Monday, November 8, 2010

Heating and cooling options for the Modern Camper!

I was building an online listing for a used motor home and in the list of options available I saw "swamp cooler". After asking everyone I know and consulting GOOGLE, I realized that there are a lot of options out there that most people wouldn't know about.

A swamp cooler is a system that you won't see much of anymore. Water sprayed over another water line or even an air duct, evaporates into the surrounding air. Either a warmer ambient air or an artificially heated air. Through the process of evaporation, whatever the water is in contact with when it evaporates actually cools 10-15 degrees. Similar to our own bodies when we sweat. Though environmentally friendly, the side effects are not the most desirable. Algae, mold, mildew and odors have pretty much done away with the system.

Another system that is slowly becoming more popular is a heat pump system. Heat pumps have the ability to move heat energy from one environment to another, and in either direction. This allows the heat pump to both bring heat into an occupied space, and take it out. In the cooling mode a heat pump works the same as an ordinary air conditioner (A/C). A heat pump uses an intermediate fluid called a refrigerant which absorbs heat as it vaporizes and releases the heat when it condenses. It uses an evaporator to absorb heat from inside an occupied space and rejects this heat to the outside through the condenser. The refrigerant flows outside of the space to be conditioned, where the condenser and compressor are located, while the evaporator is inside. The key component that makes a heat pump different from an A/C is the reversing valve. The reversing valve allows for the flow direction of the refrigerant to be changed. This allows the heat to be pumped in either direction.
In heating mode the outdoor coil becomes the evaporator, while the indoor becomes the condenser which absorbs the heat from the refrigerant and dissipates to the air flowing through it. The air outside even at 0 °C has heat energy in it. With the refrigerant flowing in the opposite direction the evaporator (outdoor coil) is absorbing the heat from the air and moving it inside. Once it picks up heat it is compressed and then sent to the condenser (indoor coil). The indoor coil then rejects the heat into the air handler, which moves the heated air through out the RV.
In cooling mode the outdoor coil is now the condenser. This makes the indoor coil now the evaporator. The indoor coil is now the evaporator in the sense that it is going to be used to absorb the heat from inside the enclosed space. The evaporator absorbs the heat from the inside, and takes it to the condenser where it is rejected into the outside air. This system is nice but not recommended in temperatures below 15 degrees. In my opinion, anything below 40 degrees deserves a conventional gas furnace. But that's just me. If yo have anything to add, please do so. I'd like to hear other campers opinions from around the country in different climates.