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

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

#61

Post by JustSomeNobody »

jdmichal wrote: post #37
ballenf wrote: post #28

Earlier quoted context omitted.

I've often wondered if opening windows while AC is running and outside temp is below inside temp is less efficient than keeping them closed. My thought is I should keep them closed due to extra load on the AC to dehumidify the outside air. Or open windows and turn AC to fan-only mode to prevent stagnant air in rooms without windows.

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.

My thermostat allows me to set the humidity level at which it will turn on the A/C to deswampify my southern home.

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

#62

Post by ComputerGuru »

sampo wrote: post #21
dabeeeenster wrote: post #13

Earlier quoted context omitted.

Just had a heat pump installed (Vaillant) - at -1 degrees outside I'm getting a COP of > 2.6. So they are ready.

> -1 degrees outside -1F is -18C -1C is 30F

They're from London, so it's the "not even cold but it's negative" rather than "actually cold and heat pumps aren't a good idea" measurement.

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

#63

Post by tshaddox »

ghettoCoder wrote: post #16
retrac wrote: post #10

Earlier quoted context omitted.

> it seems crazy that I warm the air of my house and then use electricity to keep the fridge cooler than the air I just heated The fridge is simply moving a little of the warmth in your room out of its box, and adding a little more warmth to the room in the process. You lose no heat from the room, which is what matters, really. It would be worse to dump the heat outside! At least in winter. The heat has to be removed…

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.

“100% efficient” doesn’t tell the whole story of the gas bill if you’re heating your house with something cheaper than electric heat (e.g. natural gas).

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

#64

Post by Volundr »

grey-area wrote: post #36
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…

I know a couple of people who rely on a ground source heat pump without a backup in Europe. They also both have induction hobs as it happens!

The induction comment was weird. I went from electric to induction a few years ago, and it's not life changing or anything, but it works reliability. I suppose it's faster, but for me the main benefit is it makes it much harder for me to accidentally leave a burner on and burn my house down.

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

#65

Post by nagisa »

macinjosh wrote: post #30
jakedata wrote: post #19

In 2017 we installed a very efficient air-source heat pump and solar panels. My electrical utility offers 1:1 buyback of electricity so I am able to build up a credit in the summer and run the heat pump well into the fall and winter on that surplus. The system is sized for cooling the house which means that it is undersized for heating, but during cool fall and spring temperatures it operates satisfactorily as a heat…

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…

I’ve a 6kW nominal, ground-source heat pump as the only heat source. This is a well insulated building standing atop the soil of a European country with a temperate climate*. It does a great job at +35°C (passively cooling) and just as great at -35°C.

During installation we've even made a mistake and it heated the building up to something like +27°C inside during early winter all without breaking a sweat (or my wallet.)

The tech is ready. Many attempts to apply it is what’s getting botched.

* EDIT: having checked, most of europe falls within temperate – the country is up north.

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

#66

Post by PinguTS »

macinjosh wrote: post #30
jakedata wrote: post #19

In 2017 we installed a very efficient air-source heat pump and solar panels. My electrical utility offers 1:1 buyback of electricity so I am able to build up a credit in the summer and run the heat pump well into the fall and winter on that surplus. The system is sized for cooling the house which means that it is undersized for heating, but during cool fall and spring temperatures it operates satisfactorily as a heat…

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…

Its always funny reading such comments while others are running for years their heat pumps without any problems needing a backup.

Not only they are used in Scandinavia for years. Also in Germany they are used for years. The company Waterkotte operates since the 1980s in Germany and is a pioneer in this showing it is working.

But there are always people ignoring the facts.

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

#67

Post by tshaddox »

jdmichal wrote: post #37
ballenf wrote: post #28

Earlier quoted context omitted.

I've often wondered if opening windows while AC is running and outside temp is below inside temp is less efficient than keeping them closed. My thought is I should keep them closed due to extra load on the AC to dehumidify the outside air. Or open windows and turn AC to fan-only mode to prevent stagnant air in rooms without windows.

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.

Based on some of the home building and HVAC videos I’ve seen on YouTube, it seems pretty common for high-end new home construction in the U.S. (especially the south) to have separate AC and dehumidifier units.

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

#68

Post by rainsford »

Volundr wrote: post #59
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…

Define backup? I have a heat pump as my only source of cooling/heat, but it does have a single heat strip in it for the couple days a year it gets too cold for the heat pump alone. There no "second fixture" to maintain. This is common for my area.

Same for where I live. And in fact it's arguably a simpler setup since where I live you also need air conditioning in the summer, so many homes already have 90% of what they need for a heat pump setup (which is after all just an AC running in reverse). Installing some other heat source alongside the AC you already have instead of just installing a heat pump for year round needs is arguably the more complicated option.

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

#69

Post by PinguTS »

poutine wrote: post #57
rsynnott wrote: post #41

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. Eh? Most new houses in Ireland have them these days (it's more or less the only way to meet the efficiency requirements). There's never a backup. > Same thing for induction stoves. Eh? Again, these are pretty standard these days, and why would you need a backup?

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/...

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