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Heat pumps of the 1800s are becoming the technology of the future

knowablemagazine.org

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Re: Heat pumps of the 1800s are becoming the technology of the future

#351

Post by fifteenforty »

EricE wrote: post #335
fifteenforty wrote: post #269

Earlier quoted context omitted.

The no 1 reason I bought the Daikin model referenced over the comparable Mitsubishi Electric is that it has the ‘MOULD PROOF’ function. It runs the fan automatically after you have had it in cooling mode, to evaporate the moisture build up from the interior condenser coil, thereby removing the moisture required for the growth of bacteria and mould. So far, it seems to be working! Better than relying on everyone to ma…

If you live in any kind of area with high humidity you just shifted the mold from the AC unit to the rest of your house. Hell even here in the desert I'm not sure I'd want to use that "feature".

We are talking about the tiny amount of water vapour left on the interior condenser. The idea is to bring that back up to room temperature so that it doesn’t stay there near the dew point. The total amount of water inside the house does not change!

Re: Heat pumps of the 1800s are becoming the technology of the future

#352

Post by fooqux »

bumby wrote: post #243
Brybry wrote: post #199

Earlier quoted context omitted.

I don't think the hardware is that expensive in the US, it's the installation (which costs more than the hardware). And mistakes by installers will cost even more. Our installers didn't flare a line set connection properly and it leaked slowly and that was a very expensive bill (especially since refrigerants have changed so much). Our Daikin indoor units have also had condensate leaking issues, probably due to poor i…

> And mistakes by installers will cost even more. I once looked at a house with a new GSHP horizontal loop installed in the desert southwest US. I talked to the installer and they said the loop was only 12” deep. There’s no way the ground maintains steady temp at that depth, meaning you’re losing efficiency in the hot months when you need it most. Not to mention thermal pollution which will exacerbate the problem and…

Twelve inches? If that's true it seems like it would get ruined quickly by roots, animals, vehicles, lawn mowers, and basically everything else.

Re: Heat pumps of the 1800s are becoming the technology of the future

#353

Post by Dylan16807 »

EricE wrote: post #338
Dylan16807 wrote: post #227

Earlier quoted context omitted.

The average temperature sure. But would uneven spots have that much effect on the thermal radiation I get sitting over a meter away?

Less that 2% of insulation being out of place can waste something like 40% or some ridiculous amount of energy. It's quite nuts how even just a little break in insulation can have a significantly negative effect. A few years after I moved into my first home - a townhouse - I added some R-16 bats to the already existing R-12 insulation in the attic and it more than cut my heating bill in half. It was a three story nar…

Okay but that's not what I was asking. That much heat loss will affect the overall temperature.

Re: Heat pumps of the 1800s are becoming the technology of the future

#354

Post by Danieru »

jonplackett wrote: post #312

> Lord Kelvin proposed using heat pump systems for space heating way back in 1852. The first heat pump was designed and built a few years later That’s the kind of speed we need if this is going to be any help before everything’s on fire anyway. From what I can tell (in / for the UK at least) heat pumps currently aren’t that great - my dad’s boiler just died and every plumber he spoke to said heat pumps kinda suck and…

"I talked to a bunch of horse tamers and they say cars are just no good. So I bought another horse. I don't see all the hype"

Similar issue in the states. HVAC specialist trash talking mini splits because a mini split's advantage of cheaper maintenance and install is meaningless to the HVAC specialist. Instead they only see the trade offs. Then they quote a bill as if installing a mini split requires a diploma and point out just how uneconomical the farce is.

Re: Heat pumps of the 1800s are becoming the technology of the future

#355

Post by Godel_unicode »

throwawaylinux wrote: post #279
jimmaswell wrote: post #238

Earlier quoted context omitted.

That thing's an eyesore compared to a duct to me.

They're noisy too. Not loud, it's a quiet hum, but it's annoying if that annoys you, some people are sensitive to noise. The system I have doesn't seem to have a variable-output control, so it uses an on/off hysteresis that drives me up the wall. I could deal with a constant hum, but the stop start every minute or two is annoying. A previous house I lived in the ducts were absolutely silent unless it was on high you…

They’re not even less efficient if installed correctly, it just takes some thought and some insulation. And you get really good filtering with very low likelihood of mold in the bargain.

