Using Attic Heat to Cool House

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I had one of those refrigerators when I lived off the grid in the Bahamas. It wasn't working when I moved in, but I removed an obstruction in the gas line, and then it worked like gangbusters, freezing everything. I finally got it regulated where I wanted it.

I'm told that this type of refrigerator was invented by a guy named Albert Einstein.

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Go to the home page (thewiredshopper.com) and search for "propane refrigerator." You'll find it among the list of articles. (",)

regards,

Vulcan

The Propane refrigerator uses Ammonia for the cooling agent and requires a Live flame which is achieved by burning Propane gas. Propane gas when burning correctly reaches about 1982°Celcius, not quite in the normal attic temperature range of 20°C to 65°C.
The only gas with a boiling point in this temperature range is Propane (20°C) and Butane (50°C) Would you really want to start filling your attic with Propane gas contained in a system under pressure ??
As Propane is about 50% heavier than air, any leak would sink into your house, one electric arc, turning a light on or telephone wringing and boom !
The question would be the construction of the system required to not only produce the cooled air but how to circulate it in the house.
Personally, I would think it would be far simpler just to buy a convention A/C unit !!
Maybe run your cold water supply that goes to your water heater through the loft so the water doesn't need as much energy to get to temperature.
There are systems that use Solar to heat water in tubes on the roof but that is naturally limited to daytime and only when the sun shines, it the attic is also warm in the night.

I was thinking of refrigerants like Freon or similar gases, with different boiling points, not Propane.

I am trying to enhance, not replace a conventional a/c unit.

I have thought of using a radiator in the air return with cold well water circulating through it to reduce heat load, but have not done a cost analysis on this method.

I am considering the possibility of adding heat pipes to my system to increase efficiency.

Both an A/C and a refrigerator are heat pumps; they both move heat from a cooler space to a warmer space.

I'm thinking that a refrigerator moves a smaller amount of heat against a high temperature gradient, whereas an air conditioner (A/C) moves a larger amount of heat against a smaller temperature gradient.

An electrical analogy: a refrigerator is like a high-voltage battery that can only supply milliamps, but an A/C is a low-voltage battery that can supply amperes.

I have thought about using a swamp cooler in the attic to supplement the AC in the house. In fact it might be all you need. The extra humidity shouldn't be a problem, unless you have a water leak. But AC dehumidifies the house which is a great advantage.

In addition to central AC, I have a large fan in my garage with a screen door to the house in case there are mice. When the outside temperature is below 72F, running the fan with a open window in the bedroom is very effective. It also cools off the attic at the same time. If you just want to cool the attic then open a garage window and keep the door shut.

https://www.youtube.com/watch?v=cy1W-uWvR9Uhttps://www.youtube.com/watch?v=cy1W-uWvR9U

Not a perfect explanation but sufficient. I would not want pipes of ammonia and hydrogen running through my house.

That said, is this process possible with other gasses? I think that is where Highteck is going here.

https://www.google.com/search?q=how+does+a+propane+refrigerator+work+animation&client=ubuntu&sca_esv=3d188af4942300d6&channel=fs&udm=7&biw=1878&bih=934&sxsrf=AE3TifPHLD9RSansjd5syshVQK_2_ng_gA%3A1758596356111&ei=BA3SaN--Bpm-kPIP89Cq4Qc&oq=lp+refrigerator+how+it+works&gs_lp=EhZnd3Mtd2l6LW1vZGVsZXNzLXZpZGVvIhxscCByZWZyaWdlcmF0b3IgaG93IGl0IHdvcmtzKgIIADIKEAAYsAMY1gQYRzIKEAAYsAMY1gQYRzIKEAAYsAMY1gQYRzIKEAAYsAMY1gQYRzIKEAAYsAMY1gQYR0i_G1AAWABwAXgBkAEAmAEAoAEAqgEAuAEByAEAmAIBoAIJmAMAiAYBkAYFkgcBMaAHALIHALgHAMIHAzItMcgHBg&sclient=gws-wiz-modeless-video#fpstate=ive&vld=cid:0e76f2e2,vid:EYshi631z-Y,st:0

This is a very detailed technical explaination of the process.

