With the cold weather I was hoping to hear of some experiences people have had with their heat pumps.
What kind of backup heat do you have? Are you using it? Is there some temperature where you just stop using the heat pump, or are you even consciously thinking about it?
Thanks!
From what I understand, you only use a heat pump until the outside temp reaches 0c, maybe -5c. Below that you go back to using the furnace.
One of the big draws of a heat pump is pumping heat “out” of the house in summer instead of running an air conditioner. If you get a chilly spring night, the heat pump should maintain the house temp without running the furnace. Supposedly it does both of these more economically than running an AC and furnace, but it is not a replacement for a furnace.
This is outdated. Modern heat pumps are good down to -15 or even -20 and new models are getting more and more efficient every day.
That’s not to say folks in Alberta shouldn’t maintain a backup furnace of some kind, but today a heat pump should be good for heating and cooling 300+ days a year.
Also:
There’s nothing “supposed” about it. It’s basic physics: moving heat around is far more energy efficient than heating something up directly.
Any brand recommendations?
Senville claims that some models are good to -30C. Even their “cheap” stuff seems to be good to -15 or -20
Mine works down to -25 or -30C, then the electric heat coil in the furnace kicks in.
Wow - so you’re saying not until around -25 to -30 does supplementary heat kick in? Is there cool air being blown out your vents 24/7 around that temperature?
Not at all… It’s consistently warm, the system stops running the heat pump when it’s not getting enough heat from the outside unit, and turns on the electric heater.
That would be the heat pump heats well enough until those temperatures
Good to hear. As soon as we can afford it, we’ll be installing one.
The subsidy doesn’t cover us because we’re in a mobile home. If we get someone to pull the axles off, we’d qualify, but that’s yet more money.
Theres a subsidy?
The federal government has one that is part of their Greener Homes Program. I believe there’s also an Oil to Heat pump program.
We took a look at it for our place in Calgary when we installed our air conditioning, but the incentive was for around 5k. The provincial government doesn’t offer anything here, so the A/C unit we looked at was about $4,500 done and dusted for a 2.5 ton name brand vs. about $12,500 for a heat pump. I’ll tell you, if the subsidy would have covered another $1.5 to 2k, I would have taken a much much more serious look at it, just for even the AC aspect alone. Or if the province offered anything, but it’s all oil and gas here, and the provincial government is much too busy lining their own pockets and the pockets of their supporters with single sourced procurements, but anyways
My FIL, who lives in Southern Ontario, put one in and loves it. He said it was a slam dunk decision with the subsidies, as there are both provincial and federal ones there I believe.
12.5k? Ouch. What size house?
1600sq ft. We need a cold climate pump, which is more expensive.
In the short term, it might make more sense to spend some money on insulation… My uncle lived in one in Northern Ontario, and even though it was skirted and sheltered by the forest around him, the fuel costs each winter were punishing.
Already done! :)
It works maybe, but it’s definitely not efficient at those temperatures. Plus your unit won’t last very long if you are driving it that hard. Lots of bold claims by these manufacturers, but let’s check in, in a couple of years to see how that’s going for the units.
My pool pump, the minute it hits about 6 degrees out, it starts icing and efficiency is out the window. I have to shut it down at night, because it often gets too cold in the evenings for it on the prairies, even in summer. When it hits about 10 degrees outside though, you fire that bastard on and it’s warm in like 2 hours tops.
Less efficient, yes, but the system knows the temperature outside, and switches to electric heat automatically. Also, -40C is usually for short periods of time, and becoming more rare – the advantages far outweigh the issues.
As for your pool – it’s likely not built to the same standard as your home heat pump – and the icing sounds like a problem that might require some maintenance.
The pool heat pump is fine, it’s a smaller unit so it’s not like a house one that can go to low temperatures. We also live at 3,400 feet of altitude, the operating curve for heat pumps is different at any altitude vs what they are at sea level (which is what I believe the manufacturer quotes it at). When we bought it, that was one thing that was mentioned in the literature, that they aren’t as efficient at higher altitudes and thus can’t operate at as low of temperatures.
Keep in mind that while the heat pump works at low temperatures, it produces less heat. Senville’s 36000BTU unit produces just 27000 BTU at 17f per AHRI. The drop in output is an important consideration when evaluating system sizing and backup/auxiliary heating.
Thanks for the additional information! I’m still trying to get past all brochures and promotions to real data.
I have found NEEP’s tool extremely useful
Bookmarked! Thanks.
Daikin, Mitsubishi say -13F.
You can switch on an aux heat source after that. Resistive, gas, wood. Most air handlers have optional resistive heat.
An air conditioner is a heat pump. Very little difference.
It’s not quite that simple; the output drops as the temperature gets really cold, so auxiliary heat likely kicks in before the heat pump actually shuts off. They’re still great, efficient technology, but when considering auxiliary heating needs and system sizing, the reduced output at low temperatures needs to be considered.