Richard Good of Solar Services Inc. discusses the technical benefits of using a Flat Plate vs. Evacuated Tubes in your solar hot water installations.

1. Flat Plate Collectors VS.
Evacuated Tubes
Presented By: Richard Good

2. AP-30

3. AE-40

4. Performance in (Btu’s Per ft^2)
Btu's Per Panel Per Day Gross Area
Category Clear Day Mildly Cloudy AE-40 39.78 ft^2
AE-40 AP-30 AE-40 AP-30 AP-30 44.76 ft^2
A) (-9F) 52 46.1 39 34.8
B) (9F) 47 44 35 32.7
C) (36F) 40 40.6 27 29.3
D) (90F) 24 34.2 13 23
E) (144F) 9 27.1 1 16.8
Btu's Per ft^2
Category Clear Day Mildly Cloudy
AE-40 AP-30 AE-40 AP-30
A) (-9F) 1307 1030 980 777
B) (9F) 1181 983 880 731
C) (36F) 1006 907 679 655
D) (90F) 603 764 327 514
E) (144F) 226 605 25 375

5. Efficiency Based On Temperature
1
0.9
0.8
0.7
Collector Efficiency
0.6
Unglazed Pool Collectors
0.5 Selective Flat-Plate
0.4 Evacuated Tubes
0.3
0.2
0.1 1000 W/m^2 Irradiance
0
0 50 100 150 200 250 300
Collector Inlet Temperature Above Ambient (F)

6. Ice and Snow Issues