Evacuated tube, Debec

System

Sun: 4 banks of 20 Evacuated Tubes

Efficiency: R40 in ceilings, R20 in 2x6 stud walls.

Cost: $7000 for all materials O&M no costs since install.

Date of Installation: Summer 2007

Type/kind: Residential (Family of 4)

Installer: Self Install

Supplier: Sunrain (http://en.sunrain.com/) tubes supplied by Huong Long

Experience: Fairly straightforward install, happy with job done.

Results: Last winter spend only $200 in heating costs

Description of Case Study: This solar thermal system provides both hot water and in-floor heating to this house and garage for a family of four, and has a 40 gallon tank for thermal storage along with a 15kW electric heater as a back up. In the summer, two of the four banks of evacuated tubes are covered, and the heat is used for hot water.

During the winter time all four banks of evacuated tubes are used, producing the main source of heat for the garage and house, which are both one story and have an area of roughly 2000 square feet. The heating comes from passing glycol through tubes set in the concrete floor of the buildings. Each section of the house has its own separate heating control, allowing for adjusted heating. This combined with the energy efficient envelope of the house allow the solar thermal system to meet a majority of the heating needs for the buildings, with the electric heater being a backup that is rarely used. At times, too much heat is produced by the solar thermal system.