Any experience with a heat pump?

[Maverick3320]

Wisconsin resident. We had solar installed this year and have a (gas) furnace that is nearing replacement time. Does anyone have experience using a heat pump in a cold-weather state? Our house is approximately 3000 sq ft, if it makes a difference. With the solar it would be nice to have an electric heating option. Looking around online it seems that heat pumps are best in "moderate" climates, which I'm not sure Wisconsin is.

Any other unknown unknowns - things I should be aware of?

[J295]

We had a heat pump here in Nebraska that came with the home we purchased. When it came time to replace it we opted to go without a heat pump.

We prefer gas heat over electric heat. Also, gas heat will be less expensive.

[TomatoTomahto]

If you’d consider a ground sourced heat pump rather than an air sourced one, I have installed such near Boston. Not as cold as Wisconsin, but we are comfortable year round. Since we got rid of our oil burner, and bumped up our solar (and batteries), we pay zero for utilities. There are incentives for all kinds of heat pumps, but IME more for ground based.

[walkabout]

Inverter-based heat pumps are more effective heating at lower temperatures than conventional heat pumps. They are also generally more expensive than conventional heat pumps. Mini-split systems are often inverter-based. The Carrier Greenspeed system is an example of a split system (not sure if it is available as a package unit) that is inverter-based. Whether or not one of these heat pumps work well enough for your climate, I can’t say. We live in northern Alabama, which is solidly heat pump country. We have a Carrier Infinity system, which is not inverter-based.

If you are considering a heat pump, you might also consider a hybrid system. That is a heat pump with a backup heat source, like a gas furnace. The heat pump provides cooling during warm weather and heat during cool weather, down to a configurable outdoor temp. After that, the furnace kicks in to provide heat.

Some factors to consider if thinking about a heat pump:
1. Are they at least not unheard of in your area? You don’t want to have a unicorn system that a large percentage of HVAC techs might not be familiar with.
2. Cost. Inverter-based heat pumps will probably be more expensive that a conventional heat pump. Carrier Greenspeed is, generally, the most expensive system Carrier sells.
3. Cost of operation. Depending on your electrical and gas rates, an all-electric system, hybrid system, or AC/furnace will be more cost effective.
4. Complexity. The more complex mechanically, the more likely it is that an expensive repair is in your future. What does that mean? That an expensive repair is likely? Not necessarily. Something is probably more likely to go wrong than on a simpler system, but those percentages are, in reality, probably actually quite small.
5. Quality of environment (indoor). Some people don’t like the heat produced by a heat pump vs by a gas furnace. That probably has to do with difference of effectiveness at lower temps and higher output temps (I think) for gas vs heat. Multi-stage heat pumps and variable speed heat pumps do a great job during cooling season of keeping indoor humidity levels lower, which means increased comfort.

I think Carrier Greenspeed and the like are impressive technology.

People on this forum often recommend the HVAC-talk forum for HVAC information. I also really like the houzz HVAC forum:

https://www.houzz.com/discussions/heati ... nditioning

[atikovi]

The air coming out of a heat pump feels like a draft, more than heat, unless the backup electric heater kicks in causing your electric bill to rise. Even without the heater, the fan and pump run a lot more often than a gas furnace so that uses plenty of power too.

[TomatoTomahto]

The air coming out of a heat pump feels like a draft, more than heat, unless the backup electric heater kicks in causing your electric bill to rise. Even without the heater, the fan and pump run a lot more often than a gas furnace so that uses plenty of power too.

OP has solar, so electricity cost is constrained.

[atikovi]

The air coming out of a heat pump feels like a draft, more than heat, unless the backup electric heater kicks in causing your electric bill to rise. Even without the heater, the fan and pump run a lot more often than a gas furnace so that uses plenty of power too.

OP has solar, so electricity cost is constrained.

Even in Wisconsin with the long nights and subzero temperatures? Is there a battery bank to store the solar?

[TomatoTomahto]

The air coming out of a heat pump feels like a draft, more than heat, unless the backup electric heater kicks in causing your electric bill to rise. Even without the heater, the fan and pump run a lot more often than a gas furnace so that uses plenty of power too.

OP has solar, so electricity cost is constrained.

Even in Wisconsin with the long nights and subzero temperatures? Is there a battery bank to store the solar?

I believe Wisconsin has net metering, so effectively the grid is the battery. I don’t know if OP has a residential battery.