Re: Heat pumps of the 1800s are becoming the technology of the future

#356

Post by Godel_unicode »

nostrademons wrote: post #174
phyzome wrote: post #144

> owners of drafty homes may need to take on the added cost of insulation when installing a heat pump Installing good insulation is also really important even if you're not using heat pumps! With bad insulation, you're wasting energy no matter what technology you're using.

I've heard folks who work in the home energy audit business say that upgrading insulation is usually the most cost-effective thing you can do to lower energy bills. Even better, it's multiplicative with other activities like installing heat pumps or solar, so you can install a much lower capacity system and still hit your energy targets.

And in the United States at least, the IRA contains tax incentives for all of that. The audit, the added insulation, the heat pump, and even more efficient appliances.

Re: Heat pumps of the 1800s are becoming the technology of the future

#357

Post by buildsjets »

hawaiianbrah wrote: post #307
IAmGraydon wrote: post #232

Earlier quoted context omitted.

Are you asking why the Daikin Alira X is more expensive in the US? It's because it's not a brand that is normally found here. If you went with a common US brand you can get a good system with 4 units and a 36,000 BTU heat pump unit for around $6,500 USD installed. I don't love the wall units - they're pretty ugly, even the new ones. If you're getting a mini-split, the in-ceiling or wall cassettes that are hidden are…

Wow, really? Prices seem much higher than that in Seattle. A friend got 3 handlers totaling 24k BTU for like 12 grand.

I got quoted 16 grand for the same 24k/3 zone system in the Seattle area by the guys who install thru COSTCO. I ordered the hardware myself for $4300, bought about $300 worth of tools, and installed it in one long weekend. It’s really not that difficult. Basic electric installation, some special technique and tools needed for the plumbing (University of Youtube can help), pressure test, pull vacuum, open the valves and enjoy.

https://www.ecomfort.com/Fujitsu-F3H24W07071200/p65952.html

Re: Heat pumps of the 1800s are becoming the technology of the future

#358

Post by hawaiianbrah »

buildsjets wrote: post #357
hawaiianbrah wrote: post #307

Earlier quoted context omitted.

Wow, really? Prices seem much higher than that in Seattle. A friend got 3 handlers totaling 24k BTU for like 12 grand.

I got quoted 16 grand for the same 24k/3 zone system in the Seattle area by the guys who install thru COSTCO. I ordered the hardware myself for $4300, bought about $300 worth of tools, and installed it in one long weekend. It’s really not that difficult. Basic electric installation, some special technique and tools needed for the plumbing (University of Youtube can help), pressure test, pull vacuum, open the valves a…

I’ve been eyeing https://mrcooldiy.com/, even easier.

Re: Heat pumps of the 1800s are becoming the technology of the future

#359

Post by fifteenforty »

throwawayacc3 wrote: post #346
operatingthetan wrote: post #176

Earlier quoted context omitted.

Good callout. Some people have the strangest reasons to hate high-efficiency ductless systems.

Except it's incorrect. The best system is a "ducted ductless" system that circulates and filters air throughout the house.

I've seen that terminology used on US websites, it took me a while to get my head around. In Australia it would just be called ducted reverse cycle. In the vast majority of cases it would be "ducted ductless" I guess: outside unit connects via refrigerant lines to a heat exchanger and fan in the roof cavity, when then distributes the heated/cooled air to rooms via conventional ducting.

Re: Heat pumps of the 1800s are becoming the technology of the future

#360

Post by abakker »

elil17 wrote: post #182
abakker wrote: post #173

Earlier quoted context omitted.

My experience (sample of one) is that they don't. They're supposed to, but VOCs are definitely higher all winter running heat than all summer running air conditioning. Natural gas combustion is at best _mostly_ exhausted.

It could also be that outdoor AQ is worse around you in the winter because everyone is running their boilers, and then that outdoor air ends up inside. I can't test it because I have a heat pump, but I would be curious to know what happens to your VOCs if you turn off your boiler at a time when your neighbors are still running theirs.

My meter here in boulder, CO reads effectively 0 VOC outdoors all year round.
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