Heat pumps can’t take the cold? Nordics debunk the myth::By installing a heat pump in his house in the hills of Oslo, Oyvind Solstad killed three birds with one stone, improving his comfort, finances and climate footprint.
Heat pumps can’t take the cold? Nordics debunk the myth::By installing a heat pump in his house in the hills of Oslo, Oyvind Solstad killed three birds with one stone, improving his comfort, finances and climate footprint.
How is this a myth? Nobody with more than two braincells thinks that heat pump heaters don’t work in the cold.
If we start comparing everything that idiots think to a mythological mystery worthy of note, we’ll be here for an eternity.
This is not a myth but a fact, heat pumps don’t work at extreme cold temperatures.
What temperature exactly depends on the coolant used.
The efficiency also degrades at lower temperatures.
This is a random example of first hit I got on a heat pump.
https://heatnow.dk/produkt/altech-sirius-9-varmepumpe/
Notice the effect drops dramatically below -20 C°.
But this is a pump sold for the Scandinavian market, therefore it is of course designed to work at low temperatures. It doesn’t state the minimum, but I’m guessing it would be around -40 C°. Which is very good compared top older models.
But that’s not sufficient. As the temperature gets colder, it’s not just less efficient but produces much less heat. At the lower temperatures, it may not be able to keep up. Since it would be wasteful most of the year, heat pumps aren’t sized for that
The heat pump I just had installed in SW Ontario hands over heating duty at -10C to the gas furnace
How much did it cost and what rebates are available? I’d love to say fuck Enbridge.
$12K for the heat pump and furnace. We’re expecting a $7K rebate (did the replacement before the audit because the old furnace died)
You could have gotten a whole home mini split from senville for less and it works down to -30. My heatpump from 15 years ago only did down to -10.
I found all the HVAC guys in my area were still really pushing the heatpump and furnace combo because that’s what they knew and not what was best, cheapest or most efficient.
How does a mini split system work? Does it plumb into traditional ducting?
Edit: just looked them up. Also found out that a friend out East with an older, oil heater house (no central ducting) was quoted a mini split for their place at over $20K
Our place is a four bedroom, two storey with a basement. I wonder if a mini split with the requisite air handlers would be cheaper
On a side note, we have a West facing room with large windows that I have to run a portable AC and space heater in as it’s temp is always extreme vs the rest of the house. A mini split just for that room would be great
They are honestly pretty easy to install if you are at all handy. The smaller ones (like for a room) have minimal electrical needs and are something you could get an electrician buddy to do for a case of beer if you buy the parts off amazon. Depending on the brand they are varying levels of DIY but nothing a 5 min youtube video can’t teach you. All in for my house it was 6k and a saturday afternoon to get it done.
How many mini split heat pumps and air exchangers did you put into your place
Overall, we should be net $5K with an installer because of rebates, but it’s good to know cheaper alternatives are available
My quote from the installers that were on the list of qualified installers for the rebate was always around 20K and up for a 3 head system. It was not worth paying the premium to get the rebate but I’m pretty handy on the tools.
I could break my system completely 2 times and still come out spending less when I bought a 3rd one compared to having a “Qualified Pro” install it for me. Especially since I now have all the hole saws, vacuum pump, flare kit, electrical is done etc, so there is no added expense beyond buying the unit now.
If you are not comfortable with gas fittings, electrical, cutting holes in the side of your house etc… It might be a different calculation.
The one I bought is under 4k CAD. https://senville.ca/36000-btu-tri-zone-mini-split-air-conditioner-sena-36hf-t/ and is medium DIY friendly.
You can get brands like Mr.Cool that are very simple to install.
Damn that ain’t cheap. What’s the expected savings per year in reduced gas/hydro?
Edit - how quick is it expected to pay itself off
Generally, don’t replace a working one that has any reasonable good time left in it.
If you’d expect it to last 15y, if it’s working fine after 14y, wait 2-3 more years at least.
I’m not sure, likely somewhere between 5-7 years.
We wouldn’t have done it if our furnace wasn’t shot. As a plus our A/C leaked it’s freon in the winter, so replacing it was an improvement as well.
