Solar Consultants: Drainback Type

Solar fluid is water with an anti-corrosive additive. The fluid drains back from the collectors when the pump is not operating.
Protected from overheating in summer as well as freeze damage in winter, the system can be sized for space heating (more collectors and larger heat exchanger) in addition to water heating.
Larger pump is needed for solar loop, so drainbacks are slightly louder than pressurized systems.
Low maintenance (fluid level and buffer content should be checked at least every two years).


Twelve gallon drainback tank, pump, flow gauge; differential temperature control on wall.	Array of collectors for residential drainback system. Both systems pictured here supply heat for domestic water and radiant floors.

About SC

Last modified: 14 December 2004 7:23 pm

NC Renewable Energy Income Tax Credits, Federal Tax Credits, and Loans: For installation of renewable energy equipment. NC offers thirty-five percent tax credit for many renewable energy systems; commercial systems are also eligible for ten percent federal credit as well as accelerated depreciation. Various federal agencies offer loans for purchase of renewable energy equipment.