I came across a gentlemen on another forum who built (and well documented) a mini RV out of a cargo trailer and he experimented with taking a transmission cooler + CPU fans and plumbed them in a small loop between his hot water heater intake/outtake to allow the hot water to heat his small trailer. My wife and I are going to start full time RVing (in Colorado, yeah I know crazy) and instead of sticking an electric heater in our wet bay / front storage compartment I've considered trying the above idea as it seems like it would be safer (with the furnace as backup if temps really drop since it heats the bay).
Has anyone tried this? In a roughly 10x12 cargo trailer the guy claimed when his hot water heater was set to medium temp it kept his whole trailer around 74 degrees all night. I'm thinking if I can add a thermo controller and perhaps a fan controller (or just arduino with relays) to manage the circulating pump and fan speed I should be able to use it to keep the bay above 50 for very little cost. The water heater is both gas and electric and normally I only use electric but it's one of those "claimed 20 gallon" ones with the quick recovery so I'm thinking as long as the thermo controller doesn't keep the pump circulating constantly it should be somewhat efficient, though not fast heating.
Has anyone tried this? In a roughly 10x12 cargo trailer the guy claimed when his hot water heater was set to medium temp it kept his whole trailer around 74 degrees all night. I'm thinking if I can add a thermo controller and perhaps a fan controller (or just arduino with relays) to manage the circulating pump and fan speed I should be able to use it to keep the bay above 50 for very little cost. The water heater is both gas and electric and normally I only use electric but it's one of those "claimed 20 gallon" ones with the quick recovery so I'm thinking as long as the thermo controller doesn't keep the pump circulating constantly it should be somewhat efficient, though not fast heating.