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Revised Solar Water Heating Deemed Savings Estimates

June 4, 2003

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Reason for Revisions

• Current “Deemed” Values based on system with 40 sq.ft. collector area

• Initially proposed deemed savings values to cover three “generic” sizes used in Oregon Tax Credits and “Brightway” specifications– 37.3 sq.ft.– 60.0 sq.ft.– 74.6 sq.ft.

• RTF Recommended Adding More Size Ranges

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Originally Proposed Deemed Savings for Solar DHW Systems

Solar Zone Collector Area = 37.3 sq. ft. (kWh/yr)

Collector Area = 60.0 sq. ft. (kWh/yr)

Collector Area = 74.6 sq. ft. (kWh/yr)

Zone 1 1,800 2,200 2,400

Zone 2 1,900 2,300 2,500

Zone 3 2,100 2,600 2,700

Zone 4 2,400 3,000 3,200

Zone 5 2,500 3,200 3,400

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Revised Deemed Savings for Solar DHW Systems

Solar Zone

Collector Area =

20–30 sq.ft. (kWh/yr)

Collector Area =

31– 40 sq.ft. (kWh/yr)

Collector Area =

41-50 sq. ft. (kWh/yr)

Collector Area =

51-60 sq. ft. (kWh/yr)

Collector Area =

61-70 sq. ft. (kWh/yr)

Collector Area =

71 - 80 sq. ft. (kWh/yr)

Zone 1 1,400 1,700 1,900 2,100 2,300 2,700

Zone 2 1,500 1,800 2,100 2,300 2,400 2,500

Zone 3 1,700 2,000 2,300 2,500 2,700 2,700

Zone 4 1,800 2,300 2,700 2,900 3,100 3,200

Zone 5 1,900 2,400 2,800 3,100 3,300 3,400