CALIFORNIA ENERGY COMMISSION - Heat Pumps Are the Wave of the Future.

[GoldDigger]

One specific design issue of these specific units is that the indoor temperature sensor is built into the indoor unit.

This means that the system has to circulate air when the call for heat has been satisfied (at least that is my understanding for why it was designed to do so), and so the system will produce a cool breeze between heating periods when heating requirements are low.

Regarding the low temperature function, I should be clearer: I do not have personal experience with the system on the coldest days. I did not mean to imply that I wouldn't like the system on the coldest days. I did _try_ one of my units on a really cold day last year. It seemed to sound like it was struggling, but it did make heat.

Jon

The Panasonic unit I have experience with turns the indoor fan on at low speed for a short period of time at intervals when there is no heating or cooling demand. So the extra breeze is minimized. But you can also set the inside fan to run continuously for better temperature regulation.
The weakest point in the unit operation, in my opinion, is the implementation of Auto Heat/Cool. The problem is that regardless of how you set the heating and cooling temperatures, there seems to be an almost 8 degree dead band between Heating and Cooling.
For a system with two indoor units, the problem of manual Heat versus Cool selection is tedious. To be sure that the switch is immediately effective, I have to turn off both indoor units, change Mode on both of them and then turn them back on again.

 

[Frank DuVal]

If you suspect your flares are not good, Nylog Blue!

My flares are usually good, never had a leak in the past, but hey, a little Nylog Blue is insurance.....

 

[PaulMmn]

No one has talked about ground-source heat pumps. I think they're the wave of the future-- if the cost of installation can be tamed. You run a compressor in the basement, and it provides domestic heat (and hot water in some installations). I'm thinking the energy need to run the thing would compare to the cost of running your A/C constantly. I'm thinking no coil freeze ups trying to suck heat out of 32* air!
Has to be less than the cost of gas/oil furnaces (including fuel costs).

 

[Jraef]

My gas heater is on its last legs, and my A/C is now 25+ years old. When I had a gas leak in the ceiling (caught by the Cable guy), I told my plumber that I was planning on replacing both the gas heater and A/C system with a heat pump this coming year. He was of the strong opinion that the HP was a bad idea because our weather situation makes it ineffective in winter. I looked into it deeper after that and discovered he is 100% wrong, we are in the BEST situation for it to work, especially since I have solar. So I think a LOT of opinions on this subject are being skewed by personal biases, ie “What will I, as a plumber or HVAC guy, stand to gain or lose?”

 

[mtnelect]

The Panasonic unit I have experience with turns the indoor fan on at low speed for a short period of time at intervals when there is no heating or cooling demand. So the extra breeze is minimized. But you can also set the inside fan to run continuously for better temperature regulation.
The weakest point in the unit operation, in my opinion, is the implementation of Auto Heat/Cool. The problem is that regardless of how you set the heating and cooling temperatures, there seems to be an almost 8 degree dead band between Heating and Cooling.
For a system with two indoor units, the problem of manual Heat versus Cool selection is tedious. To be sure that the switch is immediately effective, I have to turn off both indoor units, change Mode on both of them and then turn them back on again.

I install Diakin. They have man options, just to mention a few:
1) Optical Sensor: If the room is empty will automatically turn off that room
2) Select Main Room: Priority on which room you want to function first
3) Error Alert: Will display a code on the remote

 

[mtnelect]

My gas heater is on its last legs, and my A/C is now 25+ years old. When I had a gas leak in the ceiling (caught by the Cable guy), I told my plumber that I was planning on replacing both the gas heater and A/C system with a heat pump this coming year. He was of the strong opinion that the HP was a bad idea because our weather situation makes it ineffective in winter. I looked into it deeper after that and discovered he is 100% wrong, we are in the BEST situation for it to work, especially since I have solar. So I think a LOT of opinions on this subject are being skewed by personal biases, ie “What will I, as a plumber or HVAC guy, stand to gain or lose?”

I install Diakin, because I believe they are the best. You don't have to air condition the whole house.
1) Ducted System:
a. They leak, and waste energy.
b. They are not designed properly.
c. They are subjected to the environment, especially in attics and crawl spaces.
2) Engineering Heat Loads: Mostly never done, just "Rule of Thumb"

 

[retirede]

No one has talked about ground-source heat pumps. I think they're the wave of the future-- if the cost of installation can be tamed. You run a compressor in the basement, and it provides domestic heat (and hot water in some installations). I'm thinking the energy need to run the thing would compare to the cost of running your A/C constantly. I'm thinking no coil freeze ups trying to suck heat out of 32* air!
Has to be less than the cost of gas/oil furnaces (including fuel costs).

The last time I calculated, my electricity costs 16 times my nat gas on an energy-equivalent basis. That was before this year’s 30% hike in my electric rate, so it probably closer to 20 times now.

So your comment about costing less to operate will be true if the COP of the heat pump is 20 or higher. Maybe a bit less when considering the efficiency of my gas furnace.

 

[Jraef]

The last time I calculated, my electricity costs 16 times my nat gas on an energy-equivalent basis. That was before this year’s 30% hike in my electric rate, so it probably closer to 20 times now.

