his workshop and home.

www.builditsolar.com, very good plans on a solar water heater that is proven to work.

I did some experiments using the NREL data on my front SE facing porch and was able to verify two very cold winters in a row that solar thermal is indeed the way to go. Solar panels that are satellite quality are still only pushing close to 30% conversion efficiency. Using low-grade low-performance materials you can easily get 65% conversion efficiency in a DIY ~thermal~ application .

I used rolls of 4 mil vinyl window (think Jeep) material and got the porch to 105F, a scientific friend suggested another layer due to the convection losses and I added 2 mil vinyl to reach a max daytime temperature of 135F. A black-body piece of sheet metal was hung behind the vinyl to capture and radiate the heat (leftover metal roofing painted black).

 

[SageBrush]

Heat pumps that can operate just fine <0F are slowly becoming more prevalent. I think the HVAC industry at least in the US has been a major barrier. I bought a heat pump for my sister and EXPLICITLY told them my objective was to reduce the use of propane as much as possible. Even THEN they set it up to swap to propane at 40F even though the unit operated fine as a heat pump to <25F.

What refrigerant does that MrCool heat pump use ?
The video showed 4 kW draw to keep a 1500 s.f. olde home at 70F when it was <0F outside

VERY impressive, although I don't know what the homeowners will do during a colder than usual spell when temps drop to -30F

 

[vbaker]

What refrigerant does that MrCool heat pump use ?
The video showed 4 kW draw to keep a 1500 s.f. olde home at 70F when it was <0F outside

VERY impressive, although I don't know what the homeowners will do during a colder than usual spell when temps drop to -30F

I did some reading on the multi-room conditioners, LG, Mitsubishi etc. Apparently -4F for heat and +118F for cooling, and I think the literature called it inductive heat pump exchangers. You hang it on a wall, and route three pipes and some wires out to the outdoor unit. Most of the work is DIY, and actually all of it could be since the condenser is pre-charged. You just need to buy enough wall units and a condenser with enough ports.

SEER on the cheap one I was considering is 21, EER is 12 (14 is currently max) and the dbA of each of the units is unbelievably low, <55dbA on the indoor units and <65 on the outdoor. My ceiling fan is almost 55dbA (on medium speed)

 

[iPlug]

What refrigerant does that MrCool heat pump use ?...

R410A.

I was wondering if CO2 to get to the heat pump to operate down to that temp, but alas they still did it with R410A.

MRCOOL Universal Series DC Inverter Split System | MRCOOL

 

[SageBrush]

I was wondering if CO2 to get to the heat pump to operate down to that temp, but alas they still did it with R410A.

Thanks for digging up this information. Interesting !
How did they do it ?

 

[RubberToe]

Good CLean Technica article about the cancelled East Coast gas pipeline. Includes a discussion about how heat pumps are part of the reason why the pipeline isn't needed.

Atlantic Coast Pipeline Done In By Humble Heat Pump

 

[nwdiver]

Good CLean Technica article about the cancelled East Coast gas pipeline. Includes a discussion about how heat pumps are part of the reason why the pipeline isn't needed.

Atlantic Coast Pipeline Done In By Humble Heat Pump

I hope people get a little more educated. When I started my previous job we had a weeks-long class on 'Fundamentals'. Basically the company wanted to ensure that all their operators had a basic knowledge base. When we covered building HVAC I'll never forget one of my co-workers saying in an exasperated tone 'how do you pump heat?'; To be fair I was embarrassingly ignorant on the topic until my mid-20s. It's just not something I had experience with. My WAG would be that ~90% of people have no clue what a heat pump is....

 

[SageBrush]

Good CLean Technica article about the cancelled East Coast gas pipeline. Includes a discussion about how heat pumps are part of the reason why the pipeline isn't needed.

Atlantic Coast Pipeline Done In By Humble Heat Pump

I object !!

Nothing humble about a heat pump. They are just amazing devices that rely on magic, and they are improving at a very rapid pace.

 

[nwdiver]

I object !!

Nothing humble about a heat pump. They are just amazing devices that rely on magic, and they are improving at a very rapid pace.

I want a heat pump oven

 

[SageBrush]

My WAG would be that ~90% of people have no clue what a heat pump is....

That should not surprise you; after all, refrigerators are pretty novel.

