A sticking point I encountered - the drop in efficiency as the weather gets colder means you need a unit sized to heat your home on the coldest days you expect to encounter. So you need to buy a heat pump that’s larger than you need for 98% of the year just so you don’t freeze that other 2%. In addition to higher cost an oversized unit is less efficient because it’s cycling more.
So this is where “heating strips” or “backup heating” come in, and then I get we’ve come full-circle.
I don’t see how this is “full circle”. In places where it does get that cold, most homes already have a form of heating for the house. Adding on a heat pump or, at least in my case in the Midwest, replacing the central AC unit with a heat pump just means that you’re only kicking that original heating system on a few days out of the year. That’s a massive reduction in use compared to being the only source of heat for half the year.
It’s a problem that new construction homes would need to fix if they don’t want an NG connection at all, but it’s not unsolvable.
I think modern inverter units are not less efficient when oversized. They are able to run at varying levels rather than cycling.
The optimal solution is to add a small heatpump in addition to a gas heating
Those “heating strips” are only used a few weeks every year in my case.
You’d usually run two or more units in a cascade/multiplex when requiring large amounts of power rather than having one giant unit. Means you can turn off one or more units entirely for low heating demand.
Also choosing a unit (or units) that use a speed controlled compressor will limit cycling as they can ramp for the actual load.
But does it more effectively keep houses warm in cold weather, and cool in hot?
Yes. Heat pumps heat homes more effectively than the alternatives down to remarkably low temperatures, and many models also serve as air conditioning - it’s merely a matter of inverting the process.
Heat pumps are most effective in moving heat from where it is abundant to where it isnt. This means they’re best at keeping your house warm in warm weather, and keeping it cool in cool weather.
Then a heat pump won’t do any good. Achieving the right temperature is far more important.
no he said “best”. they still work, just not as efficiently.
Now if electricity was just less than 3x the price of gas, we’d be winning.
Has not been updated for a while, but relevant link…
https://www.energy.gov/eere/buildings/residential-cold-climate-heat-pump-challenge
So, what happens when high winds or a blizzard takes down the power lines
I lived through the 98’ Ice Storm in the Northeast US Didn’t have power for three weeks
Tbf most modern fossile fuel heating systems require power as well to some degree.
I think going forward we will have a much more decentralised power grid, as in people will have batteries to store a significant amount of power which they produce via solar panels on top of their houses. Also many electric cars today can be used as power storage.
Too bad governments are not promoting Household Solar Systems for a decentralized grid
While I am generally in favour of a strong government: Does Politics have to dictate everything?
I’ve got news for you.
Even if the gas lines work, your furnace still needs power to open the fuel lines, ignite the fuel, circulate the inside air through the heat exchanger, and, above all else, do it safely.
You’re screwed either way if you don’t have power.
Sure, you can run a gas fired furnace on batteries far easier and more cheaply than you could with an all electric system (regardless of how it’s generating the heat), but in every case, you need electricity to run the systems.
This is all dancing around the very real fact that we need to upgrade the grid. Between air conditioners, heat pumps, and electric cars, adding to the already increasing demand from so many computers and computerised gadgets that we have today, sucking back so many more kilowatt hours more power per day, per household than ever before. About the only thing that’s going to work when the power shuts off is your toilet.
Thats the rediculous thing. I constantly see people argue about power outages (which realistically aren’t even common in many countries). My parents had a power outage, and couldn’t use their Gas heaters. When I had one, I couldn’t use my instantaneous gas water heater (although, my heat pump based one, can keep water warm for 3 days apparently, so its actually better). My old gas heater actually apparently has been known to burn down houses when there is no power (because the fan stops, and apparently in some circumstance, they overheat)
People don’t realize how dependent many of their gas appliances are on power
People don’t realize how dependent they are on power in general. It runs basically everything, with the exception of your car.
Yet, nearly nobody has any plans for what they’re going to do if the power stops working.
Most households, almost everything is electric or electrically assisted… the only real exceptions I can think of, are your vehicle, barbeque, and water systems (not including hot water). So toilets flush, you can cook on the BBQ, and you can drive away from the collection of wood and bricks you call a home, and go somewhere with electricity… that’s about it.
