PDA

View Full Version : ELI5: Heatpump System in Alberta



zechs
02-28-2021, 12:41 PM
Is a heatpump setup viable in Alberta for heat in the winter?

Is there a reason heat pumps aren't more common vs furnace/radiant heat?

My limited reading tells me a heatpump setup is one of the most efficient ways to heat a home (I suppose solar thermal is better if you are situated to properly use it).

So ELI5 me heatpump setups, and why they are/are not good for Alberta.

ExtraSlow
02-28-2021, 12:53 PM
There's a lower limit to the temperature range that a heat pump can operate. It's less efficient below about 40F (+5c) and many can't run at all below 25F (-4c).

So you need a secondary heat source for winter.

benyl
02-28-2021, 12:54 PM
I have been toying with the idea. It’s just an air conditioner in reverse. It cost prohibitive. Nat Gas is so cheap, there is no payback in efficiency.

In Alberta you still need resistive heat backup unless you have a super tight house (passive house levels).

I’ll know more in a couple of months when we start pricing HVAC.

I think the lower limit is -20 for effectiveness with the latest Mitsubishi condensers.

ThePenIsMightier
02-28-2021, 12:55 PM
Payback Period > Life Of Equipment.

#GretaEconomics

revelations
02-28-2021, 12:57 PM
My understanding is that whole house Heatpumps are not really efficient for main use in climates as cold as ours.

A split mini system can work in the shoulder seasons quite effectively though.

killramos
02-28-2021, 01:03 PM
I would imagine you would need supplemental heating in Calgary with a heat pump. Basically a NG furnace to run during the coldest times of the year as a second stage. So you aren't really going to save in that up front cost, but if you are trying to build a net 0 home maybe that's ok?

Do most heat pumps allow you to reverse the cycle and use them as AC in the summer? That might help things as you can essentially overcapitalize your AC system with an expensive heat pump, and just accept that you still need supplement heating in the winter ( NG would be recommended but you can otherwise use electric heat if you like burning money or have enough on site generation to accommodate).

Would take ALOT of solar etc. to keep a home net 0 in Calgary during the winter, esp if you are charging EV's as well ( which I bring up because if you want a net 0 home you are probably also driving an EV haha ).

Darell_n
02-28-2021, 01:11 PM
Do most heat pumps allow you to reverse the cycle and use them as AC in the summer?

Yes, the term heat pump means it works both directions.

killramos
02-28-2021, 01:20 PM
An air conditioner or a refrigerator is a heat pump and certainly doesn't function in both directions, a heat pump is a very generalized mechanical system so I hate to point it out but your definition is not rigorously correct.

zechs
02-28-2021, 01:23 PM
There's a lower limit to the temperature range that a heat pump can operate. It's less efficient below about 40F (+5c) and many can't run at all below 25F (-4c).

So you need a secondary heat source for winter.

That makes perfect sense, it seemed I was missing something very simple as to why its not more common.

Just doing some research as we get closer to building a new shop/warehouse for the business, as well as possibly a new home build in the next year or two.

On the business side of things, keeping reoccuring costs as low as possible is a big focus of mine. Natural gas and electricity are cheap, but I feel that with the way things are going, it is worth getting creative and spending some extra money to increase efficiencies where possible.

ExtraSlow
02-28-2021, 01:27 PM
The units sold as "heat pumps" for HVAC use generally work for heating and cooling. My bro has one for his cabin so his propane furnace isn't required as much, which saves on the propane deliveries. Makes a lot of sense for that kind of setup. But probably still doesn't pay out before equipment needs replacing like TPIM said.

- - - Updated - - -

As for a shop/warehouse, most are hardly insulated at all, so you could spend the money for really good insulation to reduce heating and cooling costs. Although that's not cheap. None of the solutions are cheap.

Darell_n
02-28-2021, 01:38 PM
An air conditioner or a refrigerator is a heat pump and certainly doesn't function in both directions, a heat pump is a very generalized mechanical system so I hate to point it out but your definition is not rigorously correct.

I disagree. Google ‘heat pump’ and look at the first 100 photos. How many refrigerators do you see? Lol. Heat pump in a Canadian house is 100% of the time going to be a bi-directional air conditioner.

ExtraSlow
02-28-2021, 01:40 PM
It's okay, tney didn't teach us common sense in engineering school.

killramos
02-28-2021, 01:59 PM
I disagree. Google ‘heat pump’ and look at the first 100 photos. How many refrigerators do you see? Lol. Heat pump in a Canadian house is 100% of the time going to be a bi-directional air conditioner.

Feel free to Google heat pump and click on the first link.

You might learn something.

https://lmgtfy.app/?q=heat+pump

ExtraSlow
02-28-2021, 02:13 PM
You guys know not everyone gets the same results from Google, right? They tailor that to your search history.

Mine comes up with Swedish penis pumps. Weirdly....
97794

Darell_n
02-28-2021, 02:25 PM
You guys know not everyone gets the same results from Google, right? They tailor that to your search history.

