more heat pump questions

[Fritz]

previously, but ....

In late '22 our indirect HW tank failed and was replaced. The gas heating system failed around Xmas of '22.
There was no way I was gonna hire a heat pump install at that time in the cold.
Grinned and bared a new gas-fired heating system.

But we'd like to have a heat pump for cooling and hopefully, primary heating, as well, as the system is spec'd to -15ºF. Though it never gets hat low here. 30º is the avg winter.

Is there a general thought on % saved in gas costs and % additional in electricity costs? Obviously, therms and kWh prices vary everywhere, so I'm not looking for a dollar amount.
We're in zone 7.

[mrbigstuff]

Neighbor just had one installed two years ago. His installer has returned about a half dozen times to fix or tweak things on the system but it's been good for the most recent six months or so. The big but is that he also has to maintain his oil fired boiler because the heat pump doesn't keep it warm enough on very cold days. So, if you're good with two systems it might work for you. Me, I think the retrofit is hideous (and problematic) on our wood frame century plus old houses in this neighborhood, so I'm waiting on PV at some point and maybe a geothermal water system.

If I were to build a new house, I'd install some sort of heat pump for sure.

[Fritz]

yea, friends just knocked down their varmint-infested and rebuilt with geo-thermal. But they have the land and obviously the dough re mi.

[Thrift Store Scott]

mrbigstuff wrote:
Neighbor just had one installed two years ago. His installer has returned about a half dozen times to fix or tweak things on the system but it's been good for the most recent six months or so. The big but is that he also has to maintain his oil fired boiler because the heat pump doesn't keep it warm enough on very cold days. So, if you're good with two systems it might work for you. Me, I think the retrofit is hideous (and problematic) on our wood frame century plus old houses in this neighborhood, so I'm waiting on PV at some point and maybe a geothermal water system.

If I were to build a new house, I'd install some sort of heat pump for sure.

That's been the main complaint against heat pumps I've heard even down here in the warm & sunny South- They don't do a very good job of heating on the coldest days, and most people wind up using some sort of supplemental heat (fireplace, wood stove, space heater, kerosene heater, etc.) in addition to the heat pump to stay comfortable.

[kj]

I'd like to piggyback on this thread and ask what is happening with the government incentives that are supposed to happen? Supposedly this round of heat pump can do a better job than the old ones that required supplemental heat, but that's a we'll see about that.

[numbered]

The new heat pumps are better and can work in most moderate parts of the country. Below 10 degree F temps may be a problem, and would require resistive heating (available in most models) or a gas backup. My MIL has a heat pump in Montana and it works pretty well. However, during the couple weeks a year of -20, the resistive units get a work out.

The issue on costs is the price comparison between kW and therms in your region. The MIL pays .15/kW and the alternative is propane. Her choice is pretty clear.

Here in Cali our power costs are outrageous (.45/kW and getting worse as we demand utilities underground lines for fear of fire.) I do not think heat pumps are economical here without solar.

With solar--and enough solar--the curves are closer. At least for heating. Then the issue turns on how much AC you need. Heat pumps are better than older condensers so it may pay off in hot summer temps...

[kj]

Well, there is also the benefit of decreasing fracking and stuff like that, so if you are one who cares about such things, it doesn't have to be cheaper. I think our climate in boise is probably perfect for a heat pump, but I remember reading about subsidies similar to electric cars except for heat pumps, so I'm waiting to see what happens there. Our air con is also ridiculously inefficient, so a new heat pump would also help that quite a bit.

[pdq]

numbered wrote:
The new heat pumps are better and can work in most moderate parts of the country. Below 10 degree F temps may be a problem, and would require resistive heating (available in most models)…

^this.

Resistive electrical heat is expensive and less efficient (like only ~100% efficient, instead of the 250% efficient in normal heat pump operation), but it’s only for a couple of days.

[Michael]

We got 2 heat pumps when we built our house 32 years ago. The backup is resistant heating. The original heat pumps just ran cool all the time--until the resistant heaters came on when the heat pumps couldn't handle the real cold weather (about 20 degrees if I recall). Move forward 15 years and I replaced both with more efficient units. They cost a bit less to run but, again, the air felt cool even though it was at the right temperature. Then about 5 years ago we lost a thermostat to a lightning strike. I bought a new $40 Honeywell thermostat and it was an amazing change. They don't feel cool anymore. I asked the heating and air guy about it and he said they now turn on the resistant heating just a bit to make it feel warmer while the heat pump does most of the work. I figured our bill would skyrocket but it didn't. It must have gone up a bit but it wasn't noticeable to me. We don't use the automatic setback on our units. It's 72 degrees in the winter and 78 degrees in the summer. When we leave I'll turn it down to 60 degrees and leave. Coming back it takes maybe half an hour to warm up--the resistance heaters are on until it gets to about 70 and then they turn off and the heat pump just operates on it's own. I'm really happy with the heat pumps.

[Fritz]

starting to lean towards replacing the wall ACs and leaving the big job for the next person. $4k savings.
But I'll have to look at the resistive heating aspect of what I was quoted.
The new Burnham X205 is just humming along.
The carbon factor is we don't and won't be getting alt energy here. Trees make panels an $$$ proposition as well.
I'd say most of the electricity here is still prolly fossil.