Page 24 of 24

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Mon Feb 07, 2022 4:59 pm
by dmacarthur
And it certainly showed in their proposals: most of the local companies proposed systems that were obscenely oversized based on the actual heating load. Our heating load for a 99% outdoor design temp of 11F is around 30,000 btu/h, but most of the "elite" and "diamond" Fujitsu and Mitsubishi contractors were trying to sell me on 48,000 - 70,000 btu/h systems.
Agree with this- it is time-consuming but productive to do your own heat loss calculations because it is my suspicion that contractors do a quick run-through and then multiply by about 2 to be sure. So do your own, carefully, and stick with it, adding maybe 20%.....

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Fri May 13, 2022 4:24 pm
by LeftieBiker
It looks like our central A/C unit is dying. It and the furnace are both over 20 years old, IIRC, so I'm reluctant to throw money at it. Can anyone point me to a good, honest, reasonably priced heat pump installer in the Albany - Saratoga Springs NY area? I've been trying to talk my housemate into getting a good air source heat pump that will provide enough heat down to 0F or so. It would probably have to have a backup furnace for her peace of mind, and that furnace would have to be either electric or oil -she's terrified of gas. I'm willing to put in $5k, so it would have to be in the $15k range, installed. I am no longer able to do this kind of work.

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Fri May 13, 2022 5:09 pm
by LeftieBiker
Update: the issue isn't, as I at first thought, a refrigerant leak. For some reason the outdoor A/C unit tripped its breaker, leaving the system blowing cool air just because the ducts pass through our chilly cellar. I reset the breaker, and now it's running more or less normally, blowing cold air. This is the first time, though, that it's done that, so I'm guessing it won't be the last.

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Sat May 14, 2022 9:42 am
by dmacarthur
I've been trying to talk my housemate into getting a good air source heat pump that will provide enough heat down to 0F or so. It would probably have to have a backup furnace for her peace of mind,
We run heat pumps in one rental unit which have reliably heated with no backup for 3 years in Vermont- it is a Fujitsu unit but others are probably by now able to provide heat at well below zero. I know this does not ease the "peace of mind" issue but..... it can work!

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Sat May 14, 2022 10:05 am
by SageBrush
dmacarthur wrote: Mon Feb 07, 2022 4:59 pm
And it certainly showed in their proposals: most of the local companies proposed systems that were obscenely oversized based on the actual heating load. Our heating load for a 99% outdoor design temp of 11F is around 30,000 btu/h, but most of the "elite" and "diamond" Fujitsu and Mitsubishi contractors were trying to sell me on 48,000 - 70,000 btu/h systems.
Agree with this- it is time-consuming but productive to do your own heat loss calculations because it is my suspicion that contractors do a quick run-through and then multiply by about 2 to be sure. So do your own, carefully, and stick with it, adding maybe 20%.....
The story I've heard is that installers have two big reasons to oversize:

1. Bigger installs mean more profit
2. It would be a rare post-installation call complaining of poor efficiency (and it would be easy to deflect the blame) but woe to the installer who gets a call complaining that the system is inadequate to keep the house at the desired temperature. Merkins are their own worst enemy.

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Sat May 14, 2022 10:16 am
by LeftieBiker
We run heat pumps in one rental unit which have reliably heated with no backup for 3 years in Vermont- it is a Fujitsu unit but others are probably by now able to provide heat at well below zero. I know this does not ease the "peace of mind" issue but..... it can work!
Thanks. It isn't as if we couldn't run electric space heaters if needed - we do that now. If I can succeed in convincing her to delete the fossil fuel furnace, then we can probably afford a good heating system. The issue then becomes mating an air source heat pump with our hot air duct work. Or going back to trying to find a contractor who will install a heat pump in tandem with our existing oil furnace...

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Thu Jul 07, 2022 8:13 am
by bmw
I didn't see any other mention of solar heating except for opening shades. We have what we call a solar green house and two Sunmate solar heating panels. Together they supply between 30% and 50% of our heating. We also have insulated shades on most of our windows that more than double the R-value of double pane windows. By the way we also have photo voltaic panels on our roof (installed after the heating panels). They supply enough electricity to cover all of our electrical usage including for our Nisan Leaf.

Here are two links to what we have.

http://photosbybmw.com/Tutorial_pages/solar_heat.html

http://photosbybmw.com/Tutorial_pages/w ... ation.html

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Thu Jul 07, 2022 9:45 am
by goldbrick
Put in a whole house fan last night. I completely removed the AC last fall in anticipation of getting some sort of heat pump system but that project could be a year or two out so hopefully the fan will work in the meantime.

We always open the windows at night since the temp here in CO cools off nicely nearly all the time at night. The exception would be if it is cloudy but in the summer, clouds usually mean rain or a cold front has just passed through.

I put in a QuietCool ES-4700. It is on the large side for our sq.ft. but I read that running a larger fan on a lower setting is better than vice versa. I didn't bother putting in a timer and just ran the fan on low for about 6 hours. It's quiet and I'd say it's about as noticeable as having a dishwasher running in the distance. Ie, if you listen for it you can detect it but it probably won't keep you awake.

I installed it myself and the hardest parts were maneuvering around the attic with the blown-in insulation and trying to figure out the incredibly poor wiring instructions.

I also had to install 4 new gable vents to provide adequate exhaust flow but that was pretty straightforward. In fact, just doing that probably helped quite a bit since as soon as they were in I could feel the super-heated air from the attic flowing through them. I do have roof vents and some soffit vents but the the total equivalent vent area of those is probably just a few square feet.

Re: Share Your Home Electrification/Efficiency Improvements

Posted: Fri Jul 15, 2022 8:55 pm
by goldbrick
I just ordered 8 more (325W) panels today since Unbound Solar had a 'garage sale'. That should add about 40% to my existing array. I'll have to increase my usage before my utility will let me install them.

The overall cost/watt will be much lower this time since a lot of the infrastructure is already in place and I know what is needed so I don't have to buy a 'kit' but can shop around for the best prices on the various components.