This is a write up on a heater I designed a year or two ago. The design of this heater will maintain 500 gallons of water at 80 degrees F. The animals will have no contact with the heater because it is not inside the enclosure, but it will require a pump to keep the water moving through the heater assembly. The cost is around $15 minus the thermostat. The list of supplies is small and all can be purchased at your local hardware store. Because of differences in each enclosure however, some prior planning will be required to determine what size fittings will be needed.
1. Heating element.
2. One lead pipe reducer.
3. One threaded connecting pipe.
4. One length of pipe.
5. One lead pipe “T” junction.
6. Pipe sealant or plumbers solder.
7. Miscellaneous fittings for connecting to pump and enclosure.
8. Thermostat.
The first piece is the heating element. This is a replacement element from a household water heater. The important thing is to check what voltage source is used in your part of the world. For those in the U.S. a 120volt unit is probably best. This piece may be a special order as most are 210volt. Minus the thermostat this is the most expensive part of the heater costing about eleven dollars.
The second item is the reducer. This is what the element is attached too. It should be threaded on one end to enable the heating element to screw directly into it, and be threaded on the other end to have the connector attached.
The connector is a length of pipe that is threaded on both ends. It is used to connect the reducer to the “T” fitting.
The “T” is the middle section of the heater. It should have three openings, one on each end and a third in the middle. This is what will allow the water to be directed back into the enclosure after it is heated.
The last piece of the heater assembly is a single length of pipe, which should be threaded on both ends. It is connected to the “T” across from the element and should be long enough to cover the end of the element. The opposite end will be connected to the water input.
The thermostat is from a waterbed. Most can be set to keep water from 60 to 100 degrees. These can be found at any furniture store that carries waterbeds, or from numerous sources online. It will consist of a controller, two electrical cords, a heating pad and a temperature-sensing unit. They can be as low in cost as $25 or as much as $100 and come in a variety of different designs. The one used on this application was around $40 and did a fine job.
To assemble, place a small amount of sealant or plumbers solder around the threads of each threaded piece and the screw them together, first the reducer to connector, then the connector to the “T” and finally the length of pipe to the opposite end of the “T”. All pieces should be snug but hand tightened is fine. When the sealant has dried screw the heating element into the reducer. To complete the heater assembly, connect whatever fittings are required to attach the water input and output hoses.
To connect the thermostat to the heater, locate the electrical cord that is attached to the heating pad. Cut the heating pad off the cord about an inch from the pad. Inside this cord there are two wires. Cut the cord length-wise two inches to expose these two wires, then strip about one inch off of each wire’s insulation. There will now be two pieces of exposed wire about an inch long protruding from the end of the electrical cord. Take the heater assembly and locate the two screws on the end of the heating element. Connect one of the two exposed wires to the positive screw, and the other wire to the negative screw. Plug the opposite end of this cord into the thermostat control. Next, locate the temperature-sending unit. This will look like a copper hose about four feet long. Place it firmly against the heater assembly and secure it with electrical tape. This will complete the entire water heater.
There are a few admin notes that go along with this design. Water must be continuously moving through the heater assembly, so make sure the heater is unplugged before the pump, otherwise the element will burn up and need to be replaced. Also, as with anything, make sure to keep the electrical connections dry as electricity and water do not mix. Hope this will work for some of you getting ready to build your next enclosures. Happy Holidays!