Oxford study proves heat pumps triumph over fossil fuels in the cold::Published Monday in the scientific journal Joule, the research found that heat pumps are two to three times more efficient than their oil and gas counterparts, specifically in temperatures ranging from 10 C to -20 C.
The Oxford study is really good. But I can’t say the same about this article.
A COP of ~2 is not great for a heat pump, calling this a triumph is really weird. But from a journalist saying that a COP above 1 means the heat pump “creates energy”, I am not sure I should have expected more.
But what’s great is that this COP of 2, while bad, is not catastrophic. That’s still in territory where gas boilers are more cost efficient that a heat pump, but unless you are living in a place that is consistently under -10C for several months, then a heat pump has overall lower running costs than a gas boiler. And you are starting to hit pretty northern territories with this.
What’s important is also to be able to store heat during the day so that the heat pump runs at its most efficient time. But that can unfortunately coincide with the higher consumption time, so the timing needs to be adjusted properly to avoid using it during consumption peaks.
a journalist saying that a COP above 1 means the heat pump “creates energy”
But what’s great is that this COP of 2, while bad, is not catastrophic. That’s still in territory where gas boilers are more cost efficient that a heat pump, but unless you are living in a place that is consistently under -10C for several months, then a heat pump has overall lower running costs than a gas boiler. And you are starting to hit pretty northern territories with this.
I actually have a hybrid furnace/heat pump system, and I live in southern Ontario, Canada. The furnace is the auxiliary heat source and it only kicks in when the outdoor temp is below -6C. I’ve only had this system through one winter so far, but I think I could count the number of days the furnace ran without running out of fingers. My electricity bill went up some of course, but my winter gas bill went down a lot.
Edit to add: I wasn’t shopping for a hybrid system in particular, but I got this upgrade through the Canada Greener Homes Grant and there were limitations on which units qualified for rebates. For my install (forced-air with existing duct-work), the hybrid systems were the ones that qualified.
I’m a 4th year AC/R mechanic born and raise in Southern Ontario, currently in BC.
You mebtioned your hydro was up but gas was down. Out of curiosity, can you tell me how your total cost of heating changed before/after your first winter with your heatpump? Did you end up saving money?
Was there any specifig brand/seer rating restriction with the GHGrant? I just applied and will be going this route, but I don’t want to be paying $15000 for a specific brand or something if I can get similiar equipment that might not be on a list.
Was there any specifig brand/seer rating restriction with the GHGrant?
It’s more complicated than that. The major components of the system all have to be qualified for the rebate, down to the component model numbers. There’s a lookup tool to see which model numbers qualify. For a hybrid setup like mine, there are three parts:
- Outside model number: this is the actual heat pump component that gets installed outside
- Inside model number: this is the condenser coil that gets installed on top of the furnace
- Furnace model number: this is the model number of the furnace itself
A ductless system would only have two part numbers involved, the outside heat pump unit and the inside wall unit (though a ductless install can have multiple inside units in multiple rooms). No furnace for a ductless system of course. Edit to add: and all of the major components you get have to be certified with each other by the GH program. They don’t want you mixing and matching.
Every HVAC company I talked to was pretty knowledgeable about the GH program, so if you tell them you’re an applicant then they should put together a quote that qualifies. Multiple HVAC reps advised me to make sure that all rebate-covered part numbers were listed clearly on the invoice. Apparently if that info is missing it can derail the rebate until the invoice is updated with full info.
That’s a useful tool, thanks for linking that. How much did your hybrid system end up costing?
The total install was $12k. I also did another 1k in retrofits under the Greener Homes program, but I did the Greener Homes loan as well. I had to outlay the $13k up front, but then I got all of that back in a 10-year, 0% interest loan, plus $5600 in rebates on top ($5k for the heat pump, $600 for the furnace). The loan processing company debits my account $110 a month, which is low enough that it doesn’t really sting.
I debated doing solar as well, since the Greener Homes loan goes up to $40k. Solar would gave easily soaked up the remaining $25k available in the loan. My roof isn’t ideal for solar though, and I didn’t want to triple the loan’s monthly payments for a solar install that wouldn’t have paid for itself over time.
TY. I’m considering solar as I picked up 2 pallets of panels for our farm, and I don’t need all of them there. I assume there’s all sort of permit issues in the city for that though, so I might just skip it.
Heat pumps are A/C in reverse. It makes total sense instead of using fire to heat air.
brb putting in my window unit from the outside
You’d need to collect the condensate, but that would actually work quite well.