MA has some cold and windy nights also, but not Wisconsin cold.

[Yooper]

My brother-in-law about 75 miles west of me has geothermal and while cool in the summer, I have to agree with Atikovi. In the winter even though the thermostat reads the right temperature, it really does feel like a draft coming out of the vents. So much so that I always dress warmer when I go there. On really cold days/nights they'll fire up the wood stove in the basement or use their propane furnace. Overall though they are saving money and that was their rationale for going the geothermal route.

[Normchad]

My brother-in-law about 75 miles west of me has geothermal and while cool in the summer, I have to agree with Atikovi. In the winter even though the thermostat reads the right temperature, it really does feel like a draft coming out of the vents. So much so that I always dress warmer when I go there. On really cold days/nights they'll fire up the wood stove in the basement or use their propane furnace. Overall though they are saving money and that was their rationale for going the geothermal route.

That’s always been my experience with a heat pump as well. I would not choose to own one again because of this. They will keep you safe and alive, but you will never feel comfortable in the winter.

[Woodshark]

We live in South Carolina. The climate is too warm for oil heat and natural gas is not an option. Almost everyone in our area has a heat pump for both AC and heat. The AC function feels just like a normal central air conditioning system. Coming from a house with gas heat, when in heat mode it feels, well weak. It does warm the house but it takes a lot longer to reach a warmer temp. After 5 years it is the norm, but it does take a while to get used to.

[TomatoTomahto]

My brother-in-law about 75 miles west of me has geothermal and while cool in the summer, I have to agree with Atikovi. In the winter even though the thermostat reads the right temperature, it really does feel like a draft coming out of the vents. So much so that I always dress warmer when I go there. On really cold days/nights they'll fire up the wood stove in the basement or use their propane furnace. Overall though they are saving money and that was their rationale for going the geothermal route.

That’s always been my experience with a heat pump as well. I would not choose to own one again because of this. They will keep you safe and alive, but you will never feel comfortable in the winter.

Perhaps it’s because I have mine set to relatively slow fan speeds for a given heating or cooling setting (to encourage dehumidification in the summer) that it hasn’t bothered me. Our house is also (after two years of upgrades) well insulated and adequately ducted.

Ours, as many modern ones I think, has 9 heating/cooling speeds and 12 fan speeds. For all practical purposes, infinitely variable.

[Maverick3320]

We had a heat pump here in Nebraska that came with the home we purchased. When it came time to replace it we opted to go without a heat pump.

We prefer gas heat over electric heat. Also, gas heat will be less expensive.

Less expensive than free solar? Or do you mean the fixed costs?

[Maverick3320]

The air coming out of a heat pump feels like a draft, more than heat, unless the backup electric heater kicks in causing your electric bill to rise. Even without the heater, the fan and pump run a lot more often than a gas furnace so that uses plenty of power too.

OP has solar, so electricity cost is constrained.

Even in Wisconsin with the long nights and subzero temperatures? Is there a battery bank to store the solar?

I believe Wisconsin has net metering, so effectively the grid is the battery. I don’t know if OP has a residential battery.

MA has some cold and windy nights also, but not Wisconsin cold.

I looked into battery storage but even the lowest cost options would require a 10-12k investment. Apparently Wisconsin (or at least my utility) has regulations against customers going completely off the grid, so I didn't think the battery power would serve much purpose at the current price point.

[HopHead]

I live in eastern NC where winter temps typically don't get down below low 30s. My house is just over 1300 SF and has a conventional heat pump. In the winter, I am COLD (I do keep it at 68 to keep utilities down) and use my ventless fireplace almost daily along with bundling up. Neighbor next door has gas heat and a larger house; when I go over to see her, it feels warmer even though we keep the temp about the same. As previous poster noted, the air coming out of the vents in the winter feels like a draft. I don't think a conventional heat pump would be a good fit for Wisconsin winters.

[grettman]

I live in va. Lived in two places with heat pumps.

I learned one thing: I hate them.

Never ever again.

[softwaregeek]

I live in a temperate climate with solar, heat pump and a small gas furnace that kicks in when outside temps go below 42 degrees, which happens at night a couple of months a year. The solar has a straight ROI but unless you live in a fairly temperate area, gas is probably a better bet. Heat pump efficiency goes down in very cold weather. There is a crossover point at which gas is cheaper.