Mine comes up with Swedish penis pumps. Weirdly....
97794

Fair enough. I see they are making heat pump clothes driers now too. Interesting idea in warmer climates to cool the house while drying your clothes. But then again a clothes line is pretty energy efficient there too.

ExtraSlow
02-28-2021, 02:27 PM
My personal opinion is that energy efficiency is evil and anti-canadian.

ThePenIsMightier
02-28-2021, 02:37 PM
Dusting off some rust here, but it's a Carnot heat cycle in reverse, isn't it? What's there to debate?

revelations
02-28-2021, 02:55 PM
I disagree. Google ‘heat pump’ and look at the first 100 photos. How many refrigerators do you see? Lol. Heat pump in a Canadian house is 100% of the time going to be a bi-directional air conditioner.

I think for many the term 'heat pump' also can refer to the split mini system as well (which is just a mere component) - and also shows up prominently on my google results.

benyl
02-28-2021, 05:52 PM
It's all air conditioning. For some reason, "AC" has been associated with cooling. Likely because most of the US requires cooling over heating.

There are Heatpump Water heaters now too. Take the heat out of the house and put it in the water. Super efficient, but kinda stupid in Calgary in the winter.

I am looking at getting to Net Zero in our house build. Fuck tonne of insulation (minimum R28 walls, maybe higher and R60 ceilings). Super air tight (looking at Aero barrier).

I am still going to run a gas furnace and gas water tank. Looked at solar water heating. I was watching this link when it was -30C and the days were short. By mid afternoon, it might reach 0C.
https://www.vbus.net/scheme/844e4f8a2d2528462d3b6140c87393a5

I'm not so sure if $15K is worth running solar water heater that I have to supplement with electric heat from the grid. The $1,500 water tank seems like a bargain.

Darell_n
02-28-2021, 06:09 PM
I think for many the term 'heat pump' also can refer to the split mini system as well (which is just a mere component) - and also shows up prominently on my google results.

Yes, ductless mini splits are 99% of the heat pumps that are out there. I’m not sure a person can actually buy a mini split now that doesn’t provide both heat and cooling.

Darell_n
02-28-2021, 06:15 PM
Dusting off some rust here, but it's a Carnot heat cycle in reverse, isn't it? What's there to debate?

Correct. The issue is just the term that is associated with one specific type of equipment. Just like ‘internal combustion engine’ is going to immediately conjure up a mental imagine of a reciprocating piston motor running off dinosaur farts.

revelations
02-28-2021, 07:16 PM
I mean the reality is that many of the green systems just make no sense here.

What DOES make sense is Geothermal heatpumps - but there are big upfront costs for individual homes. Centralized geothermal (eg. bury the pipes in a new build neighbourhood) in our soft dirt would be the ideal setup.

suntan
02-28-2021, 08:15 PM
It's all air conditioning. For some reason, "AC" has been associated with cooling. Likely because most of the US requires cooling over heating.

There are Heatpump Water heaters now too. Take the heat out of the house and put it in the water. Super efficient, but kinda stupid in Calgary in the winter.

I am looking at getting to Net Zero in our house build. Fuck tonne of insulation (minimum R28 walls, maybe higher and R60 ceilings). Super air tight (looking at Aero barrier).

I am still going to run a gas furnace and gas water tank. Looked at solar water heating. I was watching this link when it was -30C and the days were short. By mid afternoon, it might reach 0C.
https://www.vbus.net/scheme/844e4f8a2d2528462d3b6140c87393a5

I'm not so sure if $15K is worth running solar water heater that I have to supplement with electric heat from the grid. The $1,500 water tank seems like a bargain.
R60 in attic is easy to do. Hell I have it. Walls should be R40 minimum. Problem is windows. They suck for R value. Best you can get is about R4. So you have to limit how many windows you have. Best not to have any. Exterior doors are also a problem.

Solar water heating sucks. Besides the inconsistent heat you'd always have to be worried about Legionnaires disease.

I just remember reading an article in FH about someone's off grid house experience long term. The couple sold the house and went back to a conventional setup. The article was trying so hard to not be negative, but a quote from the wife was telling: "I just wanted hot coffee in the morning."

Good luck.

Darkane
05-16-2021, 02:45 PM
I mean the reality is that many of the green systems just make no sense here.

What DOES make sense is Geothermal heatpumps - but there are big upfront costs for individual homes. Centralized geothermal (eg. bury the pipes in a new build neighbourhood) in our soft dirt would be the ideal setup.

Bumping thread.

So in a situation like this, How much would it affect the utility bills? I'm starting to think this may be worthy for infloor setup in the garage, and some cooling for the summer.

In the garage who cares if it 'only' makes 10C in the winter, it's perfect and must be cheaper than upfront cost of forced or Radiant heaters through the life of 20 years??

Interesting.