Heat pumps (air source)

[Brainonska511]

I think it also depends on your heat pump. TechnologyConnections has a pretty good video set about these:

At around 8 minutes, he shows the table for a Mitsubishi heat pump that has a COP of 2.8 at 5 F. Granted, this is probably one of the newer, more expensive variants, but there are many more than can still have COP >2-3 at 20 F.

As for "sucking heat out of your house" - if the system is setup properly, it should just be turning off the indoor blower momentarily to run the heat/cool loop in reverse to defrost, so you shouldn't be experiencing any issues with indoor comfort.

Power draw is definitely going to be better than either traditional electric heating or traditional air conditioners. The biggest draw is that it's a lot more environmentally friendly than burning gas (or other fossil fuels) for heat.

 

[pmv]

So are there any downsides to the mass adoption of heat pumps? I don't know much about it, but I would assume they use similar technology to a fridge or an AC unit? Which would imply they have the same issues that fridges do with respect to the escape of CFCs?

 

[NutBucket]

I'd say not really. They've been used for decades. I mean it's literally an AC running in reverse so not really anything crazy.

 

[cytg111]

Prices are high right now, so was gonna wait, but the way things are shaping I dont think they’re coming down anytime soon… will have to look into getting one this summer

 

[Brainonska511]

So are there any downsides to the mass adoption of heat pumps? I don't know much about it, but I would assume they use similar technology to a fridge or an AC unit? Which would imply they have the same issues that fridges do with respect to the escape of CFCs?

CFCs are not used as refrigerants anymore, and newer refrigerants that are used don't have as many problems if they do escape.

You also can't look at mass adoption of heat pumps in isolation. You have to consider what they are replacing: a myriad of inefficient fossil fuel heating sources installed in people's homes that are often fed by aging infrastructure that results in constant gas leaks, and the whole environmental impact of extracting those fossil fuels in the first place.

 

[Zorba]

So are there any downsides to the mass adoption of heat pumps? I don't know much about it, but I would assume they use similar technology to a fridge or an AC unit? Which would imply they have the same issues that fridges do with respect to the escape of CFCs?

Modern ACs typically use propane as a refrigerant, I believe new CFC AC are banned worldwide.

 

[NutBucket]

Not propane (typically R122) but regardless no CFCs.

 

[Zorba]

CFCs are not used as refrigerants anymore, and newer refrigerants that are used don't have as many problems if they do escape.

You also can't look at mass adoption of heat pumps in isolation. You have to consider what they are replacing: a myriad of inefficient fossil fuel heating sources installed in people's homes that are often fed by aging infrastructure that results in constant gas leaks, and the whole environmental impact of extracting those fossil fuels in the first place.

Even if they are replacing existing electric heat, it's resistant heating. And a heat pump will likely be 3x as efficient.

The heat pumps are the cure all though. There is also massive savings available through insulation and windows in older homes.

 

[Brainonska511]

Even if they are replacing existing electric heat, it's resistant heating. And a heat pump will likely be 3x as efficient.

That is a good point that I did not include.

The heat pumps are the cure all though. There is also massive savings available through insulation and windows in older homes.

It would also have helped a ton if we kept building new housing to replace older housing stock. So many homes in my metro area are these surviving 100+ year old tinder box triple deckers just waiting for stray embers to burn them to the ground. Crap insulation, crap windows, crap heating. If we had kept building, we'd have so many more homes that have even semi-modern building standards that also include fantastic amenities like insulation and non-drafty windows. Either way, heat pumps are still a net good for old and new homes.

 

[Dulanic]

I've been tempted to look into a heat pump when my AC dies. Especially since in TX it would be much more efficient. Works be nice to have something that can hear and cool. I'm just not sure if they can cool as effectively as a AC unit even though I know it would be more efficient for heating.

 

[Brainonska511]

I've been tempted to look into a heat pump when my AC dies. Especially since in TX it would be much more efficient. Works be nice to have something that can hear and cool. I'm just not sure if they can cool as effectively as a AC unit even though I know it would be more efficient for heating.

A heat pump is basically a central AC system that has a valve that lets it run in reverse to heat a space instead of cool. I don't see why it couldn't be as efficient as a typical central AC system.

 

[Zorba]

Not propane (typically R122) but regardless no CFCs.

I think you are thinking of either R-22 or R-134a, both of which are now banned and/or being phased out.

Propane is R-290 and Isobutane is R-600a, both are becoming more common. (Note, they aren't the same as the propane you buy at Flying-Js, much more pure and have oils added to them to lubricate the compressor.

R-410a is the other one I see on a ton of new units in the US.

 

[Zorba]

It would also have helped a ton if we kept building new housing to replace older housing stock. So many homes in my metro area are these surviving 100+ year old tinder box triple deckers just waiting for stray embers to burn them to the ground. Crap insulation, crap windows, crap heating. If we had kept building, we'd have so many more homes that have even semi-modern building standards that also include fantastic amenities like insulation and non-drafty windows. Either way, heat pumps are still a net good for old and new homes.

I agree. That is the problem with houses being an appreciating asset, old shitty homes rarely get replaced with a well built modern home. My SIL has a 1947 house mo insulation, leaking windows, hacking central heat/air. They use 3x the utilities we do on a house half our size. Of course when they "remodeled" it, they only did cosmetic things nothing that would make it more comfortable or efficient.