Battery, generator, or some systems work off the fuel pressure
Batteries or generators could also work for heat pumps, or you could have emergency backup propane heat. Basically the short answer to your concern is “prepare” just like how you handle every other emergency situation like that ever, regardless of what kind of heating system you use.
Also a big part of it is fixing up your insulation. Modern insulation is great, a well insulated house is super cheap/easy to heat.
A heat pump and propane heat seem like a huge waste of money for duplications Plus where do I get the propane after it’s banned
Switching to propane is one safer alternative that is being recommended for people with natural gas lines to their houses, it is less leaky and cleaner burning than the methane stuff. Propane won’t be banned, but it will become more expensive as supplies dwindle.
If you have an air conditioner you already have a heat pump, it just needs to be one that can alternate directions between heating and cooling. Also, backup emergency heat would not need to be nearly as extensive as a full house propane furnace. Or, you could just use a propane emergency generator instead and keep using the heat pump. Propane can be stored long term much more easily than alternatives like gasoline, and while it can be pricier, just having enough for emergencies is not a great cost.
No - a gas electricity generator, powering a heat pump, will use an order of magnitude less gas than if you used the gas directly to heat your home. That’s how efficient heat pumps are.
Home generators are not very efficient, they lose a lot of energy to heat and noise. It’s close to the break even point so depending on your generator and heatpump, you could use more gas than with a modern gas furnace. Even with a theoretical perfect 100% efficient generator, it’s not going to be an order of magnitude less gas because heat pumps are not 1000% more efficient than a gas furnace
Follow the Money for who funds these studies
they do https://www.raponline.org/# feel free to investigate on them.
Unfortunately gas costs a lot less for the same amount of energy. So it’s only going to save you money if you use simple electric heating.
For those of us on gas boilers, the prospect of a system paying for itself (maybe) in 50 years time isn’t overly enticing.
🤖 I’m a bot that provides automatic summaries for articles:
Click here to see the summary
Heat pump uptake is rising in many countries as fossil fuel energy prices have soared following the invasion of Ukraine and as governments seek to reach net zero greenhouse gas emissions.
France, for instance, installs 10 times as many heat pumps as the UK, where many people are unfamiliar with them and doubts about their efficacy have been widely publicised.
The authors said the findings showed that heat pumps were suitable for almost all homes in Europe, including the UK, and should provide policymakers with the impetus to bring in new measures to roll them out as rapidly as possible.
Dr Jan Rosenow, the director of European programmes at the Regulatory Assistance Project and co-author of the report, said: “There has been a campaign spreading false information about heat pumps [including casting doubt on whether they work in cold weather].
The Guardian and the investigative journalism organisation DeSmog recently revealed that lobbyists associated with the gas boiler sector had attempted to delay a key government measure to increase the uptake of heat pumps.
The UK government is consulting on proposals for incentives to households to take up heat pumps, which at about £7,000 or more can cost two or three times as much up front as gas boilers.
Saved 57% of original text.
Apparently it doesn’t work in Germany. Physics work differently here. At least that’s what our corrupt politicians want us to think
I hear that too. Not just politicians, there’s loads of experts lecturing on heating technologies. It’s just too cold in Germany for heat pumps. Doesn’t stop Scandinavia from getting them, granted, but in Germany it’s just too cold. No point. Sorry.
I can’t get an electrician and contractor to come install one (as an AC mainly) inside of 6 months, and I’ve been trying to find one for 6 months.
The heat is actually killing me I can’t sleep and have other health problems. I brought a dual hose unit from the US with me I’m running on a voltage converter and it’s the only thing keeping my apartment livable.
Too cold, too cold…
Germany has corrupt politicians? Say it ain’t so!
/s (all politicians are corrupt)
Actually, there is a noticeable difference between right leaning and left leaning parties, with the former being a lot more corrupt than the latter.
A lot more corrupt, sure, maybe. Not going to get into it too much… but that shouldn’t imply the other parties are not corrupt… just less corrupt. The diet version of corrupt… so to speak.
