[mithr]

Electricity costs are a big factor in this, imo.

Rates for my northeast town increased by ~25% in 2024 and are going up by another ~10% this year. It's a hard sell to spend a large amount of up-front money (even after rebates, which decreased this year) to convert to a system that will cost you more than you pay today, and may not work as well in cold weather (every heat pump company I talked to suggested keeping my existing gas heating in place and automatically switching to it when it gets cold enough).

I was also told that the electrical grid in my area is having difficulty keeping up with the push towards heat pumps, which increase load exactly on the coldest nights of the year, when you need heating most.

[simmonmt]

Costs are a big thing, sure, but for me it's electrical reliability. For better or worse our heating oil and natural gas supply are both more reliable than our electricity supply. I don't need the heat going out in the dead of winter when some wind storm drops a bunch of branches on power lines.

I'm aware that both my boiler and a natural gas furnace have electric blower motors. It's a lot easier to power them from a generator than it is to have a generator than can power a house worth of heat pumps.

[ssl-3]

You can have both, though. A person doesn't have to make a binary decision of heatpump OR natural gas.

Please remember that traditional aircon is also literally a heat pump. It's perfectly acceptable to have a ducted heat pump and a ducted natural gas furnace both sharing the same ductwork.

In this use, the heat pump and the furnace are just installed series with eachother, with one singular blower motor that is used for both roles. This arrangement is very similar (identical, really) to the layout that combined (heat+aircon) systems have used for many decades.

Power out, or simply very cold outside? Your house still has a natural gas furnace (which can be made work with a fairly small generator), and your rig doesn't require expensive-to-use heat strips for the coldest days either.

[silisili]

My personal anecdote? Don't.

I have a house where the first floor is served by a gas/ac combo unit, and the second floor with a heat pump.

I literally see no advantage to the heat pump and wish I didn't have it. It takes forever to heat and cool, comparitively, and likes to ice over when it gets too cold in the winter while running 24/7 doing nothing. The emergency heat eventually kicks in and fixes it, so I'm considering just running emergency heat all winter.

[rainsford]

The fact that your heat pump setup is also taking longer to cool suggests there's something fundamentally different between the setup on your different floors, not that there is something bad with heat pumps in general.

A heat pump in cooling mode works exactly like an AC unit, because that's exactly what it is. So if your AC unit on the first floor cools more quickly than you AC unit (i.e. heat pump) on your second floor, it's because A) your floors are different sizes or insulated differently or something else is different about their construction, B) your units are sized differently, or C) your heat pump has some mechanical problem. But the fact that it's a heat pump should make no difference to its cooling performance.

[owenthejumper]

Sounds like you have one of two problems: 1) you are changing the temperature too often. Set it and forget it. 2) you have a refrigerant leak

[Loughla]

Our heat pump for HVAC is awesome.

Until it gets under 30. Then you can watch the power meter crank when auxiliary heat kicks on. And we only keep it 65 in the house in the winter.

Luckily I live in the upper Midwest, so it's only that cold for like 4 months. . . Pretty cool. P.r.e.t.t.y. cool

[notyourwork]

Some heat pumps are rated for much lower temps.

[kragen]

They can work at lower temperatures, but they do need the auxiliary heat to deice the outside coils.

[srjek]

It's my understanding that nowadays most heat pumps have a defrost cycle where they automatically run in reverse for a bit with some or all fans off

[sgerenser]

When it’s running in reverse then it’s acting as an air conditioner blowing cold air into the house. So usually the heat strips are used then to reheat the air and prevent it from blowing cold air in the middle of winter. Not strictly necessary but most people demand it.

[kragen]

I think that may be how it works, yeah.

[eldaisfish]

auxiliary heat is a separate heat source for the indoors.

Most cold climate heat pumps run a defrost cycle to melt ice off the outdoor unit. that's different from auxiliary heat.

[kragen]

I see!

[ip26]

the aux heat comes in because their output is a multiplier. At 30F, perhaps they produce 4x the heat as the electricity put in. At 0F, perhaps they produce 1.8x the heat. This means the output declines with temperature, until eventually they don't produce enough heat to hold temperature. Enter aux heat.

Cold weather heat pumps help because they stay above 1x for longer, but you also wind up needing to oversize a bit.

[kragen]

Thank you for explaining!

[potato3732842]

>Rates for my northeast town increased by ~25% in 2024 and are going up by another ~10% this year.

