Thermoelectric Auto Air Conditioner / Heater
Ok, I have an old 78 Ford truck with no air and no heater. The heater motor and vents are gone. The only thing left is the heater core. So, I can go to a dealer and pay three times the amount that the truck is worth to have it installed, or pay $1,000 for a kit and do it myself, or just use a fan. I also have seen many videos on YouTube of guys filling up buckets of ice and pumping the cold liquid through copper pipes around a fan to get a cool breeze. As ingenious as that is, I doubt it will work well in a vehicle. Plus, filling the thing up every hour or so would be a real pain.
I even thought about pulling an entire system out of the junk yard and then figuring out how to fit everything, and then having to replace my radiator, charge it up, etc. That was going to cost $400+ and a LOT of work. So, I have come up with the following plan that I have begun building. It is a Thermoelectric Air Conditioning and Heater unit with a total cost of $111.00.
I am sharing this idea and will post progress in hopes that people will comment and provide constructive criticism on my design and help in any problems I run across. Here are some opening thoughts:
The problem with the designs I am seeing on the internet is that you have to continue to fill up / empty the reservoir with either cold water or ice. I have decided to have a liquid coolant cooled and/or heated in a cooler (see Price List with links to parts), then pumped through a heater core and then back to the reservoir.
I am placing the CPU fans in FRONT of the heater core to draw and pull air from it instead of pushing air through it. I have read a lot of ideas and opinions on whether it is better to push, pull or do both. I am going to rely on my high school physics class and base my decision on the principle that it takes less energy to pull than it does to push. Plus, having the fans in front will avoid the resistance from the core fins themselves in a pushing situation and a shroud will be constructed around the entire front of the core into the fan area to maximize the flow of air.
The cooler/heater will need to be on a timer to start cooling or heating before the truck is running, I will also want it to continue to run and keep the coolant cool while I am in the store, or away for a while so when I get back in, I don’t have to wait for the coolant to cool back down again. This is why I am adding an additional battery in parallel and wiring in a battery isolator to prevent my starting battery from draining during this operation and also allowing my alternator to charge both batteries when the truck is running.
I am adding a controller that will control the fan speed and also keep track of the temp outside the truck, inside the cab, and also the temp of the coolant itself.
PARTS / COSTS
ACC Car Battery $15.00 Junk Yard
Battery Isolator $20 (used)
Heater Core $0 - used existing
3 CPU Fans $0 - had laying around
Cooler/Heater $30 (used)
Reservoir $0 - Old Container
Supplies (wire, tubing, etc.) $9