Our ultimate goal is to make the Airstream Off-Grid not relying on gas, propane or electrical hookups to meet our needs. During the warmer summer months the Airstream can get pretty warm inside – especially when in full sun! (Aluminum is a VERY good conductor!) With the weather heating up we began to look at different cooling options. Is it feasible to cool our trailer with an electric AC powered by the sun? What other cooling options are there? Read on for the answers to these questions.
The Land Yacht was originally outfitted with a AC-powered roof-top air conditioner. It seemed to function well but it was large, heavy and in my opinion made the exterior look like dump. (Especially after gale-force winds across the Montana plains stole the plastic shroud.) Given these facts plus wanting an off-grid solution I decided to remove the roof top air conditioner.
I added a roof vent to the opening where the old AC was installed so if we decided to upgrade to a newer, slimmer, unit we could easily remove the vent and install the new one. Plus the vent adds some nice light and additional ventilation.
I originally thought we would forgo an air conditioner altogether…the northwest summers are mild (with only a few short weeks of mildly uncomfortable heat) and the time we would spend in hotter zones would only be during mild winters. I installed two Fantastic-Fans (one in the front and the other in the rear) which can really move some air. I thought this would suffice…
I quickly changed my mind as summer set in! Aluminum is a fairly good conductor of heat and when the Land Yacht is exposed to long periods of hot sun the interior is like an oven. Our dual set of fantastic-fans was no match for the sun radiating through the aluminum! Trying to have a toddler nap in an aluminum can in the sun is not a good idea.
With this shift of thinking I began looking into various cooling options…
I had seen on the Air-forums people tactfully installing window air conditioners. I liked this option given the Northwest summer climate…we could install / use the air conditioner in hot weather then remove it altogether when not needed.
My next question was, “Is there a good DC solar powered off-grid solution?”
While there appears to be decent DC powered air conditioner technology it is expensive and I haven’t found a suitable non-permanent window solution. Until I find a fitting and affordable solution I purchased a small 6500btu window unit and I am going to run some tests to see if it would be feasible to power the air conditioner through an inverter with our future solar array.
Update: After doing some math its not feasible to consistently cool the Airstream with our window unit. See the usage data below.
INSTALLING WINDOW AC
We purchased a fairly cheap 6500 btu air conditioner for about $150 from Costco. If I was a little more patient I could have purchased a AC off of craigslist for about $75-$100 but we were going on a road trip and the weather was going to be HOT.
I wanted our window air conditioner to be easy to install and easily stored when not in use. The brackets I made to hold the compressor are pretty basic…a piece of wood that that has notches router’d out to fit on the bottom of the window, a little support from the propane tanks via a threaded piece of steel plus a little foam and we are in business.
Can’t be more pleased with the setup! When we need the AC we simply throw it in the window, no bulky box on the roof and it does a good job cooling the trailer!
|Total Run Time||5:27 hrs||6:28 hrs||7:30 hrs||11:30 hrs|
The AC uses almost 5amps AC. Convert this to DC Amps and you get 45amps. This means the AC would draw 270ah to run 6hrs per day. To only run the AC for 6hrs per day you would need over 500 Watts of Solar Panels + 540ah of battery capacity. For our setup this isn’t feasible.
In the future when we have more of a permanent setup an electric AC may be feasible with a larger solar setup. Meanwhile here’s our plan to cool the Airstream Off-Grid.
SUMMER – COOLING the AIRSTREAM
When we purchased the Land Yacht it had a large Coleman AC unit on the roof that worked fairly well. But this unit was big, bulky and the plastic shroud that covers it blew off in HIGH Montana’s winds as we drove it across country. So the fact that the AC is big, ugly and to replace the AC shroud would not be cheap ($200+) we decided to remove it. Here is our plan to keep cool during the summers:
We installed 2 Fantastic fans (one at the front and one at the rear) in the trailer. These fans can be powered by our solar battery bank and can really move some air which will help us stay cool(er) and comfortable during the warmer months. (We plan to spend our summers in the NW which is very mild during the summers but the Aluminum can get pretty hot.) When off-grid we will likely be parked in the shade which can keep the inside temp 8-10 degrees less.
For those times we have access to grid power and want to keep cooler we have a hand-me-down window AC unit that we will mount in the front window. This will take a bit of creativity and fabricating but I have seen other Airstream owners use this same solution. If we end up using our AC enough we may eventually get a newer roof-top unit with a built in heat-pump.
Meanwhile do you have any off-grid cooling solutions/ideas for a house on wheels? Would love to hear your ideas!