In this context is a “heat pump” the same thing as an inverter air conditioner?
A split system.
That’s what most of Australia uses and looks like the pic but Ive never heard them called a heat pump.
A split system AC is a heat pump in any context. So is a refrigerator. They’re all the same technology that move energy via a refrigerant’s latent heat by compressing it into a warm part and letting it expand into a cold part.
Cool, thanks. In that case it’s about one month until I can’t live without my heat pumps. They stop my balls from sticking to my leg.
For larger homes with central heating and radiators inverter air conditioners aren’t really a great solution - they are expensive (especially when you don’t have/need an air conditioner in the first place), unsightly and work for more or less just one room. A heat pump is a generic term for a multitude of things, but as a replacement for central heating you’d most likely have just one outdoor unit that spews cold air and inside you’d have a large heat exchanger where you warm up the water for your central heating (and possibly warm water in general for showering and the like).
It’s pretty amazing.
Yeah, for some reason we renamed them to heat pump.
I suppose they can also be used to slowly heat water as well as the air, which is the main difference.
I like “heat pump”. It’s a very nice ELI5 name. It’s a pump for heat. A water pump takes water and forces it to where it wouldn’t go naturally. A heat pump does the same.
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The study isn’t wrong, but it’s also not right, IMO.
This doesn’t seem to mention the cost of the energy, just how “efficient” it is… which, honestly, “efficient” can imply several things, and they don’t seem to clarify what (at least from my first pass of this doc).
The issue is that even if you’re getting 3-4 times as much heating/cooling as you could with something else, per jule of energy potential that is put into the system (in whatever form that is), if your energy cost for that source of power is high, it’s going to lose the financial argument every time.
Sure, a natural gas furnace will consume “more fuel” and produce less effective heat than a heat pump, but if you’re paying 10x the cost for electricity, then you’re still going to end up spending more per degree of heating than with the cheaper fuel.
Where I am, electricity is pretty cheap, but natural gas is tremendously cheaper per jule… so we can actually pay less by using the “inefficient” fuel for our home.
I don’t think the numbers are dramatically different at the end of the day, but this study seems to completely ignore the core issue that most people will be concerned with… which is: “will this save me money?” Which is arguably the more important metric.
It also doesn’t add up if you’re getting twice the heating per joule of input if you can only input a quarter the number of joules as your source is limited.
Where I am, electricity is pretty cheap, but natural gas is tremendously cheaper per jule… so we can actually pay less by using the “inefficient” fuel for our home.
Most of the push towards rapid adoption of heat pumps is happening in Europe, where geopolitical developments (to put it mildly) caused gas prices to spike last winter. The nature of the natural gas logistics means that different continents can have wildly different prices (unlike petroleum, where you can always throw it on a ship and send it from where it’s cheap to where it’s expensive), so a lot of European countries are seeing these debates play out against the backdrop of their own energy markets. Germany passed a law this year that would phase out new gas furnace installations, so that’s why a lot of the debate is happening with a focus on German markets.
Whether (or how quickly) a transition to heat pumps pays for itself in euros will depend a lot on what happens in the future to gas and electricity prices.
if your energy cost for that source of power is high, it’s going to lose the financial argument every time.
How high, is the question. How much more is electricity where you live that heat pumps “lose the financial argument every time”? Where I’m from a kWh of electricity is roughly 2.8-3x that of natural gas, so most modern heat pumps will beat that, some by quite a margin.
If globalpetrolprices.com is to be trusted and Canadian natural gas is 0.063 CAD and electricity is 0.165 CAD you’re very much in the same boat with a 2.6 ratio. Most heat pumps should be able to beat a 2.6 SCOP even in Canada.
So, sure, the study only looks at COPs and not at overall cost, but I think it’s not unreasonable to expect home owners to be able to divide electricity price by gas price and compare it to the SCOP of heat pumps on offer.
Finally someone taking sense.
Asking me to compare my own bills between natural gas and heat pump is insanity, I don’t have both systems installed just for shits and giggles… but it doesn’t seem to stop people from saying I should do that sort of insane thing to really know.