That is what I am considering. I understand how the lp refrigerators work, and I am considering other gases less volatile.

Here is my understanding...

A gas refrigerator is a heat engine driven by the heat of the propane flame, which is absorbed at a high temperature and exhausted at a lower temperature (into the room). The refrigerant gas is just carried along for the ride and provides cooling for the inside of the refrigerator. In essence, you have a big heat engine driving a small heat pump.

For the A/C, if the attic is the heat source, where is this heat exhausted at a lower temperature in order to perform work, i.e., cooling the secondary gas?

Yeah but which ones? Water is OK. I could see Argon in place of Hydrogen. But the working gas? CO2 is out as it doesn't liquefy, instead it goes from Gas to Solid directly. It does dissolve in water.

That is at normal atmospheric pressure.

Under high pressures, a liquid phase is available.

Hence R744 is a refrigerant with a CO2 equivalent rating of 1. Because it is CO2.

Propane is commonly used now as a refrigerant: R290.

Exactly. The boiling point of any liquid depends on the pressure in the system, so a design that used different boiling points of 2 or more gases should work, and the pressure in the system could be modulated to provide a control method.

I do not have the means or methods to develop this idea, but I am sure there are engineers that do.

Instead of trying to use the Attic heat to cool your house, it would be far cheaper and safer to reduce your heating bills by using the attic heat to warm the cold water before it gets to your heating / hot water system.
You simply extend the incoming cold water from your mains supply which goes to your Water Heater by constructing a series of pipes in your loft, like a giant car radiator and the prewarmed water enters your water heater and does not need as much energy to reach your working temperature.
No Gas under pressure / pumps / etc. just pure water at normal mains pressure.
IMHO, it makes far more sense than what you are planning !

But those pipes will freeze in the winter causing big problems when they break.

Only when the temp. would fall below 0°C but bear in mind the average temp. of the incoming water would be roughly 10°C so the water would have to cool off to 0°C first, even if the air temp. in the attic was 0°C. and also that is assuming the the water would be stationery and it would naturally, depend on where Redneck lives. By the use of the name "Rednek" favours the southern USA where minus Temps. are not often encountered.

Cooling is more expensive than heating in my area, that is why I am experimenting with cooling first.

The normal heat pipes use partial vacuum to adjust the liquid/vapor transitions of the 2 gases.

Freon type gases do liquify under certain pressures and temps, some at very low almost room temps depending on pressure.

A combination of two gases with different phase changes temps/pressures could accomplish the same thing. I do not know what the gases are, but I am sure there are some.

Insofar as using well water to assist cooling, the transfer medium could be ethanol based in a closed loop system to prevent freezing, using the well as a large heat sink. Alternatively, a heat tape surrounding the insulated water line with a self regulating heat tape would prevent freezing.

If properly insulated it would require very little energy to keep the water from freezing.

In the winter, the well could function as a heat supplement by using the ground water temp of around 55F, just like ground source heat pump systems.

With the proper amount of flow and radiator deign it could provide all of the heat, cool requirements.

I am imagining a coil of copper tubing immersed in the well, which is 24 inch inside diameter concrete tile, surrounded by 6 inches of concrete which is surrounded by normal earth which is a wet gravel/clay/sand mix. with 17 feet of standing water column with a flow through of 10 gallons per minute.

The water, tile, and soil should absorb a lot of heat, but I do not know how much.

Just in the planning mode at present considering many possibilities.

All feedback is very much appreciated.

Heat pipes in A/C systems:

https://rhcchvac.com/what-are-hvac-heat-pipes/

https://www.heatpipe.com/engineering-manual/heat-pipe-principle-and-applications/

I have a two story house with a a solarium on the top floor. I have an air return on both floors. In the summer, I block off the solarium return and in the winter I block off the lower floor return.

This recycles the warm air from the solarium from the top to the bottom to help reduce heat load in winter, and reduces the cooling load in the summer.

A thermostatic controlled attic ventilator removes some of the heat from the solarium in the summer.

I am always looking for more ways to improve efficiency.