When I was grad school, getting my masters with a heat transfer focus, I lived in a house built in 1903. The lack of insulation made it there where you had to have it 78 in the winter to not freeze and 65 in the summer to not sweat. Really made me understand the "Comfort" part of HVAC/building envelope design. I think the walls had less insulative value than when I lived in a cinder block apartment.

 

[NutBucket]

I think you are thinking of either R-22 or R-134a, both of which are now banned and/or being phased out.

Propane is R-290 and Isobutane is R-600a, both are becoming more common. (Note, they aren't the same as the propane you buy at Fly-Js, much more pure and have oils added to them to lubricate the compressor.

R-410a is the other one I see on a ton of new units in the US.

You are right. I was thinking of 410.

 

[pcgeek11]

You just reverse the cycle for a few minutes to thaw the condensation.

This all heat pumps that I know of have a defrost cycle built in. I have been using one since 1990 and have no complaints.

 

[snoopy7548]

When my central AC goes (it's approaching 10 years old, but still going strong), I'll look into replacing it with a heat pump.

I use propane for heating, but it would be nice to have a dual fuel setup so I would only need to use propane when it gets really cold. On average, I only get my 500 gallon tank filled 1.5x per year, though the price of electricity is high (MA).

I'd have to run some numbers to see if the expected cost savings is worth the extra money for a heat pump.

 

[Muse]

Wood burners are cheap/efficient for btu's, but yeah there's health concerns. Wood pellets are much better (we have one, love it). More efficient, and better for the environment.

The last year or two on the seldom occasions I light a fire in my fireplace I wear an N95!

 

[[DHT]Osiris]

The last year or two on the seldom occasions I light a fire in my fireplace I wear an N95!

Why? There's about a hundred things you encounter on a daily basis more likely to cause you harm than smoke particulates from a fireplace.

 

[Muse]

Why? There's about a hundred things you encounter on a daily basis more likely to cause you harm than smoke particulates from a fireplace.

huh? Dunno about that. Got info from a real smart guy (Harvard grad in math) that the particulates from a fireplace are a serious health issue.

I'm even wearing an N95 on my daily 10 mile street skates. The one day I didn't in the last month (~4 days ago) felt nasty, my nose acted up in a nasty way and I decided to just keep wearing it. It's not the covid threat in the streets. It keeps air from rushing into my nostrils, which is a big help. Also, it filters out the allergens pretty completely, plus particulate matter from whatever. I don't mind the mask, and don't give a damn how I look to folks out there.

 

[pmv]

Why? There's about a hundred things you encounter on a daily basis more likely to cause you harm than smoke particulates from a fireplace.

Not sure how to reconcile that claim with the stories in my earlier post. Those claim that the particulates from _other people's_ fireplaces are one of the most harmful things you encounter on a daily basis. Presumably your own are likely to be even worse.

Heat pumps (air source)

All the posts about heat pumps that I could find in the "Russia invades Ukraine" thread in P&N have been moved here. This thread was actually started by Atari2600 with post #22. admin allisolm Germany really dropped the ball the last two decades becoming so dependent on Russian fossil fuels...

forums.anandtech.com

 

[[DHT]Osiris]

Not sure how to reconcile that claim with the stories in my earlier post. Those claim that the particulates from _other people's_ fireplaces are one of the most harmful things you encounter on a daily basis. Presumably your own are likely to be even worse.

Heat pumps (air source)

All the posts about heat pumps that I could find in the "Russia invades Ukraine" thread in P&N have been moved here. This thread was actually started by Atari2600 with post #22. admin allisolm Germany really dropped the ball the last two decades becoming so dependent on Russian fossil fuels...

forums.anandtech.com

Because in your own home, you shouldn't be experiencing much, if any of that particulate matter. It's supposed to be going up the chimney. If you're breathing in smoke inside your home you've got something janky going on and you're probably going to die from asphyxiation soon. If you're outside, yeah, there's lots of stuff out there including other people's stoves, vehicle exhaust, etc.

Long term, you'll have more issues from odd-ball shit like burning propane stovetops, alpha radiation from food prep on granite, good old fashioned food poisoning, etc.

 

[NutBucket]

When my central AC goes (it's approaching 10 years old, but still going strong), I'll look into replacing it with a heat pump.

I use propane for heating, but it would be nice to have a dual fuel setup so I would only need to use propane when it gets really cold. On average, I only get my 500 gallon tank filled 1.5x per year, though the price of electricity is high (MA).

I'd have to run some numbers to see if the expected cost savings is worth the extra money for a heat pump.

It might make sense to install one when you need to replace your system but may not make sense to run in the winter unless propane goes up or you install solar or something.

 

[K1052]

It might make sense to install one when you need to replace your system but may not make sense to run in the winter unless propane goes up or you install solar or something.

Last I saw propane prices are up quite a bit.

 

[NutBucket]

I'm sure but I'm aware some areas have very high electricity prices too. "It depends"

 

[snoopy7548]

Last I saw propane prices are up quite a bit.

Yep. Up to over $5/gallon, a nearly 3x increase from what I've historically been paying.

Electric prices are about $0.3/kWh which is pretty insane as well, but my current bill is still under $100.

It's hard to stomach the thought of paying $1500 to fill my propane tank when I've always paid around $500-700, especially when the heating season is so close to being over.