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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

#221

Post by nerdbert »

pinot wrote: post #168
poutine wrote: post #53

Earlier quoted context omitted.

Living in the PNW, I'm building a new house and I've chosen a dual fuel hybrid heat pump system as per https://www.bryantbing.com/products/hybrid-heat/ I'll also have solar + battery. Should be able to run the furnace & fan but not the heat pump (too many kW/h) during a power outage and thus heating with gas. It'll run off the heat pump for 90-95% of the year, only using gas on the coldest days, or during an outage.…

Can't heat with gas without electricity, unless you have a genset or power wall kind of thing to provide epower.

Until a couple years ago we had a gas-fired tankless water heater which used a single D-cell battery for ignition, which had to be changed once every year or two. It wasn't connected to wall power at all.

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

#222

Post by Karupan »

fifteenforty wrote: post #216
Karupan wrote: post #212

Earlier quoted context omitted.

I got a similar setup for my house as well. Being able to selectively cool rooms that are in use is great. However, I do wish the insulation was far better. Unfortunately I’ve noticed that Melbourne houses are usually very poorly constructed due to expensive raw materials and labour.

Have you examined your insulation with a thermal camera? Might be worth your while to get an energy inspector out. Personally I haven’t yet, mostly because I can still see low hanging fruit to fix.

Yea have some pretty obvious improvements pending as well. But that’s a good suggestion - might get someone to come give a professional assessment before I put in a 7kwh unit for another room.

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

#223

Post by TheSpiceIsLife »

kccqzy wrote: post #204
mvnuweucxqokii wrote: post #163

Earlier quoted context omitted.

Not to be snarky, but if the weather outdoors is uncomfortable enough to be using climate control, why would I want to open the window?

Because presumably in this case you would want to open a window for fresh air, and simultaneously run your heating system to heat up that fresh air? I was responding to a comment that presupposes the need for fresh air. If you don't need that, feel free to close the windows then.

Airborne allergens can be an issue, and dust more generally.

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

#224

Post by nerdbert »

tomohawk wrote: post #124
macinjosh wrote: post #30

Earlier quoted context omitted.

Still waiting for one of these people who rave about their heat pump system to actually rely on it full time without a backup. Most folks could barely afford to replace an existing furnace in a place that has all the fixtures installed, much less pay to install a second one based on different setup, and then pay for maintaining two systems on top of everything else. It is absurd to think that this is a plausible way…

The article is light on technical details, pointing to a heat pump vendor site for "proof" that they're great. I live in a heavily populated area with high standard of living, and yet we have had power outages lasting up to a week in the years we've lived here. Almost all in the winter, but also some due to hurricanes. We have have solar, which is great in the summer heat, but not as wonderful in the winter. We have…

> I live in a heavily populated area with high standard of living, and yet we have had power outages lasting up to a week in the years we've lived here.

Maybe you are in the USA? The infrastructure situation seems to be different there. We don't have any above-ground power lines in this country (except for high-voltage long-distance transmission trunks) and in the past ten years the power has gone out exactly twice, according to my uptime logs - once for 40 minutes and once for about three hours.

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

#225

Post by gautamdivgi »

jimmaswell wrote: post #151
fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

> Ducts are dead. How do you move the heated/cooled air into/around the house without ducts?

How would it behave in a place like Chicago where we've had recent weather events that take the temperature from 40F to -10F in a couple of days? Will the system catch up that fast without ducts?

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

#226

Post by OJFord »

mvnuweucxqokii wrote: post #163
kccqzy wrote: post #132

Earlier quoted context omitted.

Not being snarky but why don't you just open the window for that? I have a CO2 detector that I believe is a reasonable proxy for stale air. When it goes above 1000 I simply open the windows. By the time I remember to close the windows the reading is almost always below 500.

Not to be snarky, but if the weather outdoors is uncomfortable enough to be using climate control, why would I want to open the window?

For the fresh air that this thread is about, regardless of whether it comes through a glazed window or a duct connected directly to AC system?

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

#227

Post by Dylan16807 »

fifteenforty wrote: post #215
metadat wrote: post #198

Earlier quoted context omitted.

Honest question: Why would one care about cold or hot spots on the ceiling? I don't spend much time up there.

Approximately 70% of the heat loss from your body is as radiated heat. Ceiling insulation is critical for thermal comfort. Have a look at the Efficiency Matrix YouTube channel videos on insulation consistency.

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

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

#228

Post by thehappypm »

Brybry wrote: post #199
fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

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…

Daikon is way worse than Mitsubishi from what my hvac guy tells me

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

#229

Post by notyourwork »

aftbit wrote: post #186
code_biologist wrote: post #136

Earlier quoted context omitted.

Am I crazy, or are those two sentences completely contradictory?

I read it as: Ducts are better but not so much that it's worth tearing everything apart to install them. If you don't already have ducts, you should definitely use a ductless system. If you do have them, you get some other benefits.

Ducts are great with a heat pump and an air handler with variable fan speed.

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

#230

Post by Dylan16807 »

krageon wrote: post #143
code_biologist wrote: post #136

Earlier quoted context omitted.

Am I crazy, or are those two sentences completely contradictory?

I thought it was a joke. If you don't have ducts, you are by definition ductless. So that's how you must go.

> So that's how you must go.

No, you can go to ducts by installing them. I believe the comment is advising against doing so.

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