Don't forget that those costs are going up in large part because heat pump subsidies are being rolled into electricity prices.

Imagine being a ~$100k HHI household and paying $300+/mo for electricity so that $200+k HHI doctor/lawyer/HN households can have subsidized heat pumps and our sleazy contractors, and the dealers, and everyone else upstream) can over-charge us for the privilege (thereby getting their cut of the subsidy).

It's a miracle we haven't all caught hot lead yet.

[VWWHFSfQ]

A heat pump just makes no sense whatsoever for me in my northeast town. The electric bill alone would outpace the old propane bill, not to mention installation.

And it won't even work during some of the coldest winter weeks when you _really_ need it to work.

Maybe I would consider it if I was in, like, Nevada or somewhere.

[doctorhandshake]

The notion that heat pumps don’t work at low temperatures hasn’t been true for years. I think you may be surprised to find that just about any heat pump you look at has good efficiency down to very low temperatures.

[crgwbr]

That’s true, but still doesn’t always make heat pumps the most cost effective choice to operate. For example, last winter I paid an average of $0.24/kWh for electricity vs $0.05/kWh for natural gas. Even if a heat pump had a perfect 4.0 COP all winter, gas would be ~15% cheaper. Electricity prices really need to come down before it will be viable for everyone.

[SigmundA]

This varies quite a bit based on location for instance here in Florida natural gas is $0.13/kWh while electricity is about $0.12/kWh, also where I live there is no piped NG so it would be propane delivered to a storage tank which is even more expensive.

Also the winters are mild here so basically everyone has either a heat pump or the further south you go it's just heat strips because heat is rarely used so not worth the cost.

So any kind of blanket statement about heat pumps vs gas heat would be folly, but due to improvements in cold weather heat pumps and solar power are allowing them to make much more sense in more places.

There are many advantages to decoupling fuel combustion from its energy use, burning NG at a power plant relatively efficiently with much better emission controls, then distributing on electric grid for use more than just heating, while allowing the home to heat from many different energy sources and allow for grid down backup as well.

https://www.eia.gov/dnav/ng/ng_pri_sum_a_EPG0_PRS_DMcf_m.htm

https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

[cycomanic]

Does your 0.05/kWh include the distribution costs? The thing to do once you go to heating with gas is to just switch completely to electricity and turn off gas. In my experience (admittedly not in the US, but several other countries) distribution cost often more than double the $/kWh for natural gas (especially if you only heat part of the year).

[doctorhandshake]

Yeah. Sadly the trend does not seem to be heading that direction what with the current admin’s … policies and the whole … AI … thing.

[etimberg]

Not to mention, lots of places have time of use electricity pricing which makes it even worse. This is the problem with running my heatpump when its cold, some of the coldest times (right before dawn) coincide with peak time-of-use prices

[eldaisfish]

where do you live that the highest electricity prices are before dawn?

[kragen]

Get solar.

[crgwbr]

I’ve tried. For it to be at all viable on my property, I’d need to cut down a bunch of trees. I’d rather keep the trees and pay someone else with solar panels.

[kragen]

That makes sense. Is that legal?

[sokoloff]

They have good heat output down to very low temperatures, but not good efficiency.

The CoP is often around 2.0 at those very low temps, though (and of course the heat energy demanded is higher).

[Loughla]

Define low temperatures.

Mine struggles if it gets below 30, and might as well not exist below 10. They're not great at low temps.

[throw0101a]

> Mine struggles if it gets below 30, and might as well not exist below 10. They're not great at low temps.

What percentage of the (US) population gets temperatures like that? That's generally mostly IECC Zone 7 (though cold snaps in Zone 6) can happen:

* https://basc.pnnl.gov/images/iecc-climate-zone-map

ASHRAE—an HVAC organization—has data on the coldest and hottest days for areas so that you can design things for the coldest or hottest 1% of the year (4 hottest/coldest days):

* https://ashrae-meteo.info/v2.0/

I think that if you have an older, leaky/ier, less-insulated house you may need to 'brute force' heating your (probably older) domicile. But if you have a <4 ACH@50 air tightness, and reasonable insulation levels, a good portion of the US population could make do with a heat pump.

Mitsubishi publishes data were they have 100% heating capacity at -15C, which some models being 100% at -20C and -23C:

* https://www.mitsubishielectric.ca/en/hvac/home-owners/zuba

At -25C they have 80% capacity:

* https://www.mitsair.com/wp-content/uploads/2024/10/MEM-20240...

