Homemade Solar Water Heater Plans

Installing a hot water heater can help to reduce the costs of water use.

One of the advantages of building a solar hot water heater is that you can immediately reduce energy costs associated with heating water. Depending on what type of design you implement, as well as the climate in your location and exposure to the sun, "your water heating bills should drop 50%--80%" (Energysavers.gov). However, it is still necessary to have a traditional gas or electric hot water system for cold, cloudy days or periods of higher water use.

Things You'll Need

• Water heater tank (not currently in use)
• Plywood box big enough to hold the tank
• 2 sheets of clear plastic or glass
• Plumbing fittings
• 6 bypass valves
• Insulation
• Black paint
• Paint brush
• Power drill with wood bit big enough for pipe fittings
• Silicone caulk with caulk gun

Instructions

1. Designate the place where your solar hot water heater will be located. Ideally, you will want to put it next to your house where it will face a southerly direction, which will guarantee the greatest possible access to sunlight. Another consideration for selecting your location is to place the solar hot water heater close to where your traditional water heater is located inside your home, thus eliminating heat loss due to warm water running through a network of pipes. The cold water inlet also needs to be positioned at the bottom of the tank.

2. Scrub the spare hot water tank, which will become your home made solar hot water heater, with a wire brush and paint it black. Also make sure that you have all of the necessary fittings to run the water from the solar tank to the rest of the water heating system.

3. Construct the a plywood box which will house the solar hot water heater. The box should be sized so that the solar hot water heater will have a ratio of 1 square foot of glass on its front side for every 2 to 2.5 gallons of water stored in the tank. The 1:2 ratio is the best proportion of glass to gallons for the most efficient solar gain when heating your water. A 40 gallon water heater should be matched with a standard patio door replacement glass pane, which measures 34 inches by 76 inches.

4. Install the tank into the plywood box and insulate the plywood box with double-paned windows or multiple layer glass so that the trapped air will serve as an extra measure of insulation. Use silicone to caulk the plywood box in order to create a seal where the heat will be trapped inside and unwanted moisture will be prevented from entering the box from the outside. Drill holes for pipes so that water can travel back and forth from the solar hot water heater.

5. Connect solar water heater to the traditional water heater located inside your house. Install two bypass valves leading from your current water heater's cold water supply to the solar hot water heater so that you can regulate where the cold water is flowing to (Energy Savers: Solar Water Heaters). Install piping that will carry the water heated by the solar unit. The piping should run from the hot water outlet on the solar hot water heater to the cold water inlet of your traditional heater.

References

• The Economics of a Solar Water Heater
• Solar Water Heaters
• Mother Earth News

Resources

• The Renewable Resource Data Center
• Solar Radiation Data Manual
• Epsea