So your comment about costing less to operate will be true if the COP of the heat pump is 20 or higher. Maybe a bit less when considering the efficiency of my gas furnace.

Gas prices spiked around here a few years ago. Since going with solar, my electric bills are $10/month (basically the connection fee), but in winter, my gas bill jumps to $400/ month. I’m now supplementing my heater by using portable electric heaters during the day in the rooms we live in most of the time, that helps a little.

 

[mtnelect]

Gas prices spiked around here a few years ago. Since going with solar, my electric bills are $10/month (basically the connection fee), but in winter, my gas bill jumps to $400/ month. I’m now supplementing my heater by using portable electric heaters during the day in the rooms we live in most of the time, that helps a little.

Depending on the size of the PV system, it could cost between $25,000 and $55,000. Owners boast how much they are saving on their energy bill, without mentioning how much they paid for it. There are a lot of programs that help you pay for it, the worst one in California is "PACE" where it is tacked on to your property taxes.

 

[mtnelect]

Beware of offers of free solar systems.

 

[Jraef]

Depending on the size of the PV system, it could cost between $25,000 and $55,000. Owners boast how much they are saving on their energy bill, without mentioning how much they paid for it. There are a lot of programs that help you pay for it, the worst one in California is "PACE" where it is tacked on to your property taxes.

Mine was $32k, including the battery /inverter system. I used the $10k rebate to pay down the 1% loan (that was a requirement to get that rate), so my payments are $140/month, $1620/ year. I got a roughly $500 “true up” in each year since installing it, meaning the power I fed back into the grid was worth $500 more than what I drew from it. My prior electric bill was up to $400+ per month in spring though fall, but we never ran the AC unless it got to 90+ indoors, because it jumped to a LOT more if we did. That would be higher now because in 2 years we have had 2 price increases. So all in all it likely washes out; roughly $1.8k/year in added costs, (the loan plus factoring an amortized maintenance cost, which so far is zero), then between $1.7 and $2.3k per year in savings, depending on the weather-year. BUT I get to run my A/C in the summer and be more comfortable.

 

[retirede]

Depending on the size of the PV system, it could cost between $25,000 and $55,000. Owners boast how much they are saving on their energy bill, without mentioning how much they paid for it. There are a lot of programs that help you pay for it, the worst one in California is "PACE" where it is tacked on to your property taxes.

ROI calculations aren’t difficult. I’m currently helping a non-profit I volunteer at evaluate proposals for a solar installation. Getting all the data together is the hard part. Payback is looking like 5-8 years depending on factors.

 

[drcampbell]

... Getting all the data together is the hard part. ...

That, and having any confidence in the estimates of how long the equipment will actually last.
Likewise the companies building & installing it, who will be responding (or not) to warranty claims.

 

[mtnelect]

Mine was $32k, including the battery /inverter system. I used the $10k rebate to pay down the 1% loan (that was a requirement to get that rate), so my payments are $140/month, $1620/ year. I got a roughly $500 “true up” in each year since installing it, meaning the power I fed back into the grid was worth $500 more than what I drew from it. My prior electric bill was up to $400+ per month in spring though fall, but we never ran the AC unless it got to 90+ indoors, because it jumped to a LOT more if we did. That would be higher now because in 2 years we have had 2 price increases. So all in all it likely washes out; roughly $1.8k/year in added costs, (the loan plus factoring an amortized maintenance cost, which so far is zero), then between $1.7 and $2.3k per year in savings, depending on the weather-year. BUT I get to run my A/C in the summer and be more comfortable.

That is great information !

 

[gadfly56]

That's an old number. Current Mini-Splits will heat with the outdoor temperature down to -13°F. You can buy units designed for cold places that will heat with outdoor temperature down to -26°F!

It may achieve a COP greater than 1 at those temperatures, but what is the deliverable BUT/hr? All these systems have a performance curve, and if you design to keep pace with the heat loss at -26F, you may be way oversized (burning capital dollars) at 45F.

 

[gadfly56]

ROI calculations aren’t difficult. I’m currently helping a non-profit I volunteer at evaluate proposals for a solar installation. Getting all the data together is the hard part. Payback is looking like 5-8 years depending on factors.

Non-profits will find an additional hurdle, I think. Since they do not pay taxes, programs that tout tax incentives will be a non-starter for them.

 

[retirede]

Non-profits will find an additional hurdle, I think. Since they do not pay taxes, programs that tout tax incentives will be a non-starter for them.

Federal clean energy tax credits are refundable. Meaning you get the money even if you pay no taxes. Something I learned on this project.

 

[gadfly56]

Federal clean energy tax credits are refundable. Meaning you get the money even if you pay no taxes. Something I learned on this project.

I Googled this, and I see this is new with the Inflation Reduction Act of 2022.

 

[electrofelon]

Federal clean energy tax credits are refundable. Meaning you get the money even if you pay no taxes. Something I learned on this project.

I Googled this, and I see this is new with the Inflation Reduction Act of 2022.

So this would apply to the 27% (or whatever it is) federal tax credit for PV systems? So a nonprofit could utilize them?

 

[retirede]

So this would apply to the 27% (or whatever it is) federal tax credit for PV systems? So a nonprofit could utilize them?

That’s my understanding.