Go Solar for Free Hot Water
(Page 3 of 6)
February/March 2007
By Bob Ramlow
In climates that never experience freezing conditions, or for systems that operate only in summer, such as those for summer homes and campgrounds, water in the solar collector and piping presents no such threat. The best type of solar water heater for these applications is an integral collector storage (ICS) system, often called a batch heater. ICS systems are simply water tanks exposed to the sun. Commercial ICS collectors have one or multiple tanks inside an insulated box with glass on one side. The glass side is set facing the sun, and the tanks are painted black or have a special coating that absorbs the sun’s energy. This system has no pumps or controls and is plumbed directly into a home’s water system. It is the simplest, least expensive solar water heater and is popular in all areas surrounding the equator. ICS systems heat domestic water directly. Other systems heat the water indirectly, using a heat-transfer fluid that is kept separate from the water supply, because most water supplies contain dissolved minerals that will clog the small passages in other kinds of solar collectors.
RELATED CONTENT
How Hot Is HOT? February/March 2004
The Other Chile Peppers
Where does the h...
Want to know how to build your own photovoltaic system, how to construct a solar water pump, or eve...
It’s not every day that you get a chance to tour a green home. Well, here’s your opportunity! Every...
A string of new solar manufacturing plants are scheduled to open within the next few years....
Your woodstove can heat more than your home. This hot water heating system uses extra heat to produ...
Solar Hot Water: Cool and Moderate Climates
In areas that experience freezing conditions, two kinds of solar water-heating systems are appropriate, closed-loop antifreeze systems and drainback systems.
Closed-loop antifreeze systems are the most popular and versatile type of system installed worldwide. They consist of one or more collectors, insulated piping, a circulating pump, an expansion tank, a hot-water storage tank, a heat exchanger, solar fluid (usually a solution of water and nontoxic propylene glycol antifreeze), a controller, and some valves and gauges. The piping loops from the collectors to the heat exchanger and back again. This closed loop is filled with the antifreeze solution, which stays inside the collectors and piping at all times. Whenever the sun shines on the collectors, the circulating pump comes on, and the solar fluid circulates within the closed loop. The fluid gets hot inside the collectors and travels through the piping to the heat exchanger. The heat exchanger transfers the heat from the fluid to the water inside the storage tank, which stores the heated water for your use. As the fluid heats, it expands, so the expansion tank is included to relieve pressure in the system. When the sun is not shining, the circulating pump simply turns off, and the fluid stops circulating.
The circulating pump in these systems can be powered by either AC or DC current. If AC-powered, the pump gets its energy from your home’s 120-volt electrical power system. In this case, a controller is necessary to turn the pump on and off at the appropriate times. The controller is connected to temperature sensors in the collectors and on the storage tank. Whenever it’s hotter in the collectors than it is in the storage tank, the controller turns on the pump. When it’s warmer in the storage tank than in the collectors, the controller turns the pump off.
Page:
<< Previous 1 |
2 | 3 |
4 |
5 |
6 |
Next >>