[4nursebee]

I like these:

https://www.daikinac.com/content/the-da ... rformance/

[TomatoTomahto]

Heat pump efficiency goes down in very cold weather.

That’s the case with air sourced heat pumps. A few feet down, the ground is around 50-60 degrees, year round. That’s why our ground based heat pump keeps us warm and cozy in the winter. And cool in the summer.

ETA: they say that the ground provides 80% of the heating and cooling, electricity provides 20%.

[psychoslowmatic]

I have an air-sourced heat pump combined with an oil forced hot air furnace. I'm in southern NH with a single-zone ranch house. The heat pump keeps me cool in the summer and heats in the shoulder seasons. I did experience what some are complaining about, that the heat pump just blows cold air, but I found bumping up the outside temperature where the oil furnace kicks in fixed it. It was about $1k more than a similar AC unit. I haven't really noticed a difference in my electric bill but I probably use a little less oil than before. Do make sure whatever thermostat you pick will support a fossil fuel + heat pump system, I initially tried a cheaper Honeywell thermostat that it turns out didn't. I settled on an Ecobee.

[ralph124cf]

I have a heat pump with gas back-up on my second story, gas furnace for the ground floor.

Yes, the heat pump only supplies only marginally warmer air, even if it is above your desired temperature set point. The blowing air makes it seem cooler.

The change-over from heat pump to gas is adjustable. When it was first installed, my heating tech set the changeover point at 20 degrees outside air temp. This was uncomfortable. I eventually had him change the changeover point to 35 degrees. This still saved me money during the shoulder season, but was much more comfortable.

Note: One very important advantage of the heat pump is that it does not draw unheated (and dry) air into your living space, which can result in very dry air. If your furnace combustion air intake is located outside of your conditioned envelope, you can disregard this comment.

Ralph

[J295]

We had a heat pump here in Nebraska that came with the home we purchased. When it came time to replace it we opted to go without a heat pump.

We prefer gas heat over electric heat. Also, gas heat will be less expensive.

Less expensive than free solar? Or do you mean the fixed costs?

Good follow up. Meant to indicate that for us the gas cost will be less than our prior electric heat costs. My solar knowledge is zero.

We found other solutions to the problem though. Relocating to warmer climates in the winter time. Ha ha.

[Maverick3320]

We had a heat pump here in Nebraska that came with the home we purchased. When it came time to replace it we opted to go without a heat pump.

We prefer gas heat over electric heat. Also, gas heat will be less expensive.

Less expensive than free solar? Or do you mean the fixed costs?

Good follow up. Meant to indicate that for us the gas cost will be less than our prior electric heat costs. My solar knowledge is zero.

We found other solutions to the problem though. Relocating to warmer climates in the winter time. Ha ha.

"Relocating to warmer climates in the winter time. Ha ha."

This is obviously the best solution

[TheGreyingDuke]

In my role as an Energy Navigator volunteer, I have helped people make decisions about air source heat pumps. A few points to consider:

1) If your current source of fuel is natural gas even solar-generated electricity will be more expensive as a fuel choice; solar is only free at the point of consumption, there is a large investment to be made

2) If your current system is hydronic i.e. produced by a boiler, you will never match the comfort of it with any air system.
http://www.duluthenergydesign.com/Conte ... ra-001.pdf

3) If summer cooling is a big consideration, heat pumps offer a good solution

4) There are CO2-based systems that are becoming available, they offer the option of being matched to a hydronic system because of their higher water temperature. They are available in some parts of the world and in the US in limited numbers.
https://www.denso-am.eu/products/life-e ... heat-pump/

5) If I were building a new,energy-efficient house a heat pump system can be a great solution. Retrofitting them into a house not designed for them work much less well.

6) If I had a small extreme, cold weather backup (think wood stove) maybe a heat pump can be satisfactory, the radiant heat from a wood stove is a good supplement to the convection heat of an air pump.

