Every once in a while I stumble on an idea that blows me away in its simplicity and design. Yesterday on Facebook I posted about a pint sized air conditioner that seems to be small enough to be practical for an on grid tiny house (or one that is producing adequate solar power for 110).
But this morning I started googling and I came across a very interesting post. It seems that we silly wasteful humans have gotten yet another thing wrong.
Why don’t we have single units that take care of our heating, cooling, refrigeration and hot water heating? SAY WHAT?
Did you know that we could be heating our water while we cool? And I suppose we could also be cooling our food while we heat? Even though this will be a no brainer for you science and electronics folks, I had no idea, and I think I am not alone. But the question is… why have you science and electronics folks NOT fixed it so that we have systems that save power and money? We need that!
This morning I learned that during air conditioning, the heat and the cold are simply exchanged. That is in essence all that happens inside these machines. More specifically, in a window air conditioner, the air is put through the machine and the heat both that of the machine and the air are sent to coils in the back and there is a fan that blows against the coils and this sends that air out the window. But the coils themselves are enclosed… so there is no need for this to happen. The coils can just as easily be sent to an adjacent water heater and or a hot tub. (see below video)
The same principal, I think would work for cooling, in the winter the air could, I am sure be exchanged so that the air becomes warm and the cooling is sent to a refrigerator. It would only be during moderate times or excessive cold or heat that one would need to use power beyond that of running the machine and I would hazard to guess that you only need power to cover the loss (the rules of hydrodynamics) and to run the machine.
How to reuse your refrigerators heat
A system like this would be ideal for a tiny house. Three units all stacked on top of one another like a little birthday cake to take care of our water, heating and cooling needs.
After thinking about this – I learned that I am not the only one who has wondered about this… Someone else with this Q & A… BUT none of these folks were thinking about it in terms of use for tiny or right sized homes. We have much smaller needs.
Anyone with thoughts on this? Could it work?
Tiny House Ontario 
Another view is that we don’t NEED air conditioning; a well designed and situated house has good air flow, shade, and window coverings to provide cooling.
Wouldn’t a small on-demand hot water heater be efficient?
Living tiny also might mean no need for a refrigerator (Dee Williams uses a cooler) by eating simpler meals.
Heating could be a tiny propane stove, I suppose (burning wood pollutes the air and destroys trees); it depends on the climate but a tiny, well insulated house shouldn’t need that much heat.
So many ways to look at tiny house issues and no perfect solutions!
Hi Hannah,
Perhaps in your climate, or in your able bodied world YOU don’t need air conditioning. But there are some people who do NEED air conditioning. I am pretty grateful for being healthy enough that I don’t need it at this time, and I hope that you will always be in a situation that you also don’t need it, but this is not to say that some don’t.
More to the point, you are not correct in your assumption about home efficiency. I am not sure where you live – but Tiny House Ontario is near Kingston Ontario, which is the most humid area of Canada. During the hottest part of the summer we carry ~90% humidity. When it is humid like this one cannot breathe well, even if you are optimally healthy. It is oppressive heat that you cannot escape. If you follow this blog, you will know that my house is completely enveloped by trees and well under the canopy. You will also know that my house is R 50 and R28, and my windows are double glazed, high end with RV blockers. You will also know that I have blinds on my sun facing windows, though I do not get any direct sun, just a smattering. Still my house is PIG HOT during the summer heat waves. Frankly, air conditioning would make it possible to breathe during these times. I would LOVE to have it! I would also have to have it so that it was doable by using my own solar panels and batteries. If this is an off grid solution, I don’t see why anyone would question the NEED. Why have you?
As for Dee Williams (who I love and respect), you are right. She using a cooler, so am I. However a cooler is NOT as wonderful as you think, fact is, I hardly ever use it. I am having guests who will need a cold drink or my dogs are here with me (so I can keep their food) this is the only time I buy ice. In order to have ice, I have to drive to the store in my car because it is 2 k away. Ice delivery and making is not really a solution… it is part of the problem. Unlike Dee, I also make my own solar energy to run my house and I also do not have the luxury of going next door to use the toilet and the shower. Don’t get me wrong… if I had a house next door where I had access to use these conveniences I certainly would use them. I would LOVE to have clean accessible running water and a nice tidy flush toilet at THO – with a reed system to take care of the waste and turn it magically into compost. I am just not quite there yet… Unfortunately money does not grow on the trees of an artist. I am doing what I can.
