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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

#71

Post by blacksmith_tb »

phkahler wrote: post #35
nickpeterson wrote: post #4

Why 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…

The fridge is heating your home, so that reduces the burden on whatever is heating your home. The coil on the back gets hot.

Note that this is only an advantage in cooler months, and does work against cooling your home in hotter weather. In principle it seems like we could could build our refrigerators into an outside wall (like iceboxes once were) and then expose the coils in summer, and enclose them in winter.

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

#72

Post by Tijdreiziger »

ComputerGuru wrote: post #51
AlanSE wrote: post #22

Earlier 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…

What would the upside be over a standard heat-exchanging mechanical ventilation system?

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

#73

Post by rini17 »

PinguTS wrote: post #69
poutine wrote: 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/...

There are occassional outages. But the pylons are designed with icing in the mind and that does the difference. More outages are due to poorly trimmed trees falling on wires than ice itself. That usually affects only small area and can be fixed quickly.

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

#74

Post by elil17 »

zozbot234 wrote: post #12
retrac wrote: post #2

> heat pumps: electrical devices Just to be pedantic, but not exactly. The typical design in a domestic heating unit, or refrigerator is mechanical. A fluid is pumped and cyclically compressed/expanded. While electric motors are usually used, they can be driven by any source of mechanical energy; driven directly by a combustion engine is not too unusual. There are also heat pump cycles that can be driven directly wit…

Strictly speaking you don't need a phase change in the fluid for a viable heat pump; pressure change is enough albeit with worse efficiency. Even something as simple as a Stirling engine with forced circulation of the fluid works as a heat pump.

If you are referring to transcritical CO2 that is absolutely right. However you can't just use any pressure change in any gas, it would work but it would not be economically viable due to that inefficiency.

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

#75

Post by Freestyler_3 »

LatteLazy wrote: post #42

Everyone is looking for an easy answer to climate change / energy costs / energy independence etc. But there isn't one. Fusion remains decades away, Fission is very expensive and unpopular, Most renewables are intermittent etc. Heat pumps are one more tech with very limited potential (range of temperatures, efficiency over that range, power output limits, need for a heat source, size, cost etc).

I don't follow how heat pumps have limited potential. They have big potential.

Its not a one size fits all solution, that's all.

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

#76

Post by nemo44x »

TeMPOraL wrote: post #45
jdmichal wrote: post #37

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.

HVAC can do that and it’s not too expensive. You do need to run water to your unit though and there’s quite a bit of maintenance as humidifiers create mold, etc.

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

#77

Post by elil17 »

nickpeterson wrote: post #4

Why 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…

You'd need one of three solutions to make this work:

1) Long refrigerant pipes. This is unacceptable because it increases the amount of refrigerant in the systems (refereed to as the charge of the refrigerant). Refrigerants are powerful greenhouse gases so it is important to design low charge systems.

2) Another process fluid (e.g. water or glycol). This adds expense (more pumps and heat exchangers). You'd increase the cost of all these systems by a lot.

Also, both 1 and 2 involve running a new set of single use pipes around your house.

3) Make a "single appliance" household. A design like this has been tried - single AC/heat pump hooked to fridge, freezer, oven, dishwasher, washer/dryer, and water heater. The problem is that you really have do design the house around this and it is quite limiting from an architectural perspective.

Combined AC/heat pump and water heater is a thing though.

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

#78

Post by Freestyler_3 »

ComputerGuru wrote: post #62
sampo wrote: post #21

Earlier quoted context omitted.

> -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.

for those places where the scop is low, you have to drill for heat. If that's not possible then maybe a system where you can burn wood to suck the heat out of that.

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

#79

Post by elil17 »

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.

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.

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

#80

Post by elil17 »

tonyarkles wrote: post #40
ghettoCoder wrote: post #16

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.

And incandescent light bulbs!

No, because the light can escape through windows.
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