[Valuethinker]

In my role as an Energy Navigator volunteer, I have helped people make decisions about air source heat pumps. A few points to consider:

1) If your current source of fuel is natural gas even solar-generated electricity will be more expensive as a fuel choice; solar is only free at the point of consumption, there is a large investment to be made

2) If your current system is hydronic i.e. produced by a boiler, you will never match the comfort of it with any air system.
http://www.duluthenergydesign.com/Conte ... ra-001.pdf

3) If summer cooling is a big consideration, heat pumps offer a good solution

4) There are CO2-based systems that are becoming available, they offer the option of being matched to a hydronic system because of their higher water temperature. They are available in some parts of the world and in the US in limited numbers.
https://www.denso-am.eu/products/life-e ... heat-pump/

5) If I were building a new,energy-efficient house a heat pump system can be a great solution. Retrofitting them into a house not designed for them work much less well.

6) If I had a small extreme, cold weather backup (think wood stove) maybe a heat pump can be satisfactory, the radiant heat from a wood stove is a good supplement to the convection heat of an air pump.

Great advice.

Air Source Heat Pumps

The Japanese have engineered these so they will even work in a cold winter climate like Wisconsin- COPS of even 3.0 (1 kwhr electricity => 3 kwhr of heat) down below 32 F. BUT if the system is air-to-air (most US homes) the air will be cooler than out of a natural gas furnace. That's intrinsic to the system - on cold days (below 15F?), your electric bar backup will kick in and provide similar temperatures to a gas furnace (but at a Coefficient of Performance of 1.0 ie 3-4x the cost of natural gas).

If air-to-water ie "hydronic" heating then the rads will feel cold compared to a gas system.

Ground Source/ "Geothermal" Heat Pumps

None of the above really applies re efficiency (semi constant ground temperatures mean COP should always be c 3.0 or better) BUT in general they still run colder in terms of output.

New home/ existing home

HPs (both types) work well if heating "low and slow" is an option. I.e. a house with modern standards of insulation and air tightness. Particularly underfloor (hydronic) heating. The HP is left on at the target temperature all day (and night at a presumably lower one) and the thermal inertia of the house keeps it warm.

If however the house is typical North American and not like that, an HP solution is likely to be uncomfortable relative to natural gas (if available). Natural gas is the "quick and fast" solution.

I had a relation in central southern Ontario (so probably milder than WI, but still -20-30F with windchill on a cold day, rural, exposed ridge position) who had great success with a GSHP. However they had lots of room to lay a trench (thus saving the costs of a deep vertical bore), and propane was the alternative, and they were replacing electric baseboards. They also had a good, airtight, fireplace (with glass doors), and burned a lot of wood. Now they live in town, heat with gas, and miss the (cheaper to run) GSHP+ wood burner -- it was that good.

Conclusion

If you have the option of gas, it's probably the simplest & cheapest solution.

The question of home solar should be separate. I realise that it does depend on your net metering arrangement - too large a system is counter productive if you can't use the extra kwhr or sell them back to the grid.

Addenda

The thermal mass of the house counts. Most modern North American homes don't have a lot of thermal mass-- insulation cuts you off from the thermal mass on the other side. Even if brick, it's usually just a veneer around a wood frame. Again HPs work well if there is thermal mass (such as a concrete floor) that they can slowly heat up, then it gives off that heat over time.

[ncbill]

Live in the south and have a heat pump but never use it in the winter (lock it out in favor of the "backup" natural gas furnace instead)

IMHO, OP should simply replace their existing gas furnace with another gas furnace.

Ground-source heat pumps are the type you want for cold climates but represent a capital investment the OP would likely never recover, given cheap natural gas.

[andypanda]

"Perhaps it’s because I have mine set to relatively slow fan speeds for a given heating or cooling setting (to encourage dehumidification in the summer) that it hasn’t bothered me. Our house is also (after two years of upgrades) well insulated and adequately ducted.

Ours, as many modern ones I think, has 9 heating/cooling speeds and 12 fan speeds. For all practical purposes, infinitely variable."
_____________________

I grew up with heat pumps and have always disliked them, but what you say is true.

I got married in 2018 and miss the gas fired boiler and radiators in the 1916 home I owned for 40 years.

My wife's house had an old single speed heat pump when I moved in and no access to natural gas. I had the entire system replaced with Lennox variable speed units indoors and out. They also replaced the dirty ductboard ducts with large round insulated steel tubes in the crawl space. The air moves slowly and quietly and there is no draft. My wife is still amazed at the significant improvement after living there 25 years. Will we ever recover the silly amount of money I spent? Oh heck no. But it's so comfortable.

[TomatoTomahto]

The air moves slowly and quietly and there is no draft. My wife is still amazed at the significant improvement after living there 25 years. Will we ever recover the silly amount of money I spent? Oh heck no. But it's so comfortable.

