OT - Looking for advice: Heat pump vs. AC for cooling

GrateEggspectations · May 8

We are due to replace an air conditioner and are currently debating between a heat pump and a replacement AC unit.

The climate here, in Ottawa, Ontario, sees dry, cold winters (sometimes -30 or -35C, without wind chill) and hot, humid summers (sometimes 35C without humidex). Temperatures here are cold enough that a furnace will be necessary regardless of our choice (our furnace is older, but still fully functional at present).

It’s possible there may be government rebates were we to opt for a heat pump, though it sounds like AC may still be cheaper.

As far as usage, we heat consistently throughout the fall and winter months, and alternate between AC and open windows in the spring and summer (preference being for open windows if it’s not too hot and/or humid; so we sometimes cool one day and have the system off the next in favour of open windows).

Would appreciate input from those in the know. Would especially appreciate hearing from @lkapigian, given his expertise (but no pressure to respond, Larry).

Many thanks in advance!

Begger · May 8

Here in South California? Solar (PV) and backup batteries are used to defray costs.
You produce enough surplus power over the course of a day to run the heat pump overnite.
Heat load is drastically eased by sundown. It works out.
Here where I live? I get charged aboutt 6x or 7x against what I'm Paid for my extra juice. That's why batteries are such a terrific idea.
Now? Ottawa? I doubt you get enough sun to make it workwhile. I'd wonder about snow and such, too.

fishlessman · May 8

I’m a fan of open windows and fans. Only gets over a hundred a few days here and usually a slight breeze. Ac gets things stuffy for me. Heat pumps don’t work when it’s frigid cold so half the time they stay off

alaskanassasin · May 8

@lkapigian

lkapigian · May 8

I would definitely go Heat Pump , in fact it’s pretty much all we are installing nowadays, and the heat pumps straight up costs are lower than gas furnaces ( at least in California with our pollution restrictions)

Carrier 37MUHQ paired with 45MUHAQ is our most popular, you’d still likely need minimal back of ( strip heat ) but where I am it’s not needed , good to go down to 0F no back up

Infinity GreenSpeed is even more efficient and hits the rebates, you can also go Hybrid Heat ( Heat pump with furnace for defrost and super cold days) it will run heat pump mode when most efficient and switch to gas when not

lkapigian · May 8

Begger said:

Here in South California? Solar (PV) and backup batteries are used to defray costs.
You produce enough surplus power over the course of a day to run the heat pump overnite.
Heat load is drastically eased by sundown. It works out.
Here where I live? I get charged aboutt 6x or 7x against what I'm Paid for my extra juice. That's why batteries are such a terrific idea.
Now? Ottawa? I doubt you get enough sun to make it workwhile. I'd wonder about snow and such, too.

Are you on NEM 3?

Botch · May 9

I got a heat pump/new gas furnace installed three years ago. My gas bill in the winter, and my electric bill in the spring/summer/fall, rarely rise above $100/mo (and sometimes one or the other is less than $20!). Got some nice, one-time tax breaks, but the system won’t pay for itself in my lifetime.
My only issue with my system (Lennox) is that it’s so finely-tuned that my circulation fan(s) seem to run 90% of the time. I’d prefer it more quiet.

dbCooper · May 9

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

lkapigian · May 9

Getting so bad in California , even water heaters Heat Pump Water Heaters are required on new builds and soon won’t be able to buy a gas one , Hybrid only

alaskanassasin · May 9

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

lkapigian · May 9

alaskanassasin said:

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

Geothermal “ water source heat pumps “ are nice but ya, if you are in a neighborhood and have to go down vs horizontal I would not do it, if you are near a stream that has water year round that is ideal, just grab that

fishlessman · May 9

lkapigian said:

alaskanassasin said:how about.

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

Geothermal “ water source heat pumps “ are nice but ya, if you are in a neighborhood and have to go down vs horizontal I would not do it, if you are near a stream that has water year round that is ideal, just grab that

How about a frozen lake.

lkapigian · May 9

fishlessman said:

lkapigian said:

alaskanassasin said:how about.

