TIL heat pumps weren't invented in the last few years
Heat pumps of the 1800s are becoming the technology of the future
91–100 of 494 posts
Re: Heat pumps of the 1800s are becoming the technology of the future
#92Why can’t my whole home participate in this technology? It would seem an ok fit for things like freezers, refrigerators, hot water heaters, etc. When it’s freezing cold outside, 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. Someone needs to make a standard for moving heat/cool through all appliances in a house…
I think you are going to like section IV of:
Re: Heat pumps of the 1800s are becoming the technology of the future
#93Earlier 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.
Is the AC dehumidifier an extra feature/task, so actively followed, or is it doing dehumidification just as a byproduct happening while cooling?
Some AC units have two modes - cooling and dehumidifying. When in cooling mode it will blow a lot of air to keep evaporator as hot as possible, so less humidity is condensing on it (but there will still be some). In dehumidifying mode it will blow less air but keep evaporator cool, so more condensation for the same amount of air cooling.
Re: Heat pumps of the 1800s are becoming the technology of the future
#94Earlier 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.
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Re: Heat pumps of the 1800s are becoming the technology of the future
#95Earlier quoted context omitted.
The fridge isn't the biggest energy hog in the house, but I'm very sympathetic to the absurdity of heat levels in a house. I often see my HVAC cooling when the set-point temperature is actually _higher_ than the outside temperature. Logically, the house is a heat generator, it makes sense physically. The roof is black, etc. It would offer a good number of benefits if the system could outright open a duct to the outdo…
I've built/retrofitted and a prototype of mechanically operated louvres with push/pull fans for air exchange in an old school building, tied to the thermostat, ac, and a CO2 detector. The idea of doing the same in my home has been taunting me for years now. Ideally you'd have two such louvres, one with a push fan in the upper floor and the other with a pull fan in the lower floor to simultaneously eject unwanted heat…
I was thinking a big vertical heat pipe that sticks out like a chimney would be great for this and keep inside+outside sealed.
When it’s colder outside, liquid will evaporate on the bottom and condense at the top through gravity. Once it’s warmer outside, the whole process just stops.
No valves, no pumps, no analog or digital controls. Ok, maybe a fan.
I actually want a fridge/freezer at the cabin that works like this in fall/winter/spring. I know it’s technically moving heat from inside to outside, but I’ve got more wood than electricity to work with.
Re: Heat pumps of the 1800s are becoming the technology of the future
#96Earlier quoted context omitted.
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…
I had one that dripped water through a pad in air flow, and had a small drain pipe. Maybe not as good as steam, though much simpler.
The ones I’ve seen have a rotating foam drum pad in a small reservoir of water that refills like a toilet tank.
Re: Heat pumps of the 1800s are becoming the technology of the future
#97Why can’t my whole home participate in this technology? It would seem an ok fit for things like freezers, refrigerators, hot water heaters, etc. When it’s freezing cold outside, 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. Someone needs to make a standard for moving heat/cool through all appliances in a house…
> 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…
The smart thing to do in winter is put municipal liquid water in your freezer, and dump it outside once frozen to thaw in spring. Rince repeat all winter long.
Voila: everyone has heat pump heating! (And dead compressors).
The dumb thing is having the compressor itself indoors in summer. Should be outside.
Re: Heat pumps of the 1800s are becoming the technology of the future
#98Why can’t my whole home participate in this technology? It would seem an ok fit for things like freezers, refrigerators, hot water heaters, etc. When it’s freezing cold outside, 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. Someone needs to make a standard for moving heat/cool through all appliances in a house…
There are heat pump water heaters (I have one; AO Smith HPTU-50N). More expensive up front vs tankless but a lot more efficient.
Depends on usage. Tankless efficiency really shines with irregular use.
Keeping a big reservoir warm for the sake of keeping it warm only becomes efficient with regular usage.
Re: Heat pumps of the 1800s are becoming the technology of the future
#99In 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…
Since your natgas consumption is low, could a wood pellet heater meet your needs instead of natgas?
I guess it depends if your natgas bill has a big fixed cost (and I guess you’ve already covered the sunk cost of connection…)
Re: Heat pumps of the 1800s are becoming the technology of the future
#100Earlier 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/...
Or a crane barge not making it under the power lines overhead:
https://www.cbc.ca/news/canada/toronto/hydro-one-downtown-po...