[whateveracct]

> What percentage of the (US) population gets temperatures like that? That's generally mostly IECC Zone 7 (though cold snaps in Zone 6) can happen:

A lot? e.g. Chicago gets it every year

[throw0101c]

>>> Mine struggles if it gets below 30, and might as well not exist below 10. They're not great at low temps.

>> > What percentage of the (US) population gets temperatures like that? That's generally mostly IECC Zone 7 (though cold snaps in Zone 6) can happen:

> A lot? e.g. Chicago gets it every year

[citation needed]

Per historical weather data:

https://ashrae-meteo.info/v2.0/index.php?lat=41.960&lng=-87....

It is warmer than -16C/3F at Chicago (O'Hare) for 99% of the time (i.e., except for 4 days a year), and warmer than -18.7C/-2F for 99.6% of the time (2 days).

ASHRAE are the folks that publish the heating/cooling standards that are used in building codes for estimate heating/cooling equipment capacities (Manual J) and selecting the right equipment (Manual S).

Here's a PDF with a lot of locations in the US and CA (and other countries further down), and if you look under the "Heating DB" column, you'll find very few US locations that have -30F under the 99% (or even 99.6%) sub-columns:

* https://www.captiveaire.com/catalogcontent/fans/sup_mpu/doc/...

So unless you're in AK, MN, or ND, long runs of temperatures colder than -20F/-30C don't happen too often. Of course if you have a leaky house with little insulation, you're throwing money out the window/door, so the first consideration for a good ROI is better air sealing and insulation.

[lotsofpulp]

So gas hash higher reliability and is cheap for the times you need heat the most, whereas heat pumps might not work and are not cheap at the times you need them the most?

I’ve had a gas furnace keep me and the water heated multiple times in a cold weather power outage.

[throw0101a]

> So gas hash higher reliability and is cheap for the times you need heat the most, whereas heat pumps might not work and are not cheap at the times you need them the most?

The major manufacturers have systems that will use the heat pump when the temperatures are not 'crazy', and kick in fossil at a certain point:

* https://www.trane.com/residential/en/resources/glossary/dual...

* https://www.carrier.com/residential/en/ca/homeowner-resource...

* https://www.lennox.com/residential/buyers-guide/guide-to-hva...

Depending on the cost of power and fossil fuels, you can program it to switch over once the COP becomes too low to justify running up kWh on your meter.

But whereas in the past heat pumps would have their COP drop around 40F/5C, modern systems can be fairly efficient at much lower temperature nowadays:

* https://neep.org/heating-electrification/ccashp-specificatio...

You have heat pumps running in Alaska:

* https://www.adn.com/business-economy/energy/2024/09/01/energ...

* https://alaskarenewableenergy.org/wp-content/uploads/2024/10...

[tatersolid]

How did you run the fans on your gas furnace without electric power?

If you have a backup generator, is it too small for your AC in the summer?

[tzs]

That's one of the older style units. Starting in 2007 when Mitsubishi introduced their "Hyper-Heating Inverter" heat pumps, and continuing with Fujitsu and Daikin following with similar technology in the 2010-12 timeframe, and others a few years later, heat pumps got way better in the cold.

Mitsubishi's maintain 200%+ efficiency down to -4℉ (-20℃) and 150% down to -22℉ (-30℃) [1]. Only a few towns in the continental US get below that, and even those aren't going to get cold enough long enough to make it worth it an an all electric home to switch to your emergency electrical resistance heating.

Their capacity doesn't start dropping until you get down to 23℉ (-5℃), dropping to 76% at -13℉ (-25℃).

[1] https://www.coolingpost.com/world-news/study-proves-heat-pum...

[doctorhandshake]

I’m not sure what yours is but it doesn’t sound appropriate to your application.

Mitsubishi hyper heat is indicative of a contemporary inverter design - 100% efficiency to -5f: https://www.mitsubishicomfort.com/articles/mythbusters-heat-...

[sokoloff]

100% efficiency is terrible for a heat pump. Electric resistance heat is 100% efficient.

[doctorhandshake]

I should have said 100% performance. COP is typically 3-4:1 with mitsu

[crazygringo]

I've got one about 8 years old, and it does just fine down to 0°F (it hasn't gotten colder than that here). It doesn't even have any kind of auxiliary heat.