That site sure is interesting, I haven’t dived into the data enough to know how they got the figures they did, or what it represents… but assuming they’re saying that it’s saying that $0.63 worth of natural gas gives you the equivalent thermal output of 1kWh of conventional electric heating (more or less)… which I think it kind of does, since, to the best of my knowledge, electric heating systems are among the most efficient at converting 100% of the energy input to heat output (or as close as we can get to that). As we know heat pumps exceed this because they’re not generating heat, they’re just moving it around.
Also, a blanket statement like “heat pumps should be able to beat 2.6 SCOP, even in Canada” is problematic, since Canada is huge, and some of that landmass is in the Arctic circle. To be fair, 90% of Canada’s population (or something similar to that) is in the southern 10% of the landmass… still. If we’re being detailed, then such blanket statements should be avoided. A good alternative is “for the majority of the population of Canada”, which is wholly accurate.
There’s also other inefficiencies that aren’t being considered and unless we get really deep with the information, that fact is unlikely to change; however, those inefficiencies may make heat pumps even better on paper…
There’s a lot to say about this incredibly complex topic. And that’s not even touching on the nuances of the word “efficiency”… since efficiency relies on specific conditions, and usually is a comparative figure. Eg, the Ford F-350 super duty is an extremely efficient vehicle, when compared to the Ford model T… many decades of innovation will pretty much guarantee that statement is accurate. But comparing the F-350 to, say, a Toyota Prius on MPG alone, then the F-350 seems like a gas guzzling bohemouth, that’s a symbol of gluttony… Wasting so much more fuel, to travel the same distance. Both saying that the 350 is incredibly efficient and also that it’s extremely inefficient, these are both true, depending on context.
There’s too much nuance here that I’m just going to stop talking before I ramble myself into getting cancelled somehow.
but assuming they’re saying that it’s saying that $0.63 worth of natural gas gives you the equivalent thermal output of 1kWh
Correct (although $0.063), and interesting to see you seem unfamiliar with this, this is the standard way of listing energy prices in Europe, it’s not just that site. That site was just my first hit when I looked up Canadian energy prices. It’s the low heat value and it’s determined by the energy in a fuel if not allowed to condense (which is the relevant value for a traditional furnace, if you have a more modern condensing furnace you take the high heat value) and it makes it relatively easy to compare different sources of energy.
Canada is huge, and some of that landmass is in the Arctic circle.
What people never realise is that being far up in arctic climates doesn’t only impair an SCOP. Yeah the lowest temps are very cold, but that means temporarily bad COPs. An SCOP is made up of the whole heating period though, which in colder climates is longer, so in turn you have several months more of the time where heat pumps are extremely viable with temporary COPs above 5 or 6 saving loads of energy. The real problem is if your lowest temps are so low that a heat pump will stop working entirely, in which case you get a hybrid system or just leave your old furnace in as backup, which is even better for your SCOP because you omit the month(s) with the worst COP and only use the heat pump when it’s most viable. Let’s say you live in Tuktoyaktuk and heating period is basically all year, then you have your furnace on for 3-4 months but you’re saving massive amounts of energy with your heat pump in the other 8-9 months of the year.
touching on the nuances of the word “efficiency”
I actually tend to avoid using that term for heat pumps anyway, as it’s not really correct in terms of physics. What makes heat pumps so viable is a coefficient of performance, their actual electrical efficiency isn’t all that good at 50-60%, but it’s also kinda irrelevant. It’s sometimes easier to just call it efficiency, but like you say, once you go into the nitty gritty it falls apart.
I like you.
I agree, there’s a lot more to it than just the argument that was presented. I am also woefully unfamiliar with measurements of energy in common use, and sort of come at things from a more physics mindset. I’m no physics major, but it just makes sense to me that way.
Personally I’m a fan of heat pumps. There’s plenty of reasons not to go that route, but when it comes to electrically driven heating and cooling, you’ll be hard pressed to find a better alternative.