You think you are being a smartass but that’s exactly what heat pumps do. The only functionality difference between an AC unit and a heat pump is a reversing valve.
But without a reversing valve you could put your AC unit in backwards and heat your house in the winter.
The whole premise of an AC unit is to take the heat from inside the house and put it outside, leaving you with cooler air inside.
So in the winter a heat pump simply reverses the flow of the freon and moves the heat from outside to inside. Yes. You are “cooling the whole neighborhood” when you run a heat pump.
I wish it was standard to be able to do both. My heat pump is unreal efficient and cheap and great but I’d love a cool breeze every now and then.
It definitely can. If yours can’t then it’s likely just the thermostat wired wrong.
It’s underfloor heating, the units that do both are more expensive so there must be something different.
Ah yeah that’s a different story then. However I’ve never heard of in-floor cooling before. I wonder how effective it would be since heat rises? I think you’d just have a cool floor and hot muggy air. Also the floor would condense water constantly so your floor would be slippery and if you have carpet it would be wet / damp constantly.
WELL FUCKING OBVI-
Oh right, I forgot some people are really pulling for this fossil fuel think to pull through.
They’re only two to three times more efficient if they aren’t frozen solid. Don’t know how it works in Canada, but my mini-split heat pump can’t handle a week of 10F let alone -20 C - sure it will put out some heat, but it absolutely needs to be supplemented with my wood stove. And I live in the South. Maybe there’s some new high tech heat pumps that cost a fortune and don’t freeze over in the insane temps of the great white north? EDIT: hey, folks, how about actually responding instead of downvoting me? If I don’t have a clue, please enlighten me. Fuckers.
Your mini-split isn’t designed to function as a heat pump at low temperature.
In places like Sweden, they also use heatpumps that are designed for those conditions.
In other news, don’t drive in a Swedish winter with summer tires.
Excellent. Now I know that there are different classes of heat pump. Mine is not for prolonged crazy-low temps, others are. Thank you.
Indeed, but yours is probably cheaper and more effective at cooling when it’s hot and humid out.
For people up north, they will buy a “cold climate air source heat pump”. In temperate regions, an “air source heat pump” will suffice, while down south you will buy an “A/C with a heating mode” (also called reversible A/C).
And it’s not just about whether the coils can defrost. The whole machinery and refrigerant are different to optimize under those conditions. A cold climate heat pump has a setup that is more similar to a freezer than it is to an A/C.
Sorry about the downvotes. People need to re-learn internet etiquette.
This is the most informative answer yet. Thanks.
Thanks for spreading correct knowledge, as someone who works for a manufacturer of heat pumps it’s refreshing
I have never seen so many winter tires, and studded winter tires, as I did on my trip to Sweden last winter.
I think they are mandatory there.
Theres different technology but there are some that can function to -32° F and they often have a feature that allows them to detect when theyre frozen up and defrost and then automatically switch back to heating
Mine has a defrost cycle but it doesn’t work very well. But then again, it’s use case is primarily AC - it only gets frigid temps in my area every couple years. EDIT: yes, downvote me for stating my own personal experience, asshats.
Many parts of Canada will regularly see colder than -40F, so I can sympathize easily with a view that solely relying on them might not be safe in that environment.
Tbf, most Canadians don’t live in those areas. Places like Toronto/Montreal/Vancouver rarely get that cold.
Edmonton Saskatoon Regina Winnipeg
As a Canadian who doesn’t live in the GTA it drives me nuts when people dismiss the rest of Canada as some kind of statistical outlier undeserving of acknowledgement.
Which would account for 5-10% of the Canadian population. Just the three metros I mentioned would account for 35% of Canadians. The record low for the coldest of those cities (Montreal) is -36F, but the average low in January is 7F.
70% of Canadians live south of the 49th parallel (the northernmost point of the Continental US) and 90% of Canadians live within 100 miles of the US border.
Why is it such a controversial thought to merely include and acknowledge the rest of Canada, rather than discounting them outright?
In case you’re wondering here the divide comes from: it’s this, and it’s you.
All Canadians matter, every Canadian experience is valid, and no Canadian is any less of a Canadian than any other. Erasure of Canadian experience outside of the GTA is an elitist and divisive attitude and serves ONLY to create friction where there need be none.
As soon as you erase a group from the whole, it’s INEVITABLE that they’ll seek to find their own independent identity. Considering your proximity to Quebec this shouldn’t be a foreign concept. Just feel free to extend the inclusive attitude west as well as east. It costs nothing to be inclusive of your fellow countrymen.
