﻿Solar thermal system beats stagnation problems
A.O. Smith solar thermal systems for producing domestic hot water have a patented system to overcome the problem of stagnation in the panels. Mounted directly below the solar collector, the drain-back system avoids stagnation, when the heat-transfer fluid can overheat and start to break down. There is also no need to start the pump to get rid of excess heat when the demand for hot water is low, and no need to build in an oversized storage system to cope with excess heat.
The heat-transfer fluid in the panels is not pressurised. When there is no demand for heat, the pump is switched off and all the heat-transfer fluid drains back into the reservoir beneath the panels.
A complete system comprises solar panels with an SGE or SGS condensing gas-fired water heater and an intelligent control system. All the system elements communicate directly, resulting in up to 40% solar contribution. If the solar input is low, the pump speed can be modulated down to 15% of nominal speed, maximising the solar energy available.
The panels and water heater are supplied as an integrated system, with commissioning carried out by fully trained technical staff.