What I wonder, is if one can trade the cooling of the air, for water heat, a refrigerator for a furnace – why not? Wouldn’t you want to have one single plug used… and enjoy the comfort of four resources, instead of using four power using machines with each giving only a single resource – moreover, if you can have these things from power that your own solar panels are making, why would you object?
Living tiny is NOT about doing without and being uncomfortable. It is about using less resources. I would like to ask you – have you unplugged your refrigerator? Turned off your heat? Turned off your air conditioner? Unhooked your hot water heater (or turned it into an on demand)? Or are you an armchair environmentalist?
I think that we all need to do our parts to think this through – and not just throw stones at others who are not able to pay for perfect solutions.
I have been as you may or may not know living a reduced, anti consumer life for all of my 50 years. I did not (even) have a vehicle until I was 46 years old, but with age and illness I found that this was no longer practical for me. I would have loved to wait it out until technology and finances allowed me to have a fully electrically charged car which I could make the power for myself, but health did not give me this luxury.
Anyway… that is perhaps not the perfect solution that you expect of me, but I am doing what I can.
Laura – Tiny House Ontario
Hannah, don’t forget that Laura’s THO is in the middle of a forest. There should be enough deadfall for her to burn without cutting down any trees. That is good woodlot management.
Yes, you are right. There are more than ample branches for four tiny houses here to use for heating. There is no need to cut a living tree; however, I am not happy with my wood stove. I will be changing it.
❤ Laura
Yes, it could be made to work, economically and effectively, even on a small scale.
What is needed is a small-sized “heat pump,” (a Stirling engine), that would be used to pump its warm output into a water heater and its cool output into a refrigeration unit. The technology is 200 years old; but, Stirling engines weren’t able to compete economically with cheap coal and cheap oil. Now, for those who prefer something besides coal and oil, a Stirling engine built for use in a single dwelling, (not for industrial purposes), would be a marvelous solution. A Stirling engine could produce cold temperatures well below the needs of most freezers, and, at the same time, provide heat for the hot water tank. The main problem is that most every manufacturer today builds appliances to operate independently from its own electrical power source, (a power plug for each appliance). By adding the insulated tubing for a working gas or fluid, the only need for electrical power would be the controlling mechanism, (for the thermostat), and, of course, the light bulb inside the refrigerator.
In a Canadian climate, (where air conditioning is really only needed a few months in the year), an air conditioner could be added to such a system, at a minimal cost. The trouble is that, if one is using an electrical grid to power the air conditioner, you might as well buy it as a separate appliance for a small dwelling. Most heat pump manufacturers profit from building larger units for larger homes and don’t really downsize their products for the small market, (without a large profit markup); and, those small air conditioners may not be as efficient as heat pumps, but are easy to plug in to the existing power grid.
A couple of years ago, I questioned if the hot air produced by solar heating panels might be utilized in the summers, (when their hot air isn’t needed), to generate cool air. The idea was to eliminate, (or substantially reduce), the need for electrical power, by replacing the heat pump’s power supply with what would otherwise be waste heat. The hot air from solar heating panels and the normally warm outside air could be used to operate a Stirling engine, (in reverse), that would mechanically power another Stirling engine, (acting as the heat pump), to heat the water in the hot water tank, provide freezing temperatures in the freezer and refrigerator, and cool the air inside of a dwelling. It wouldn’t be as efficient as an air conditioner running off of the power grid; but, then, it wouldn’t add any cost to the electricity bill, (and could operate in an off-grid situation).
https://en.wikipedia.org/wiki/Stirling_engine
It’s an interesting concept, certainly worthy of further investigation. One must remember that these refrigeration circuits are designed to function as air-to-air heat exchangers. On the heat discharge side, those coils are designed to reject heat into air that is in an expected band of temperature. I don’t know if the refrigeration circuit would function well trying to discharge heat into a tank of water that is already over 100 deg F. That would be an interesting study.