Because your comment suggests that heat pumps can’t work in Canada. It’s like an American dismissing heat pumps because Alaska is part of the US. For at least 70% (if not more like 90%) of Canadians, heat pumps work just fine. Obviously, if you are in the part of Canada that gets consistently below -40 degrees, don’t get a heat pump.
Also, I’m not from Toronto or Canadian so I’m not sure all that talk about elitism applies to me. I’m from a small city in the US where I experience weather similar to most Canadians.
Yes, there are cold weather heat pumps that can thaw the coils to keep operating. There is a point where they just can’t continue to operate.
When I design a heat pump system in cold climates, I always include a secondary hear source that kicks in if the heat pump gets overwhelmed. Might be a gas section in a furnace. Might be an electric heater in a fan coil. Might be electric baseboards or wall heaters.
Yes, most installations do require a backup heat source in the event outside temperature is too low for optimal heat pump usage. On my ecobee thermostat, you can set what this temperature threshold is (i.e. 20F) and then if the outside temperature falls below this value, the heat pump is stopped and the natural gas in my case kicks in. Granted, this doesn’t happen often where I live, but for those few weeks in the winter, it is not something I even have to think about. And the rest of the time, I am saving money using the heat pump and not natural gas.
I doubt there can ever be high tech heat pumps which can operate at -25 C or less, because there’s so little heat energy outside and the heat pump would probably spend a majority of the time running in reverse to dethaw the unit to prevent it freezing over.
I doubt there can ever be high tech heat pumps which can operate at -25 C or less, because there’s so little heat energy outside and the heat pump would probably spend a majority of the time running in reverse to dethaw the unit to prevent it freezing over.
It could probably be done, but then it wouldn’t operate at higher temperatures. Realistically you’d probably need two heat pumps, a low temperature pump and a high temperature pump and switch between them as the temperature rises or falls. It’s double the cost and double the points of failure, and for a situation that rarely happens probably not worth it.
I’d have to imagine at some point, more heat is leaving the house than entering, and given enough time, inside and outside will eventually reach a cold equilibrium.
Would depend on how well insulated it is, but yeah since homes aren’t exactly built to be air tight there’s realistically an upper limit to the temperature delta you’re going to be able to achieve. Ultimately the question isn’t how hot/cold is the inside/outside of the house, but how big a difference are you looking at between those two.
Mind me asking what yours cost?
Just got a Toshiba unit installed in Norway and it was $3500.
Built in de froster.Price might be what makes yours strugle in colder temps.
Mine has Toshiba guts. I don’t know what I paid for it - now it appears to be selling for $1100. Mine defrosts but its defrost cycle just turns on AC for a bit instead of heat. Edit: Mitsubishi guts.
I reckon that’s your main issue.
You’d need a model designed for a colder climate.Maybe for your next one!
Man they pitchfork mob came out in full force for this one. I also live in the south and during the freeze of 2021 it was a struggle for it to deal with those low temps.
That’s precisely the freeze that led me to experience the inability of my Senville mini-split heat pump to keep up. So glad I had a wood stove. Even then, my shower drain trap froze solid. I was living in an “insulated” yurt at the time - good floor insulation, and somewhat okay wall/ceiling insualtion.
My attic insulation needs work. I swear I’m gonna get that sorted this year now that the heat has (hopefully) calmed down.
We probably live in the same neighborhood or something. NC here.
Nope. hollars from tx
Oh Jesus. I’m sorry on so many levels. Unless you’re gung ho Texan. Then I don’t know what to say except enjoy watering your foundation.
create energy
Ummm… that’s not how it works.
They actually added a correction at the end for that
A/C guy who’s the son of an A/C guy here. Heat pumps lose efficiency the colder it gets. I wouldn’t bother with one if you’re in a northern climate. Lower midwest, you might be able to save money with a heat pump over natural gas, but it will depend heavily on the cost of the respective energy. For me, in the central US, we have great prices on gas and somewhat crappy prices on electricity (vs most surrounding regions) and it’s definitely cheaper for me to stick with gas heat.
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This is the correct take for a conventional heat pump. However, there are relatively new geothermal heat pumps that can heat down to -30°C (-22°F) and are much more efficient.
Your information is outdated. It is even clearly mentioned in the one-sentence summary in the OP:
Oxford study proves heat pumps triumph over fossil fuels in the cold::Published Monday in the scientific journal Joule, the research found that heat pumps are two to three times more efficient than their oil and gas counterparts, specifically in temperatures ranging from 10 C to -20 C.
