In this article, I'm going to discuss ways of keeping your off-grid home cool in the summer. Keeping warm during frosty winters when you live off-grid isn't difficult, as long as you have an extra layer of clothing and a decent stockpile of wood. However, staying cool during summer days when the mercury is rising, and limits on how much power you can use is an entirely different challenge.
Here are a few low-cost ways to keep your off-grid home cool during summer.
The materials used in building your off-grid home can soak up the heat like a sponge and radiate it into your living areas when the sun is beating down hard. It's not uncommon for the interior to get a lot warmer than outside because of the reduced airflow inside. Windows can also be problematic, as they allow the sunlight to penetrate indoors to heat the interior directly.
Natural shading from trees is one of the best ways to ward off the heat from the sun's rays. Use landscaping strategies that will take advantage of natural shade to reduce sunlight reaching your home. Unfortunately, landscaping isn't the fastest way to cool down because trees take time to grow. If you're planning on living at your homestead for a few years, then the effort you put in now will pay off in the future.
Trees will work best if you locate them around the southwest, southeast, northwest, and northeast corners of your home. You will need to plant large trees some distance from the residence to give the roots room to spread. Avoid planting heavily foliaged trees directly in front of windows, because they are remarkably efficient at blocking a cool breeze.
Deciduous varieties are also a good idea if you live in colder climates. They will let the warming rays of the winter sun through while blocking it during summertime. Taller trees will also help keep the sun off the roof for an additional cooling effect.
While you wait for your trees to grow, you can create extra cooling around the home by placing vine-growing plants around the exterior. Use trellises to place them around 12 feet away from the walls, so the air has room to circulate. Climbing beans and peas are excellent for this strategy, and they provide extra food as a bonus.
Photosynthesis and transpiration lower the surrounding air's temperature, so any breezes blowing past your vines and through your windows will be significantly cooler.
This can be a great solution to consider if you are planning on building your off-grid home. Earth tube "technology" is about 2,000 years old and they were first used during the Roman Empire. Earth Tubes are exactly what their name describes, a large tube (or series of tubes) buried in the earth which when air is passed through, can be used to cool, and in some cases, heat the air.
Earth tubes are most effective in extreme climates that have high heat in the summertime or extreme lows in the wintertime. They first came back into popularity in the late 1970s, but due to faulty installation techniques, many failed because condensation would build inside the tubes causing mold and bacteria to grow.
This created unsafe air to enter the home. Now in 2020, many people are having renewed success with Earth Tubes due to improved technology and lower cost of materials than was previously available. If done right, incorporating Earth Tubes into the design of your off-grid home can greatly reduce your home's heating and cooling costs.
Just remember to design and build your system the right way the first time and you shouldn't have any issues. It's those installations where people cut corners where they end up wasting time and money on their Earth Tube system.
Even warm air that is moving over your body will have a cooling effect because of sweat evaporation. At least, it will have, as long as the air is equal to or lower than average body temperature.
Windows and doors located on opposite sides of the room from each other allow you to take advantage of cross ventilation with strategically placed pedestal fans. Place a fan at one end and set it up to blow into the room. Another fan placed at the opposite door or window will blow air outside. Doing this will keep cold air moving through the room and expel any warm air that has built up.
If you're lucky enough to have a two-story home, you can take advantage of hot air rising by allowing it to escape through the upstairs windows. Ceiling fans set to an upward draft will enhance this effect. You can also combine this cross ventilation technique with an earth tube system to expel warm air through your roof and pull in fresh, cool air from beneath your flooring.
Ceiling fans and pedestal fans are a lot more energy efficient than air-conditioners. A swamp, or evaporative cooler, combines the power efficiency of fans with an evaporative cooling effect. Place one at an open window or door to blow cooler air into the room. When you keep the interior pads of these machines moist, evaporation reduces the temperature of the air flowing through to the room.
Solar power can produce much of the electricity a homesteader needs but air-conditioning often has power requirements beyond the capacity of all but the biggest, most expensive systems. When planning your off-grid home, you will want to definitely include the electricity you'll need for your cooling needs.
Most homesteaders will be able to use a modest size a/c unit to cool a small area, but the nature of solar means a/c units can only be powered during peak sun, and not during the evening. Even the smallest a/c unit will quickly drain a battery bank.
The earth itself is an incredibly efficient absorber of thermal energy. If at all possible, build part of your structure underground. Many homesteaders will use underground basements for storage, but they can also create a comfortable environment as a bedroom or a den. A basement will typically stay 10-15⁰ F cooler than other areas of the house.
Cooking inside can raise the indoor temperature of a small abode by a few degrees. An outdoor kitchen will keep the heat outside, where it will quickly dissipate into the atmosphere.
You may still become uncomfortably warm when cooking outside, so you might want to consider a slight change of diet during the summer months. Try eating more salads and cold foods that don't require heating or cooking.
If you are trying to increase the energy efficiency of your existing off-grid home or you're planning on building a new off-grid home, I recommend considering the application of several methods. When combined together, they'll help you keep your overall energy needs low when it comes to cooling your home.