I’m in the camp of going independent with power. Getting solar, a battery system, and converting everything to electric. That’s the plan at least. If my power is free (from solar) then if I lose some efficiency in the conversation, that’s okay, it’s free power either way… though, not “free”… just, I’m not paying per watt (or kWh) I just need to buy the material to make the system go… that’s not free, but day to day operations are. If I’m making sense.
I’m not where I want to be yet, everything is a work in progress for now. I still have several natural gas systems in the house, including the furnace. I can’t afford to do everything all at once. My current plan is to buy and install a grid-tied solar system, with the option of batteries, in the near future. Maybe the next few years. We have a good South (ish) facing roof above our garage which will be ground zero for solar panels. It’s sizeable, so hopefully 20+ kW of solar will fit.
After that’s in, start working on electrification inside, make sure our grid connection is up to par, and start replacing and upgrading our furnace/water heater/whatever with electric counterparts and try to make everything as efficient as possible.
When finances allow, buy a battery system that can power the house for ~24-48h, based on usage, and add it to the solar system. Maybe start with 10-12h worth, and upgrade as we go. I’m thinking of getting the rack-mount LiFePO4 packs, and starting with around 4 (~20kWh), and go up from there. I’m an IT guy, so racks are a go to for me. As finances allow, pick up another pack to bring it to 5, and another, and another, etc, until we hit my goals. The goals are very specific and I have reasons to want 20+ kW of solar, and 2 days of battery backup. Our area supports net metering, so we should be good to start on the plan. It’s going to take decades to get it done.
This is all very off topic, but I figure were so far down this thread and so deep into the bowels of post history that nobody but you and I will be reading it. I felt like sharing my plan; for no other reason than to say it out loud… more or less.
Heat pumps are in my future. So regardless of all other factors, like “efficiency”… that’s what I’ll be doing. Hybrid is definitely an option, though, I’ll probably go with “dual source” (heat pump + electric resistive) for my system if possible. We’re pretty far south in Canada where I am (Niagara region) so I’m ok for the heat pump to provide 100% of my heating for over 99% of the year. We only occasionally get cold spikes into the -30c range for a few days at a time at most… but I’ll get crucified if the inside temp drops too far (the Mrs will see to that). In the interest of electrification, I’m hoping to get a resistive electric heating system for the alternative heat system. It’s not as “efficient” as the heat pump, but when the heat pump won’t work because of the extreme cold, it’s the next best thing IMO.
I want a battery system because I don’t want to be down if the grid goes away, and I want enough battery that we don’t have to rush onto the roof every time it snows, to clear the panels else we need to run on grid power… having some leaway in how much time we have to deal with the problems that might prevent the system from working, will be perfect.
It’s sometimes easier to just call it efficiency, but like you say, once you go into the nitty gritty it falls apart.
It depends. It’s certainly economically and CO2 efficient. Thermodynamically? That’s something for physicists and engineers to worry about, not J. Random Bloke.
leave your old furnace in as backup
I’ve seen plenty of old houses over here in Germany which did have a gas furnance that was somehow under-dimensioned – the idea is that in the real cold days you’d still have the good ole fireplace (or coal oven), as well as not so old houses which still have one because sitting in front of it.
Gets a wee bit more complicated with heat pumps and maximising the efficiency of everything as the fireplace needs to be hooked up to the heat exchanger or there won’t be any hot water and modern units are closed and look rather different, but you still get a window and plenty of infrared radiation.
Then, last but not least, there’s insulation. Especially up in the arctic you should be doing your darnedest to build passive houses. Certainly possible in Kiruna, I’ve heard that the Norwegians are trying on Svalbard.
gas furnance that was somehow under-dimensioned – the idea is that in the real cold days you’d still have the good ole fireplace
Oddly enough I’ve never encountered that in Germany, I only ever see catastrophically oversized furnaces that start cycling in March… Seems to me plumbers never really worry too much about correct dimensioning, they just put the same 20 kW furnace that they know and love to install in every apartment and single family home. For some it will be somewhat adequate, for some it’ll be oversized, who cares, customers never complain when the furnace cycles, but when it’s too cold, you’ve got a problem. Same as they’re never too worried about finding suitable supply water temps. Just set it to 80 and you’re good, it’s the customer who pays horrendous gas bills, not you lmao. That’s also why everyone thinks their Altbau has to have 80°+ supply water when they have never really tried anything lower to see if it maybe suffices. My parents had their oil-furnace on 80C supply for the past 40 years and last winter when everybody was trying to save as much energy as possible they figured out you can set it to 55 as well.
