Last I read, which was years ago, was they still struggle under -20C. Which is not abnormal for many places in Canada. How do these perform in wicked cold times?
That, and some heat pumps are better than others. The ones that use geothermal (lines run underground below the frost line) are more expensive but don't have much issue with the cold.
they still struggle under -20C. Which is not abnormal for many places in Canada
Yes, but that's why heat pumps in this country are typically paired with auxiliary electric heat. The heat pumps still contributes some amount, even at -30 or below, but the electric "tops up" the pre-warmed air that the heat pump makes.
And that is only really needed for a couple of months out of the year, even in places like Winnipeg or Edmonton.
20-30 years ago, the heat pump technology wasn't as capable, and couldn't do the job as well, but they have improves quite a lot since then.
Yes, but that's why heat pumps in this country are typically paired with auxiliary electric heat.
Yes, and although it's not very efficient to have auxiliary electrical heat, that's a small percent of the overall year.
If you live in a home that hits -20C for 20 days per year, that's really cold! But you'll probably need the heater on for about 180 days per year at that point. Putting up with less efficiency for 20-30 days per year is still a net gain if the other 150 days of heating makes up for it.
but the electric “tops up” the pre-warmed air that the heat pump makes.
Is the heater at the hot end? The reason they crap out is that they can no longer move and vapourise their coolant, so I'd expect it to be somewhere else, probably the cold end.
I have a heat pump and furnace combo. The heat pump works extremely well down to around -10C. Below that it takes a very long time to move the needle by half a degree. The furnace doesn’t kick in until the thermostat sees the house temperature trending in the opposite direction it’s attempting to achieve.
Unfortunately, its method of determining the time gradient of temperature is rather moronic and doesn’t take the temperature schedule into account. This means every morning when the schedule calls for higher daytime temperatures (even by just half a degree) the thermostat freaks out thinking that the house is cooling rapidly and kicks on the furnace to bring up the temperature.
This causes the system to needlessly run the furnace every single morning. It annoys the hell out of me but I don’t know what to do about it. Aftermarket thermostats aren’t very common around here (Canada).
There are a variety of aftermarket thermostats available at Canadian Tire, many of which are quite good. The Home Automation enthusiasts seem to be big fans of ecobee, IIRC, and I have seen ecobee thermostats at CT.
I had a similar problem, fwiw I have an ecobee. I simply added an intermediary step an hour or two before the final temperature so the heatpump has a chance to go. There is also a threshold for auxiliary heat lock in the settings on the thermostat itself that doesn't show up in the app which I increased which helped a lot.
Many are designed for extreme temperatures now, but they are not efficient in such temperatures due to the properties of the refrigerants available. It will usually still run, but will run longer than usual and may not be able to keep up with heat demand. During a cold snap, might run continuously and may need frequent defrost cycles which further reduces efficiency and heating capacity. How cold they can/should go depends on things like sizing, refrigerant, building insulation, solar heat gain, and other factors. In a country like Canada, air source heat pumps will always be installed with a backup heat source. In Canada, that is most commonly the same natural gas furnace that the house was always originally equipped with, while the heat pump replaces the air conditioning unit, but backup heat can also be resistive electric, heating oil, wood, and more, and a decent thermostat will have an outdoor air sensor that can detect an appropriate outdoor conditions at which to switch from heat pump to backup/"emergency" heat when needed, and then back to heat pump when conditions permit.
In my experience, my heat pump provides about 90% of my heating from fall to spring. Only a few severe cold snaps put the heat pump on the bench for a few days switching over to emergency heat completely, and most of the winter it runs frequently to continuously to maintain consistent temperatures and only needs a short and occasional boost from the furnace. The gas backup is also nice peace of mind in case of a prolonged power outage due to a potential ice storm, as the furnace blower and electronic controls can easily be run off a small battery pack or generator for a very long time.
unless I am very much mistaken this is only true for air source heat pumps. If you're in a cold environment I would expect you'd want a ground source heat pump instead, although the installation cost for that will be significantly higher than air source.
Mine is rated for -25, which where i live in southern Ontario has been reached 3 times in 50 years (wind chill doesn't count remember). And while I haven't had a heat pump for one of those days I don't think it would be a problem, after all the efficiency doesn't just drop to 0, it just doesn't work as well for that one day and my house could stay a safe level of warm for a day or 2 without heat anyway.
Despite this I am required to have an auxiliary heat source, so I get charged 30 dollars a month just for a gas hook up I haven't used.
A lot of heat pumps have normal electrical heating as a backup as well.
Been a little while since I looked up the utility rates, but last I remember gas is about 1/7 the cost of electricity in Saskatchewan. Makes it hard to justify heat pumps for heating in most places. Hope the technology continues to improve and it’ll be a more sustainable option when we have a more sustainable grid.
I'm in Manitoba and am kind of in the same situation. Even though our electricity is really cheap, it's still more economically efficient to use natural gas. Coupled with just buying a new furnace and air conditioner, I don't see myself getting one anytime soon. I'd still be happier if we subsidized electric heating/heat pumps (or stopped subsidizing fossil fuels so much) but recognize I'm in a place where I can afford that and many others simply can't.
I have to pay about $50 USD per month just for the luxury of having heating in the northern US., even during the summer when I don’t need it.
R
The gas company can fucking blow me, I’m getting natural gas out of my house as quickly as I can afford it.
Note that the 240V outlets in Canada are actually just two separate 120V circuits plus a neutral. This is different from a UK outlet which has 240V AC on a single conductor and then a neutral and a protective earth.
Residential Outlets are 120V which most household small appliances and lights plug in. Oven ranges, laundry dryers, air conditioning units use 240V. Essentially they have two inverted phases: -120V, +120V to supply 240V across the two ends, usually with a NEMA 14-30 or 14-50 type plug.
I've always found this fascinating about Canada and the US. Both legs are +/- 120V potential to ground, and 240V between them. Here in Australia, everything in my house is 230V between active(hot) and neutral, both for plug in appliances and hard wired stuff like my heat pump (We call it a reverse cycle air conditioner here). Almost every house I've ever lived in has had one.
My old resistive clothes dryer just plugged into a standard 10A outlet like everything else. My current heat pump dryer uses 1/5 the energy though and has already paid for the extra purchase cost over the past three years.
In my case, it was that our local HVAC shop literally only sold one solution. I couldn't even talk them into a more powerful A/C despite having both a grow op (at the time) and server farm in the basement.
Our A/C struggles to cool the house on room-temperature days, but that's beside the point. Heat Pumps will really take off when the small time dealers start stocking them.
In my case, it was that our local HVAC shop literally only sold one solution.
In hindsight, I feel like I was taken advantage of. They even replaced my water heater "for free", but I should have been given the option to buy one outright, as I'm now stuck in a rental plan that costs way more than owning it.
And had a heat pump been offered, I would like likely gone for it.
Most of Canada's power is hydroelectric and nuclear. 60% of Canada's energy production is hydroelectric, and Ontario has three of the largest nuclear power plants in the world.