Maybe "super-cold" ASHP will never be a thing ?

archibald tuttle

Dave Carpentier said:

Everything above ambient will be bleeding btu into the structure, generally afaik the closer to ambient it is, the slower the bleed.

is there a secret to getting those quote snippets. i try selecting the text i want and clicking quote and i still get the entire post and then I have to delete everything except the desire quote and the correct bits of html. @Erin Holohan Haskell

@Dave_Carpentier
i think that is right but the point @Hotrod was making is that the bleed is so slow under 90 as to lack appreciable transfer. now in superinsulated circumstances, all bets are off . . . eer on. And I absolutely believe you can do better spending money on insulation (which also has to be done right: my bible ) before you spend it on heating technology. Doing insulation right is damn expensive as well, both in materials and opportunity cost in detailing, but the payback usually looks better.

PC7060

JakeCK said:

I legit just LOL'd when I seen the concrete dog. 

Beagle right?

The radiant dog is pretty cool but can’t imagine getting planning approval from the residential planning supervisor.    @hot_rod must have a very understanding wife!   

hot_rod

PC7060 said:

JakeCK said:

I legit just LOL'd when I seen the concrete dog. 

Beagle right?

The radiant dog is pretty cool but can’t imagine getting planning approval from the residential planning supervisor.    @hot_rod must have a very understanding wife!   

Only one of my radiant projects fell flat with me wife. I installed this exposed radiant ceiling when she was out of town. Even the flat white paint and white MultiCor couldn't hide the fact it was up there. It was very comfortable

One of the extruders for ThermoFin was near me and I went down and got extra long plates hot off the press.

Dave Carpentier

archibald tuttle said:

is there a secret to getting those quote snippets. i try selecting the text i want and clicking quote and i still get the entire post and then I have to delete everything except the desire quote and the correct bits of html.

Edit the reply's html bits. A quote starts with < blockquote class="Quote" > and ends with < /blockquote >. Note that I added spaces by the < 's so that it wouldnt actually do it now.

Solid_Fuel_Man

hot_rod said:

Only one of my radiant projects fell flat with me wife. I installed this exposed radiant ceiling when she was out of town. Even the flat white paint and white MultiCor couldn't hide the fact it was up there. It was very comfortable One of the extruders for ThermoFin was near me and I went down and got extra long plates hot off the press.

She didn't like the um.....coffer'd look? 

My wife may or may not have some similar stories of what appreas to have happened when she is away....

Erin Holohan Haskell

archibald tuttle said:

Dave Carpentier said:

Everything above ambient will be bleeding btu into the structure, generally afaik the closer to ambient it is, the slower the bleed.


is there a secret to getting those quote snippets. i try selecting the text i want and clicking quote and i still get the entire post and then I have to delete everything except the desire quote and the correct bits of html. @Erin Holohan Haskell

@archibald tuttle, everything that will be in the quote will be between the blockquote tags. You can click the Quote button and then edit what appears between these tags to shorten it. PM me if you have more questions about this. Thanks!

ronaldsauve

Hot_water_fan said:

Another idea nobody ever talks about is dual source heat pumps. Air most of the time and geo or water for those cold days. 

You run into the same heating degree day distribution problem - few days are beyond the capabilities of air source, so spending $$$ for a handful of days makes less sense than better insulation, storage, solar, hybrid backup, etc. Using a water source heat pump with ice would be interesting to me, but probably not economic at all. 

ronaldsauve

I agree with Hot_water_fan. We’re not in a -20 zone, we’re in Maine, with an existing 1300 sq ft ranch with full basement, facing southwest. But the first priority for us was air sealing and insulating, which at the time in the late 90’s was well beyond code. But as I’ve always stressed to customers, “think at least 20 or 30 years out” because energy costs aren’t going to go down. Granted, I did all of the work included in this entry myself, so contracting it would be more costly, but it still is cost effective over the long haul. So I air sealed to the extreme, and I did R-70 in the attic space, and an effective R-32 in walls, including basement walls, “effective” including framing, with continuous rigid polyurethane for the entire envelope. I only did Andersen casements, because truly high performing windows at the time were hard to find. And I did stock insulated fiberglass doors, and high quality storms. We already had a low mass oil fired boiler, with 2 hot water tanks, one for domestic, and one for the radiant floors throughout the house. And it worked fine. Then I added a Mitsubishi 9000 btu 33.1 SEER Minisplit rated to -13° with no pan heater, and used only that for heat through the winter, except on the coldest below zero days, when I turned on the radiant floors. The next year I added another Mitsubishi 6000 btu 33.1 SEER Minisplit rated to -13° with no pan heater, and removed the whole boiler system. I added a Sanden Minisplit for HW. By this time we had an all electric house. So last year, I designed and installed a 15 kw solar system, with adjustable ground mount and roof mounted panels. Now we’re generating 20,000 kWh a year, at least 5,000 more than we’re using. We have no electric bill, no heating bill, and no cooling bill, and we are very comfortable. And we’re considering an electric car which will use some of the excess generation. So, bottom line: first plug the leaks in the bucket. It makes no sense to have to buy the most efficient, but larger HVAC system that needs maintenance and eventual replacement years down the line, if all it’s doing is working overtime to keep up with the leaks, and we’re still not truly comfortable, with the inevitable drafts. If we first plug the leaks, we’ll only need a much smaller HVAC system that costs far less to operate, and we’ll have a draft free comfortable home.

pavalenta

JakeCK said:

Speaking of a2w heat pumps does anyone have any experience with those Arctic heat pumps or has seen one in the wild?

I have a MBTek unit which is really Phnix-e out of china, SpacePak does or used to have a system by the same OEM, Artic sells Phnix-e Fan Coil units. I'm still waiting on AHUs to replace my furnace but my overall plan is for radiant heat in my basement slab with a High Wall Fan Coil for supplemental and then replace whole home furnace with a AHU for heat and AC. So far it's working well but I haven't had a heating season with it, currently chilling my basement slab with it. Their manual for the units has a rather extensive heat capacity, power required and COP chart, all depends on outlet water temp commanded.