But its all irrelevant because the most effective way to keep warm is to continue with global warming. Soon we wont have a cold season to worry about. 😜
If you’re on propane, it’s more likely to be cheaper. Particularly over the course of an entire heating season, because they’re more efficient in fall and spring than the coldest part of winter.
But yeah, this study wasn’t looking at cost per therm but just raw COP, which is a pointless metric. It doesn’t even compare the number of watts of heat from burning natural gas in a furnace vs in a modern power plant that supplies a heat pump. Although since we don’t have a carbon tax, that’s only a theoretically interesting comparison.
Heat pumps work fine for most people in the north. Mitsubishi’s cold climate heat pumps supply 85% of their rated heat at -13F. Buffalo is a city known for its winters, and the last time Buffalo’s lowest temperature was below that was 1982. They’re just going to be a more expensive option for most people right now.
My father in law went to a heat pump instead of propane this year. No natural gas where he lives.
But he also dropped 20k on a solar system to power it.
How long would the return on cost savings take for it to pay itself off?
Ditto. At least with gas I’m not paying Alabama Power’s rates.
If you posted that earlier today you would have gotten a spanking for saying anything critical about heat pumps. Or people just don’t like me in particular. Hard to tell.
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You might not be totally out of luck:
- More modern units do pretty well down to -20f.
- Ground-source systems don’t care about air temps (but are more expensive)
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Yowsa! That’s cold.
That said, ground-source systems have been used to good effect in climates like that! But, of course, do what’s right for you 🙂
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How cold? Also heat pumps can have auxiliary electric heat strips, maybe even auxiliary natural gas.
Not in January in Central New Hampshire.
They work in Sweden… and Canada…
That’s great, but fossil fuels are often available in the event of a power outage, and that can save lives during a winter storm. Availability is just as important as efficiency, and until we can make our power grid more resilient, we need to factor that in.
The vast majority of gas boilers use electronics to function. In a powercut they are also dead.
Now if you’re talking diesel generator back ups, then far enough.
There are tons of non electronic gas heaters. I have one in my basement just for power outages so we can stay alive in the winter if we don’t have power. But I do think for majority of heating and cooling I would love to rip out my central furnace and replace with heat pumps but the cost is too great ATM. I have two heat pumps now, one in my garage and one in my top floor where the furnace could never reach.
I have propane heat- a small generator will power the fans while the propane provides the actual heat. The generator wouldn’t be able to handle a whole heat pump though. I do lose power a lot and lost it for 4 days straight last Jan. This situation isn’t without merit.
Even gas stoves won’t work when the power is down, for the same reason.
Heard of a match?
Some won’t let gas flow if there is no electricity.
If you want to heat air and move it around you’re gonna want a fan, which will need electricity. My gas heat is no good when the power is out.
Provided the pressure is maintained from the outside, mine would work fine with a match.
Mine had a safety valve, which was unfortunately electronically controlled.
RIP
We’re also going to run out of oil in the next 40-45 years, so we should factor that in.
I have a duel fuel system (heat pump + gas furnace) which, while more expensive, is really the best of both worlds.
In a power outage I can plug in a generator and get the furnace running.
If temps drop too low and the heat pump is struggling I can switch to the furnace.
I can choose which to run based on current energy costs.
When looking into heat pumps everyone told me they don’t work well in the northeast or they would be more expensive to run here. I found it really difficult to get an accurate estimate of the cost difference between running a heat pump vs a gas furnace. Ultimately I decided to go dual fuel for flexibility but after comparing my bills before and after I almost wish I’d gone with a hyper heat unit so it could run at lower outdoor temps because the heat pump has turned out to be cheaper but I can’t run it at low temps.
I think HVAC techs in this area are weary of them based on past experience with older units but they really have improved in recent years.
If you live in an area where power outages are common enough that you need a backup generator: Sure. but also learn how to properly install that (an improperly installed backup generator can injure or kill the utility workers trying to fix an outage) and how to safely operate it (carbon monoxide, yo). Also how to properly store the fuel and how to maintain the generator so it works for more than one year… and you don’t set your garage on fire.
Although, there are also arguments for solar power and the associated battery storage in those cases. Similarly, vehicle to load which turns a car into a battery in the event of isolated blackouts.
But if there is a power outage, the grid is already not “resilient”. So…
I wonder who the fuck is downvoting these comments. LOL - “NO FOSSIL FUELS, YOU MUST DIE IN A POWER OUTAGE!”