Compared to the amount some people pay for First Class flights, where you’re more comfortable for a few hours, you got a bargain.

[jebmke]

My wife's house had an old single speed heat pump when I moved in and no access to natural gas. I had the entire system replaced with Lennox variable speed units indoors and out. They also replaced the dirty ductboard ducts with large round insulated steel tubes in the crawl space. The air moves slowly and quietly and there is no draft. My wife is still amazed at the significant improvement after living there 25 years. Will we ever recover the silly amount of money I spent? Oh heck no. But it's so comfortable.

We replaced an old system with a two-stage (compressor) variable speed fan heat pump. Most of the time it runs at very low speeds and you barely hear it. There is no drafty feeling. The discharge air temp is quite comfortable.

[mkc]

Wisconsin resident. We had solar installed this year and have a (gas) furnace that is nearing replacement time. Does anyone have experience using a heat pump in a cold-weather state?

Here is a good study https://www.aceee.org/sites/default/fil ... /a1602.pdf

In TN we have a dual-fuel system. Heat pump for air conditioning and moderate heating, gas furnace for higher demand heating. Our controller allows us to set the energy costs and the system decides which to run. Mostly heat pump, but first thing in the morning on cold days it will run gas, as it will when the heat pump is in the defrost cycle (and obviously on sub-freezing days).

[Maverick3320]

In my role as an Energy Navigator volunteer, I have helped people make decisions about air source heat pumps. A few points to consider:

1) If your current source of fuel is natural gas even solar-generated electricity will be more expensive as a fuel choice; solar is only free at the point of consumption, there is a large investment to be made

2) If your current system is hydronic i.e. produced by a boiler, you will never match the comfort of it with any air system.
http://www.duluthenergydesign.com/Conte ... ra-001.pdf

3) If summer cooling is a big consideration, heat pumps offer a good solution

4) There are CO2-based systems that are becoming available, they offer the option of being matched to a hydronic system because of their higher water temperature. They are available in some parts of the world and in the US in limited numbers.
https://www.denso-am.eu/products/life-e ... heat-pump/

5) If I were building a new,energy-efficient house a heat pump system can be a great solution. Retrofitting them into a house not designed for them work much less well.

6) If I had a small extreme, cold weather backup (think wood stove) maybe a heat pump can be satisfactory, the radiant heat from a wood stove is a good supplement to the convection heat of an air pump.

Thanks. We bought the house with gas heat and have already invested in solar to wipe out our energy bills during the "shoulder" months. I was looking at a heat pump to soak up some of the potential excess solar created during the winter months when we aren't running A/C but are still paying for gas heat. We can sell excess energy back to the grid but at a very low price.

[mgensler]

In my experience, your heat pump satisfaction rate will depend on how air tight and insulated your house is. Our previous house built in 1983 had no gas on the street and only heat pump. It ran fine down to about 15 degrees. Our current house built in 1960 and has a large addition set on piers without a basement is not very air tight. We installed heat pumps but they only work well to about 32 degrees. Fortunately, we have gas heat as well so we just have the Nest run the furnace below 32.

[bikesandbeers]

Lots of good advice above. Air source heat pump is probably not the best choice where you are regularly below freezing. I am from a mild climate and don't know anything about NEM rules in Wisconsin, but It would seem to be a question of how much excess solar you really have.
Ground source heat pumps are great for efficiency, but not many companies sell/service them.

You best option may be the hybrid heat pump with gas backup. I am currently looking at (air source) heat pumps for my parents who have lots of excess solar. We don't need the gas backup, but seems like the heat pump models with gas are not much more expensive (based on MSRP), that a very high efficiency gas furnace with 2 stage AC and variable-speed blower.

Getting a HERS rating/whole house energy audit makes a lot of sense too, if you don't have a goo idea on how tight your building envelope is.

[4nursebee]

From the link I posted:

Daikin systems have the highest heating capacity at low temperatures, down to -4°F, allowing the individual user to be comfortable with the Daikin system alone, as opposed to turning to alternative heat sources.

[ncbill]

From the link I posted:

Daikin systems have the highest heating capacity at low temperatures, down to -4°F, allowing the individual user to be comfortable with the Daikin system alone, as opposed to turning to alternative heat sources.

And what's the air temp coming out of the vent?