It's fine. The only difference when it's super-cold is that the air coming out of it isn't as warm, so the heating cycle stays on for a longer proportion of the time. But it keeps it 70°F inside no problem at all.

[corbet]

My heat pump, in Colorado, kept the house warm at -18°F last winter. Without firing up the backup resistance heating strip. I think it works.

(It is more expensive to operate than the natural-gas furnace was, though).

[skywhopper]

Insulation matters as well and I’m guessing your Colorado house is far newer and better sealed than most New England homes.

[cycomanic]

I don't know what sort of heat pump systems are common in the US, but Sweden (and AFAIK Norway and Finland as well), are probably >%80 heat pump for single family homes (most apartments are community heating at least in the larger cities). So it's absolutely now problem to run a heat pump even if it is very cold outside, but if you want to improve efficiency in areas that are super cold you can drill into the ground for a heat sink (those are called Bergvärme in Sweden).

Regarding cost, in most of the countries I've lived in a large fraction of the cost in the gas bill was the distribution cost. So once you switch to a heat pump, you also switch to electric cooking and even if heating with electricity would be significantly more expensive you would still win. Is that different in the US?

[DavidPeiffer]

It varies significantly by locale. I've seen people post online about how it made little sense to keep just one gas appliance because of significant savings. I'm in Iowa, which typically heats on natural gas in urban areas. I have a natural gas central furnace and water heater. My clothes dryer is electric, and I have a 3 head heat pump which I use for comfort in a couple rooms. The house is an early 2000's standard builder-grade home.

For September, $12.31 of my $27.01 gas bill was variable based on my consumption.

In December, $84.82 out of my $99.65 total was consumption driven.

I've run numbers on whether it'd make financial sense to go electric for heating, and the break even point is in the 30-40 degree vicinity. With temperatures 20 and under a healthy chunk of the year, unfortunately the added expense doesn't make financial sense.

[yxhuvud]

It works just fine during winters if you do it properly and couple them with ducts that are a couple of hundred meters deep.

[orev]

Heat pumps are just air conditioners in reverse. They use the same amount of electricity whether heating or cooling. While many people have air conditioners, and grids seem to be able to handle them in the summer, an assertion that the grid can’t handle them in the winter is doubtful. Plus there are fewer people using them in the winter (just because fewer are installed). Most people in the NE heat with oil, gas, or wood, so that would reduce the electric load (compared to summer) even further.

There would be an increase only if people were supplementing the heat pump with electric heat, which to be fair is a possibility.

There’s a lot of misinformation about heat pumps, especially by HVAC people who don’t have a lot of experience with them, so they tend to recommend what they’re more familiar with.

But yes, understanding the electricity cost is essential when considering one.

[eldaisfish]

> They use the same amount of electricity whether heating or cooling

This is completely wrong. The amount of power depends on the temperature delta. When cooling, you are typically not cooling your home to 30 degrees Celsius below the outdoor temperature. However, when heating, you are typically heating your home to around 20 degrees above outdoor temperature. Heating consumes more power than cooling.

[ssl-3]

It is approximately correct as long as the temperature deltas are approximately the same for heating vs cooling.

(And as long as we're dispelling generalizations: Those deltas do vary wildly based on local climate, such that they're impossible to generalize and typify.

For instance: The city of Saint Paul, Minnesota [USA] has a very different climate compared to the city of São Paulo in Brazil, with accordingly-different heating/cooling deltas.

https://weatherspark.com/h/y/10422/2025/Historical-Weather-d...

https://weatherspark.com/h/y/30268/2024/Historical-Weather-d... )

[eldaisfish]

Well, in that case, you don’t need a heat pump. You need a sweater and an AC.

The real advantage of heat pumps is in displacing high cost fuels.

[goalieca]

I would be curious to know the difference. In summer you might find 30c outside and inside 20c so a difference of 10c. In winter it can reach -30c and inside is 20c. This is 5x more!

[gardenhedge]

I have a heat pump, along with hvac. It only produces heat. Is it possible to get it to produce cooling too or is that an entirely different system?

[orev]

I’m not an expert, and it would depend on the system you have anyway, but AFAIK the main differentiator between a cooling air conditioner and a heat pump is a “reversing valve”. You may simply need to change the mode to reverse it, then you get cooling. From what I understand, it would be unusual for it only to work in heat mode.