Depending on your body thermostat and the climate at your off grid home, keeping cool can be a challenge to your power system. Traditional AC units draw enormous power for their compressors. Earth or underground homes are nice, but not for everyone. Evaporative coolers and their variations have broad appeal for our off grid cooling needs. We’ll finish up with a free, primitive evaporative cooler.
The weather around these parts has been cooler and wetter than past years, so its not too hot yet. Personally, I don’t like anything much above 75F and 85F is unbearable. With the weather switch here in the mountains, we could wake up any day to the never ending 80s at any time. Reviewing ways to keep cool is just good planning.
Real AC, not really
Traditional air conditioning consumes quite a bit of power and works well if you have so much power available that you don’t need a power budget for planning. Unfortunately, most off grid moves are done on a budget, and most often that budget is of the shoestring variety. For example:
- A Frigidaire FRA054XT7 is a small
46 pound window AC nit
- Cools a 12×12 foot room
- 5,000 BTU unit will take 450 W.
- Assume it runs 12 hours/day
This example situation adds up to 5400 Watt Hours, or 5.4KWh. Its moderate for a grid home that uses 20-30KWh per day, but would require a very large solar array to power it! (or substantial cost in fuel for the genverter system.)
- If you wanted to run this off battery power for one day, you would require a bank of 6 Trojan L-16s in a 12V system, just for this daily purpose!
Bottom line is that traditional compressor based AC will only work in situations where there is a very large $$$ budget for the off grid power design.
Cooling by Home Design
Quite honestly, I’m not much of an architect, but there are several factors that will enhance the natural cooling in your home. Any home that has a cellar, or is built partially into the ground will benefit from the natural earth temperature. That is, it keeps things cool in summer, and above freezing in the winter. Having a cozy in ground retreat from the heat is very appealing to those in the desert areas.
Here are a few tips that will help you make the best of what you have cooling wise on those hot days
- Leave windows open all night. This will promote some ventilation and cool you home somewhat.
- Close windows in early morning and draw the shades closed on windows facing the sun. You want hold that little bit of cool air in! Keep moving as necessary to block the sun with your curtains or shades.
- When inside temperature equals outside temperature, open all the windows! Its time to hope for and enjoy any breeze and ventilation in the house.
Late afternoons when you want more ventilation, consider well placed low power fans to keep the air moving.
Evaporative coolers are the fancy name for what we commonly call “swamp coolers”. The whole idea is to inject some moist or humid air into a space with hot dry air. As the moist air dries out, it drops in temperature, cooling that space. There are many innovative designs for making your own unit with a fan and furnace filter, but we chose a small commercial unit from Home Depot a few years ago for about $150.
[I made the mistake of ordering it from Home Depot on-line, when a year earlier, I read news about their poor security in a tech newspaper. My card was compromised that day, with two subscriptions to some "relationship" site and a subscription to the Huston Chronicle. Just my experience, for what it is worth.]
Back on topic. Its a Ritetemp CoolAir 5051B cooler. This unit has 2 – 4 gallon tanks that slide onto the sides of what looks like a normal fan. It has a small pump that circulates water from the bottom tank through a filter in front of the fan. It senses when you’re out of water and shuts down the pump. Works nicely. Its amazing how much water it will go through on a hot day, so the large water tanks minimize your water filling trips.
Here’s a swamp cooler jewel to tuck away. My retired friend has used a swamp cooler to cool his home for the last 25 years or more. He said its always important to locate the unit on the sunniest hottest side of the building to make it work best. Sure is nice to visit his home on hot days and go from 95F outside to a comfortable 75F!
Free Primitive evaporative cooler
The good Lord has given each one of us a free evaporative cooler to help maintain comfortable temperatures. The natural system uses sweat to evaporate off the skin and body hair to drop your skin temperature. Unfortunately this system can be uncomfortable and smell at times. The best way to enhance the qualities of this system is to, “jump in the lake”! Yes thats why we all enjoy the water on hot days. We continually dip ourselves in the water and dry off (cool off) and then repeat for memorable and enjoyable times of relaxing!
I’ll bet you have some ideas or experience with swamp coolers? What are your best ways of keeping cool without consuming tons of electricity? Comment below now. What cooling improvement suggestions do you have?