Sizing Hot Water Collectors & Tanks: We currently offer a variety of systems with well made flat plate collectors. The systems can be used to preheat water before going to your existing storage tank, or you can choose to use just one solar storage tank. Water storage tanks in solar water heating systems are typically larger and better insulated than your average home hot water tank, and generally they have four ports (instead of two) on the tank. You'll want to have at least 80 gallons of storage for a 1-3 person home or 120 gallon tank for a 4-6 person home. Sizing collectors is easy as well: allow about 20 square feet of collector area for each of the first two family members and 8 square feet for each additional family member if you live in the Sun Belt. If you live in the northern US, allow 12 to 14 additional square feet per person. Flat plate collectors are about 3'x 7' up to 4' x 10' and can weigh between 100 and 150 pounds each.
Types of Solar Hot Water Systems: In addition to selecting an appropriate sized system, you'll also have several options to choose from. Here's where the vocabulary comes in: active/ passive; open/ closed; PV powered or AC powered; drainback, etc. For a detailed description of each type of system, please visit our article in the How To section: . We currently carry a selection of active systems. These systems use pumps to move the liquid between the collector and the storage tank. Passive systems, or thermosiphon systems, rely on gravity: the hot water will naturally rise to the top of the collector as it heats. Another main category of distinction is an open versus closed system. An open system, also referred to as "direct" circulates the potable water through the collector. A closed system (a.k.a. "indirect") circulates a mixture of water and glycol through the collector and then transfers the heat to the potable water through a heat exchanger. A drain-back system allows water from the collector to drain back into a small tank to prevent water from freezing in the collector.
Solar Hot Water System Manufacturers: Your system selection depends primarily on your location. For example, an open (direct) system is a simple system that works well only in areas that will NEVER see freezing temperatures. Most often, people choose a closed (direct) system. The propylene glycol mixture prevents fluid from freezing in the collectors and is suitable for all locations. A system with a drain back tank offers similar freeze protection. Alternatively, a drain back tank can protect the water from being overheated during periods of reduced usage. AET and Heliodyne offer comparable products; how should you choose between the two manufactures? Both companies produce quality products and stand behind their warranties. One important difference to consider is shipping costs. Heliodyne is located in California; AET is in Florida. Both the AET (Alternative Energy Technologies) and Heliodyne system kits come with the basic components of the system - however, you will still need to provide the pipe and plumbing odds and ends. The company Solar Roofs manufacturers just the solar collectors (tanks are sold separately). The Solar Roofs collectors offer the unique advantage of being much lighter than the other flat plate collectors.
No matter what manufacturer you prefer, you'll be taking a great step forward by installing a solar water heating system in your home or business. Solar water heating is also a great option for Solar Pool Heaters. Although the concept of heating water with the sun is simple, the installation of a complete solar water heating system can be a fairly complex. Consult a local professional if you need installation advice. If you plan on installing the system on your own, you will definitely want to read Bob Ramlow's book, Solar Water Heating, Comprehensive Guide For more info about solar water heating, visit our How To section or check out the information on the Department of Energy site or FSEC (Florida Solar Energy Center). Get started with Solar Water Heating today!