I’m planning to construct a home sometime in the near future in hot, arid part of the country. Obviously, keeping the home cool is a major concern and I’ve been considering all available options.
One of the recurrent ideas discussed online is using geothermal cooling. But I think I don’t have enough land to implement it. I have a related idea though.
Water supplied during set hours of the day by the municipality is fairly cool even during the summer months and it is a common practice around here to first let it collect in an underground tank and then pump it to the overhead tank as needed.
What if I create a closed loop system of circulating water with two car radiators: one in the underground tank, submerged in cool water and another in the living area of the home with a fan blowing behind it.
Do you think it’ll cause perceptible change in room temperature if there is, say, a temperature difference of 10 degrees Celsius between water and ambiance? I intend it to only reduce the load on the air conditioners and/or just delay the use of AC.
What kind of math/physics will be needed to assess if this is a feasibility? I tried looking hard but could not find anyone else discussing this idea, so I’m reaching out to you guys.
Thank you for your time.
As regards your point on the budget, i don’t think that two car radiators, some insulated tube and a small water pump will cost much, more so if I can run the pump off a small solar panel in the day time.
All said and done, if there is nothing in theory that advises me against trying this, i would like to give it a shot and document it so that someone else might learn from it.
Thanks again!
Well there is plenty of reason to not do it, but I’m assuming you’ve thought about what tampering with your water supply means (and that car radiators are not food safe, and could contain lead or other nasty metals). I think it goes without saying you’re also running the risk of leaks, a high water bill, and mornings without water if your system has issues.
I’d also like to cover my ass a little and do the typical engineer thing and remind you that an idealized number like this is never realized. You will have to account for losses due to inadvertent and incomplete heat transfer. But you may also get a higher reduction due to the ground heat exhange, which I am still too lazy to work out. ¯\_(ツ)_/¯
All of that said, I really hope you succeed at getting cheaper cooling and have fun doing it. There are houses which use water piped through concrete flooring to regulate temperature, so you’re not very far in uncharted territory. Doing big projects like this are also a really good way to learn a lot very quickly.
I also still highly recommend getting a quote for a reputable geothermal cooling system. If nothing else but to brag about how much you saved by DIYing
I’ll definitely take your advice regarding getting a quote from the geothermal system guys, if there are any around me.
I’ll also try and learn the science/maths to see if you, or the other guy who has suggested that this might not be worth the effort, are right.
Engineers describe heat transfer with a “heat transfer coefficient”, and the rate of heat transfer is this coefficient multiplied by the temperature difference. So you can calculate what the heat transfer coefficient must be by measuring room air temperature initially, water temperature initially, and then running your system for a little while and measuring the room temperature again. The smaller room area you can cool the more accurate this will be. You will need to look up heat capacity and density of air (easy to find), and the temperature change of the air with the volume of the room and the temperature change will together give you an amount of heat you removed from the air to the water. Simple!
While I have a background in science, this is not the specialization i chose and so almost all of it is almost Spanish (won’t say Greek, since at least I’ve heard of the words) to me.
I thank you for summarising the science of it though. It gives me enough keywords to start learning.