With a traditional heat pump it's typically 105-110F vs. 125F with a gas furnace...much more comfortable.

Again, since the OP has dirt-cheap natural gas available they should have a gas furnace as backup if they choose to install an air-source heat pump, though I wouldn't given their cold climate.

Also keep in mind the dual-compressor air-source heat pumps often recommended for cold climates will be higher maintenance ($$$) than standard single-compressor models.

[TomatoTomahto]

I can’t speak to air sourced heat pumps, but one unanticipated benefit of our ground sourced heat pump is that the air is less dry in winter than it had been with the oil burner.

I have dry skin, and no matter how much moisturizer I put on, my hands were always painfully cracked. No longer.

[csm]

We opted for an air-to-water heat pump when we replaced our oil furnace in Denmark some years ago. Loved the heat pump. It saved us a fortune compared to either oil or natural gas. The air in the house was fresh and clean, it was safe, and we recouped the cost of installation in a few years based on the monthly savings in electricity cost vs either oil or gas. And the house was as warm as we wanted it to be, always comfortable. Also it was very quiet compared to our previous furnace (that was less than ten years old, so not like we replaced an ancient system).

Heat pumps are the most common heating source in Sweden, so I am surprised by the comments about them not being comfortable in cold climates.

[hicabob]

I can’t speak to air sourced heat pumps, but one unanticipated benefit of our ground sourced heat pump is that the air is less dry in winter than it had been with the oil burner.

I have dry skin, and no matter how much moisturizer I put on, my hands were always painfully cracked. No longer.

Same humidity difference with air sourced heatpumps. Furnaces that utilize inside air for combustion dry the air out, a "sealed combustion furnace" which draws combustion air from outside doesn't.

[hicabob]

We opted for an air-to-water heat pump when we replaced our oil furnace in Denmark some years ago. Loved the heat pump. It saved us a fortune compared to either oil or natural gas. The air in the house was fresh and clean, it was safe, and we recouped the cost of installation in a few years based on the monthly savings in electricity cost vs either oil or gas. And the house was as warm as we wanted it to be, always comfortable. Also it was very quiet compared to our previous furnace (that was less than ten years old, so not like we replaced an ancient system).

Heat pumps are the most common heating source in Sweden, so I am surprised by the comments about them not being comfortable in cold climates.

Nordic countries utilize ground sourced heatpumps. These cost a lot more to install since you have to drill deep "wells" or dig a deep trench for the heat exchange tubing which sit in a 55 degree underground environment. Air sourced heatpumps are essentially an air conditioner with a valve to "switch heat direction". Air sourced heatpumps are more efficient for heating for outside temps down to about 55 degrees then ground sourced wins at lower temps. For the cooling mode ground source heatpumps win the efficiency race easily

[Valuethinker]

We opted for an air-to-water heat pump when we replaced our oil furnace in Denmark some years ago. Loved the heat pump. It saved us a fortune compared to either oil or natural gas. The air in the house was fresh and clean, it was safe, and we recouped the cost of installation in a few years based on the monthly savings in electricity cost vs either oil or gas. And the house was as warm as we wanted it to be, always comfortable. Also it was very quiet compared to our previous furnace (that was less than ten years old, so not like we replaced an ancient system).

Heat pumps are the most common heating source in Sweden, so I am surprised by the comments about them not being comfortable in cold climates.

Nordic countries utilize ground sourced heatpumps. These cost a lot more to install since you have to drill deep "wells" or dig a deep trench for the heat exchange tubing which sit in a 55 degree underground environment. Air sourced heatpumps are essentially an air conditioner with a valve to "switch heat direction". Air sourced heatpumps are more efficient for heating for outside temps down to about 55 degrees then ground sourced wins at lower temps. For the cooling mode ground source heatpumps win the efficiency race easily

Good analysis.

A few other data points:

- the natural gas system in Sweden is fragmented. A lot of municipal-owned gas companies. Nothing like 100% of homes have access to gas
- since Swedish gas will come from Russia, mostly, or Norway, it will be at European prices (say 2x American wholesale prices)
- electricity in Sweden (at least) is relatively inexpensive by European standards at the wholesale level (due to the large amount of hydropower, also nuclear stations which were written off in accounting terms a long time ago). Not sure at retail but again I think low by European standards (in USD terms, electricity in UK, Italy etc can be more than 25 cents/ kwhr)

All these factors support heat pumps, but given the extremes of cold, really only GSHP/ geothermal.

