Solar Hot Water Systems
Water heating accounts for up to 20% or more of an average household’s annual energy expenditures. A properly installed solar hot water system (solar thermal) can reduce your hot water cost by 50% to 90%. Call us today for a free no obligation assessment.
The amount of hot water a solar water heater produces depends on the type and size of the system, the amount of sun available at the site, proper installation, and the tilt angle and orientation of the collectors.
Solar water heaters can be either active or passive, open-looped or closed looped.
- An active system uses an electric pump to circulate the heat-transfer fluid.
- A passive system has no pump.
Solar water heaters are further classified as open loop (“direct”) or closed loop (“indirect”).
- An open-loop system circulates household (potable) water through the collector.
- A closed-loop system uses a heat-transfer fluid (water or diluted antifreeze) to collect heat and a heat exchanger to transfer the heat to household water.
A typical active, closed loop solar hot water system consists of a collector, a storage tank with an internal heat exchanger and a controller. The most common controller is the differential controller, which turns the pump on when the water in the collector is about 8-16° F warmer than the water in the tank, and it turns the pump off when the temperature difference approaches 3-6° F.
Below are the three main components.