What’s also interesting is that you have to factor in the costs and CO2 emissions of the fuel source and it’s delivery method. A new building code for a county in my area was adopted which requires calculations for energy efficient HVAC systems and also CO2 emissions with those systems. Surprisingly, natural gas has less CO2 emissions associated with it, while electricity is 2.86 times as much. This is because grid electricity is mostly produced by fossil fuels, then needs to be delivered to the site but there are many losses along the way. So even if the all electric equipment is twice as efficient as the equivalent natural gas equipment, it still contributes more CO2 production. This is part of the issue with phasing out natural gas and moving to all electric in its current state. But with that is the push (and requirements) to produce energy on site and shift towards net zero energy for commercial sites, which is definitely better than using grid power from an emissions standpoint.
honestly, “efficient” can imply several things, and they don’t seem to clarify what (at least from my first pass of this doc).
How would you like to define it?
How about this for an analogy - which of these two is more efficient:
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Plant some wheat in your back yard, buy fertilised eggs to hatch into chickens, plant tomatoes and basil, plant an olive to grow a tree, and eventually, years down the track, you can make yourself a bowl of pasta.
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Notice your next door neighbour already cooked some pasta and made more than they can eat. Ask politely and they’ll just give you a serving.
Obviously - the second option is more efficient, and that’s effectively what a heat pump does. They don’t heat up your home, they just take a bit of heat from the air outside and move (pump) it into your home. It’s far far more efficient than creating new heat from scratch with a gas system.
Exactly how much more efficient will depend on the outdoor and indoor air temperature, and on the brand/model of heat pump you buy, and other factors (such as the length of the pipe between the outdoor unit and the indoor unit). You really should ask for specific advice on your home - but in general, a heat pump is extremely efficient.
Where I am, electricity is pretty cheap, but natural gas is tremendously cheaper per jule… so we can actually pay less by using the “inefficient” fuel for our home.
Have you actually looked into it, or are you just making assumptions?
I can tell you that my heat pump, in my house (yours will be different), in my climate, adds about $5 per week to my electricity bill. Is your gas bill less than $5 per week?
Or at least - that’s how much it cost before I had solar panels. Now that I have solar… it uses about 20% of the power typically produced by the solar panels on my roof leaving plenty of excess power that we sell to the grid for about the same amount of money as what we spend buying power overnight. Since we installed solar our entire electricity bill is about $0 (and we use power for a bunch of other stuff, including to cook breakfast and dinner when the sun typically isn’t shining*). We don’t have a large solar system either - in fact, installing solar cost less than installing heat pumps.
(* our solar system comes with instruments and software to measure our consumption - and I can tell you that heating up a family meal with an electric cooktop uses more electricity than heating an entire house with heat pump… because the cooktop is creating heat, and the heat pump is simply moving heat)
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Electric fans are even more efficient, and about as effective.
What???
This is about heating homes in winter, what are you talking about?? Electric fans are more efficient at what?
If you turn the fan up high enough it will blow the heat from outside into the house. Trust me, I’m a scientists.
would be a neat story in 1920
In Germany this will likely still be a controversial take in 2026. Our political right managed to shift this debate into ideology territory and a good chunk of people believe heat pumps are environmentalists’ fever dreams that don’t really work in cold Germany.
It’s still news today because every time heat pumps are mentioned someone will say that ‘they are nice but it’s too cold to use them where I live’.
That’s like the stupidest take, especially for most of Germany. In the worst case you’d supplement the heat pump with electric heat so in the coldest days when it doesn’t work at all (which will be a few days a year at most) you’d get to … checks notes … 1x efficiency, which is only as bad as having regular electric heating which many people have anyway.
No shit
