How to: Solar Water Heating Plans

Batch Heaters

• 1

  Determine the needs of your household for hot water usage. The usage will depend greatly on the number of people in your home and how you handle your household chores. Water for cooking can be heated, but showers and laundry need a preheated supply of hot water as does washing dishes. Decide if one tank is enough to supply hot water for a given length of time, as it takes longer to provide hot water via solar power than a gas-powered water heater. You can also consider using the solar heater and having a secondary back-up conventional water heater if necessary.

• 2

  Clean out the hot water tank or tanks, and paint the tank black on the outside to absorb more of the sun's heat.

• 3

  Construct a plywood box that is large enough to house the tanks and has a large Plexiglass lid that allows in sunlight while trapping the heat inside the box. The box and tanks should be located where the sun is exposed the longest to collect the most heat. The tanks should not fit tightly together inside the box, and the lid should be large enough to allow in maximum sun, about 1 square foot of Plexiglass for every 2 gallons of hot water you housed in the tanks.

• 4

  Install the tanks inside the box and connect it to the plumbing fittings. Place the lid on the box and seal the edges with silicone caulk. Hook the plumbing lines from the box into your home system at the point where your hot water tank is. For this portion the hot water tank can remain in place inside the home if it still exists, however it can be shut off. The hot water from the outside solar tanks can be collected inside in this tank, and can provide more hot water faster.

Tube Heating Systems

• 5

  Coil tubing or make parallel lengths of tube that curve around at the top and bottom like a grid to make a tube heating system. The tubing should be black plumbing-grade flexible plastic tubing. The tubing can be coiled into a large flat circle or made in the grid pattern, but the important factor is the tubing needs to lay flat.

• 6

  Construct a box or in warmer climates attach the tubing directly to the roof with galvanized hose anchors. If the tubing is being built inside a box, the box needs to be painted black inside and covered with a Plexiglass or glass lid.

• 7

  Attach plumbing fittings to the box or tubing and route it to the water system in your home. Cold water should feed into the tubing through a plumbing connection that has a shut off valve. The exit tube can feed into the home and the hot water tank. This is a gravity-fed system in which the tank pulls in water from the tubes, then draws in new cold water for heating.