My 30 year old kids and I were talking about Covid-19 yesterday and I mentioned the problem of A/C dooming a building to recirculated air unless other measures are taken. They were skeptical so by way of explanation I reminded them that typical A/C is a heat pump. That fell flat since they had never heard of heat pumps and had no idea how they worked. That includes my son who has a BSc in physics.

 

[SageBrush]

I live in a high desert climate at 6300 feet. Even now in July the early morning temperatures drop outside to ~ 65F. I thought I would be able to drop my home's temp to close to AM ambient with powered ventilation but I never succeeded. The home air temp would nadir to ~ 72 - 75F and then quickly rise through the rest of the morning, suggesting that the home mass unrelated to radiation had not cooled down to the interior air temperature.

Nowadays I dream of passive ventilation through the night and then use of a heat pump that I run from ~ 6am - 8am off PV. Imagine the COP !!

 

[iPlug]

Good CLean Technica article about the cancelled East Coast gas pipeline. Includes a discussion about how heat pumps are part of the reason why the pipeline isn't needed.

Atlantic Coast Pipeline Done In By Humble Heat Pump

Electric heat pump retrofits on existing buildings are still uncommon in the US, but the trend is growing for new construction. As of 2019 heat pumps accounted for 40% of new single family residential construction and 50% of new multi-family buildings.​

Awesome trend here, had no idea happening that fast.

I live in a high desert climate at 6300 feet. Even now in July the early morning temperatures drop outside to ~ 65F. I thought I would be able to drop my home's temp to close to AM ambient with powered ventilation but I never succeeded. The home air temp would nadir to ~ 72 - 75F and then quickly rise through the rest of the morning, suggesting that the home mass unrelated to radiation had not cooled down to the interior air temperature.

Nowadays I dream of passive ventilation through the night and then use of a heat pump that I run from ~ 6am - 8am off PV. Imagine the COP !!

Do you use a whole house fan?

Similar issues here. We use our whole house fan in the summer evenings when it is cool enough and in the mornings when still too hot at night. The residual thermal mass in the walls and floors can not be close to fully expelled in just a few hours. We can get internal air temps within a degree of outside temps, but like you temps rise faster than desired when windows are then closed and house fan turned off, due to latent house structure heat.

Would love to run the house fan on low through the night, but wife worried about leaving windows open then.

 

[SageBrush]

Do you use a whole house fan?

A couple years ago I bought a monster fan I installed in an upper story bedroom window. It worked well enough to slam the bedroom door shut unless anchored. I never got to AM ambient, and as mentioned there was still too much latent heat.

That fan is gone now, but I have since learned to take advantage of a chimney effect downstairs via an atrium with high open windows. I think my results are about the same as the fan, but a whole lot quieter.

The night time ventilation was almost good enough through June (meaning a peak of ~ 80F by 6 pm) but it is inadequate in July or when the wind that night is poor (and then the house peaks at ~ 85+F.) All in all I'm really only talking about ~ month of cooling. My fantasy is to run a heat pump off PV at ~ 3 kW in the AM at a COP of ~ 10. My daily powered cooling for that month would then calculate out to 60 kWh of heat removal a day for a month. Even if I run the heat pump more it is still very modest. Does 60 kwh heat removal a day via the heat pump sound ballpark, or is a lot more required ?

Through the year we heat a lot more than we cool, so that is a different story.

 

[iPlug]

...Does 60 kwh heat removal a day via the heat pump sound ballpark, or is a lot more required ?...

Seems about right, depending on the size and insulation envelope of your home and other occupant behavior*.

In our home (~2550 sq ft single story, 2002 build) when days are ~90 ºF for several days in a row, we use about 15 kWh of electricity daily to maintain the house at 77 ºF. Our SEER is 20.5, so COP ~4.3. So that would pencil out to ~65 kWh heat removed daily in that scenario. Actual SEER is probable a chunk less than 20.5 as we didn't upgrade to R-8 ducting and a few other things we aspire to get to later.


*in our case, we run the whole house fan for ~2 hours/day in the summer on average on low speed at 230 kW, typically in the morning to get the inside temps down to the upper 60’s ºF bringing inside temps briefly in parity with outside temps

...COP of ~ 10...

That's a really good COP; ductless mini-split units up to this now?

 

[SageBrush]

That's a really good COP; ductless mini-split units up to this now?

WAG + wishful thinking on my part.

Outside air would be ~ 65F, so a temp gradient of ~ 20F