It’s not that people think they don’t work in the cold, it’s that they are less suited for the areas or days of extreme cold.
Which is why you have a backup system. I have a net zero house in Saskatchewan, Canada. My Carrier heat pump will operate to -15C, and switches to electric heating coils in the air handler if it’s colder outside. It’s a rather extreme climate here, but in most other places, you’d be fine with some baseboard heaters as backup.
It really depends on the type of heat pump. Air-sourced heat pumps generally don’t produce heat below -30C and below -10C they generally lose enough efficiency that you’re better off using electric baseboard heating.
My air sourced heat pump keeps my house warm just fine in the Finnish winter where temperatures of -30C aren’t unheard of. I’m not exactly sure how it works, but I assume there’s coils that’ll produce the heat by electricity if nececcary, making it at worst as efficient as direct electric heating, which is what I’d use otherwise. Here like every other house has a heatpump like that and I don’t remember hearing anyone ever complaining that they’re not working.
The argument is bullshit in totality. But… When the supplemental electric heating coils come on, it is less efficient ON THAT DAY, than the alternative electric options. But, like I said, in totality, it’s more effective over a month, and certainly better over the course of a year. It’s a matter of people with an agenda cherry picking the 9 days a year in which it is less efficient and pretending that the other 354 days don’t count.
I suppose if electric heat is the primary option then sure. Around here though natural gas is pretty much ubiquitous and the cost per joule is a heck of a lot lower than electricity. About $6/GJ for natural gas, compared to about $42/GJ for electricity. Would need a pretty efficient heat pump to see the cost savings in my area.
There are heat pumps now that use gas to do the supplemental heat. Those are the best possible option. They are equally efficient to a gas furnace when supplementing, and even cheaper when not.
I’m sure there’s applications where that’s true, but then you’re essentially talking about having a gas furnace plus a heat pump, so you’re installation cost is close to the sum of both systems. Energy rates vary by region, but around here electricity is about 7 times the cost of gas, so a heat pump running at a coefficient of performance around 3 would still cost twice as much to run as a natural gas furnace, it would be cheaper to just turn off the heat pump altogether and only use that “supplementary” heat.
When I was looking at new heat pumps the hybrid ones were between 500 & 1000 more than the equivalent electric ones.
It’s not a sperate unit, it just has a gas heater in place of the electric supplemental coils.
It depends what you mean by the alternative electric options. Electric resistance heating is 100% efficient and that’s what my heatpump effectively is when it gets cold enough. It’s not less efficient than wall mounted electric radiators even when it drops to -30C. You just lose the efficiency of a heatpump for that time.
Exactly - people somehow fail to understand that Heat Pumps, by necessity, are always more efficient than 100% of an equivalent electric solution.
Except that electric heating is always 100% efficient, and that’s what a heat pump falls back to. If anything it will still be more efficient than baseboard heating simply due to it having a fan to better distribute the heat (equivalent to an electric furnace with ducting). The only argument that makes sense is when comparing costs with other heat sources like natural gas, which is a whole other topic.
I think mine is undersized and close to 20 years old now. Reading your response is yet another reason I have to go through with upgrading everything.
Generally you’d have a backup heat source with an air-to-air heat pump for those really cold days like -15C and colder, like a gas furnace or a heating element unit inside (like with electrical coils). Air-to-air heat pumps are more efficient on warmer days, on colder days they would be less efficient but you’d still have a backup heat source so it would still “work”, so the article is still somewhat correct in that sense.
Also, electric baseboard heaters can be quite a bit louder than forced-air systems with a heat pump, so you’d still be better off with a heat pump in those cases.
It just comes from a fundamental misunderstanding of how the universe operates.
They say oh well it’s cold outside so how can it make it warm inside? They say this because they have absolutely no understanding of where the concept of a temperature comes from. They think that if it’s 10° outside then there is 10° of energy outside presumably out to some arbitrary distance, because some places are warmer, but they don’t really think that bit through. They don’t realise that’s not how it works.
MFers need a refresher on the concept of absolute zero.