Live data from Hacker News

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

knowablemagazine.org

181–190 of 494 posts

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

#181
post #49

Sorry, but I don't see any novelty here. Everything described in the article is commercially available. At least here in Germany. Heat pumps are used to heat a storage container called buffer, a water container of 200l or more of water. This is used to run the heat pump when energy is cheap to warm up the buffer. That is for example in daytime when energy is available from the photovoltaic. If you don't have photovol…

This is like when Apple introduces some new feature that existed on Android for years and claims it as some sort of revolutionary thing. In this case it's just that the mainstream US has discovered heat pumps when they have been mainstream in Europe for many years.

Millions of people have used them for years. They just weren’t as popular due to gas being cheaper and available everywhere. There’s been a bigger push the last 10 years as gas prices have gone up. So they’ve been there but it didn’t make sense to use. You have to remember that things like gas are much cheaper in the USA. There’s just more natural resources here.

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

#182

Earlier quoted context omitted.

How do they affect the air quality indoors? Don't modern (less than fifty years old) gas boilers have balanced flues so that they take in air from the outside and exhaust the combustion products outside too? Surely properly installed gas boilers always did that even without balanced flues too.

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.

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

#183
post #168
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.

I have a sol-ark 12k which allows for grid isolation and a bunch of batteries.

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

#184
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.…

Why not install heated floors? That would be my choice in a new build.

It's expensive and it doesn't cool. Also doesn't circulate the air. I have some fancy filters and humidifiers as part of the system I'm putting in.

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

#185
post #69
post #57

Earlier quoted context omitted.

Different geographies have different requirements. You're not likely to need to face a week or more of no power after an ice storm in -10'C in Ireland.

We don't have power outages after ice storms. Temperatures of -10°C are regularly in Scandinavia as well as in Austria, Swiss and Germany. We are living in a developed world with working infrastructure. Power outages happens only by accident like when an US helicopter tries weird landings: https://www-abendzeitung--muenchen-de.translate.goog/bayern/...

Sure, as I said, different geographies have different requirements.

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

#186
post #134

Earlier quoted context omitted.

Agree, ducts are wonderful! If you don't have ducts, go ductless for sure.

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.

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

#187
post #79

Earlier quoted context omitted.

I always joke that in winter all appliances are 100% efficient (I know they're not). Some look at me funny but the ones who pay the gas bill get usually get it.

If you have a resistance electric furnace, that is essentially true. With gas, you add the electric generation and distribution losses, which is a pretty big difference. It does cost more to run an appliance than to heat with gas.

If you account for the electric generation and distribution losses, you should do the same for gas.

"It does cost more to run an appliance than to heat with gas."

That's highly dependent on the appliances involved and the price you pay for each fuel. For me, a heat pump is much cheaper to run. You really need to calculate it for each individual situation.

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

#188

Earlier quoted context omitted.

Happy in some times, unhappy in others. There are days I'd love if the A/C would have a humidifier built-in, for those winter months when you might want to use A/C to warm the interior.

A good chunk of the United States (and a number of other countries) uses forced air natural gas heating. If you fall into that group, you can install a "whole-house humidifier" that injects steam into the hot air plenum, distributing it around the house. This makes the air less dry (obviously) but also has the side-effect of actually reducing the need for heating because air holding moisture feels warmer than air wit…

The moisture can promote mold in the ductwork though. We had our furnace replaced a few years ago and had the central humidifier removed. The interior of the ductwork was black with mold near the humidifier so that was also replaced.

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

#189
post #132

Earlier quoted context omitted.

> Ducts are dead. Ducts are still needed to circulate air, especially if you want to remove stale air (e.g., bathrooms, kitchen) and bring in (filtered) fresh air (to bedrooms).

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.

I used to have a bathroom without an extractor and in the winter with the window open the cold air would just cool the walls and cause more condensation there than I’d get with it closed.

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

#190

Earlier quoted context omitted.

Unless you have a very strange setup, centralized A/C does not have humidity sensors nor run just to dehumidify. Nor does removing humidity increase the load on the A/C system. Removing humidity is just a happy by-product of how centralized A/C works. So no, you would not be increasing load for that reason.

Happy in some times, unhappy in others. There are days I'd love if the A/C would have a humidifier built-in, for those winter months when you might want to use A/C to warm the interior.

One of the Daikin models for Japan apartments/condos (known as mansions) has a tankless humidifier; it is able to condensate humidity from outdoor air and introduce it into the home. On a cold winter day it is able to raise the relative humidity from around 30% to about 45% or so. うるるとさらら is the name of their series of things that humidify.
Post reply on HN