- since the 1970s, Sweden has had very high insulation and air tightness standards, progressively tightened (a new British home is in some ways still inferior to a 1970s Swedish standard home). Swedish homes thus are quite warm and well suited to the "low and slow" of heat pumps
- a lot of homes in Scandinavia use centralised district heating systems (which were oil or coal fired, now moved to gas or even large heat pumps) with hot water pipes underground
- wood is a common source of heat in rural Scandinavia at least
- Denmark I know has high retail gas and electricity prices

Japan is the champion of air source heat pumps. Given their houses are quite flammable, it's partly a safety thing I think vs gas flames. Also earthquakes - gas pipes & appliances are not good in an earthquake. Japan does get Midwestern-type cold in winter I believe. The Japanese have engineered the highest efficiencies possible in ASHP.

[Tucker50]

In my prior house, I had a heat pump with a furnace backup. For a time, I also had my heat pump heat my water heater. The latter I don't recommend since it is beyond the skills of most repair folks. I loved my heat pump. With just the furnace I was either hot or cold. The heat pump provided more even temperature but on really cold days the furnace could compensate.

[GlennK]

The coldest winter I ever spent was a winter with a heat pump in NE Ohio. This was 30+ years ago so maybe heat pumps are better. But my first house was in the all electric parade of homes when it was built (I bought it about 12 years after built). It had a heat pump and backup electric furnace. My wife and I never felt comfortable in that home no matter where we set the thermostat. As others stated, the air coming out of with the heat pump was barely above the room temperature.

Anyhow, the next spring I had gas lines run from the street to my house, and installed a gas furnace. We converted the heat pump to air only and it excelled at that. The next winter was comfortable inside. Personally, I would never go with a heat pump again unless I move to Florida (not happening).

[TomatoTomahto]

The coldest winter I ever spent was a winter with a heat pump in NE Ohio. This was 30+ years ago so maybe heat pumps are better.

Uh, yeah, heat pumps are much better than they were 30 years ago. I hear computers and phones are different now also

[Valuethinker]

The coldest winter I ever spent was a winter with a heat pump in NE Ohio. This was 30+ years ago so maybe heat pumps are better.

Uh, yeah, heat pumps are much better than they were 30 years ago. I hear computers and phones are different now also

The laws of thermodynamics still constrain you.

The improvement had been incremental albeit significant.

The main thing is insulation and air tightness of the home. If that is good the Air Source HP works great "low and slow". Keep house warm essentially all the time.

Those of us in poorly insulated homes are used to "high and fast". Come home, slam the heat on, high temperature output. A HP in that configuration is not going to work well.

The efficiency of the HP is inversely related to the gap between input and output temperatures. That's why a GSHP works well in cold climates (and hot ones). The ground is a fairly constant 50 to 55 degrees F, generally.

[wfrobinette]

I live in va. Lived in two places with heat pumps.

I learned one thing: I hate them.

Never ever again.

+1

[wfrobinette]

Wisconsin resident. We had solar installed this year and have a (gas) furnace that is nearing replacement time. Does anyone have experience using a heat pump in a cold-weather state? Our house is approximately 3000 sq ft, if it makes a difference. With the solar it would be nice to have an electric heating option. Looking around online it seems that heat pumps are best in "moderate" climates, which I'm not sure Wisconsin is.

Any other unknown unknowns - things I should be aware of?

How much energy is solar generating in WI in the middle of winter? The days are significantly shorter and the sun is lower on the horizon too. How big of solar system do you have?

Plus WI only see about 180 days are year with sun to begin with.

I'd be talking to some engineering folks at one of the fine UW schools or a very reputable HVAC dealer to calculate things.

[TomatoTomahto]

The main thing is insulation and air tightness of the home. If that is good the Air Source HP works great "low and slow". Keep house warm essentially all the time.

My house is (now) too well insulated, and getting the bedroom cold enough in winter is a problem. Shades of Richard Nixon running the AC and having a fire in the fireplace, I might have to run my GSHP on cooling in the evening. I can open a window in winter proper, but with fall pollen in the air, no thanks.

[caffeperfavore]

Have you looked at geothermal or is it an option? I know people in Illinois, so similar climate, that have them and are happy with them. They seem to be very efficient.