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

Geothermal “ water source heat pumps “ are nice but ya, if you are in a neighborhood and have to go down vs horizontal I would not do it, if you are near a stream that has water year round that is ideal, just grab that

How about a frozen lake.

lol , go deep

MaskedMarvel · May 9

Next one we put in here (central NC) will be geothermal. There just isn’t any long term argument against it. Wish I’d linked format to begin with (current unit is around 8 years old now and fantastic).

fishlessman · May 9

lkapigian said:my neighbor put it in plus a boiler. Boiler is still running.

fishlessman said:

lkapigian said:

alaskanassasin said:how about.

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

Geothermal “ water source heat pumps “ are nice but ya, if you are in a neighborhood and have to go down vs horizontal I would not do it, if you are near a stream that has water year round that is ideal, just grab that

How about a frozen lake.

lol , go deep

Neighbor put it in last fall but the new house still has the boiler running. They put heating/cooling in th new floor slab. There is cold spring water a foot and a half under the floor slab so I’m still wondering why the heat pumps

lkapigian · May 9

fishlessman said:

lkapigian said:my neighbor put it in plus a boiler. Boiler is still running.

fishlessman said:

lkapigian said:

alaskanassasin said:how about.

dbCooper said:

Although many times they're not cost competitive, I'd add ground source heat pumps into the research/bid process. No backup heat source needed with them.

I saw a homeowner installing one of these in a neighborhood… it was pure chaos

Geothermal “ water source heat pumps “ are nice but ya, if you are in a neighborhood and have to go down vs horizontal I would not do it, if you are near a stream that has water year round that is ideal, just grab that

How about a frozen lake.

lol , go deep

Neighbor put it in last fall but the new house still has the boiler running. They put heating/cooling in th new floor slab. There is cold spring water a foot and a half under the floor slab so I’m still wondering why the heat pumps

No idea unless they want backup forced air, also with a water source heat pump and a boiler there it’s a good fit , we have systems call “ California Heat Pumps “ where we use an exceeding small “ boiler” ( overgrown water heater) heating entire office complex and just maintain the water loop 60-70 degrees

GrateEggspectations · May 12

Many thanks to all who have chimed in.

Had one company in today.

Most likely scenario may be heat pump with simultaneous furnace replacement.

Another company to come in for a quote tomorrow.

kl8ton · May 12

My parents just mentioned this yesterday. They had it quoted and heat and cooling was cheaper than AC only. For what it's worth.

michaelgogogo · May 12

We built our two story (4200 sqft - 390 sqm)house in 2000, installed geothermal (horizontal ground source loop) with in-floor heat on lower level supplied by gas hot water heater. We don't really use the in floor heat much and the hot water heater was help by the desuperheater of the geothermal system.

We don't have a separate furnace. The system takes care of heat in the winter and cooling in the summer. Nice not to have an A/C unit outside with all its noise.

In 2000 geothermal was pretty new in the area. So new in fact, that local code required us to have a back up heat source. Between a gas fire place and the in-floor heat we qualified. I asked the inspector if they required traditional furnaces to have a backup and they looked at me like I was crazy. I was crazy???

After 25 years we had it replaced with a Waterfurnace geothermal system. We were able to take advantage of some rebates.

We just replaced the unit, all the piping outside was fine. The water heater was on its last leg, so we also replaced the water heater with a tankless gas water heater.

The Waterfurnace system has a desuperheater that is used to preheat the water going to the tankless water heater. There is a simple storage tank that has preheated water in it. Mostly the desuperheater works more in the summer when there is extra heat.

We did not need to add auxiliary heat option to the Waterfurnace as we haven't had a problem with not getting enough heat. So heating and cooling are all done with the geothermal unit.

OT - Looking for advice: Heat pump vs. AC for cooling

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