Collector Sizing Steps

The most common application of a Solar Collector is domestic water heating,  because hot water is needed year-round. When designing a solar water heating system, decide first how much hot water will be used per average day. Other information you will need is:
Insolation, Hours of Sunshine per Year
Deviation from North/South line
Difference between local Latitude and Roof Angle
International units of measurement are used for scientific communities.

Step 1

Size the system based on the number of people using hot water.

Step 2
Using local data, find hot water consumption per day, per person.
ASHRAE recommends 20 gallons per day, per person.
Step 3
Select the Solar Water Heater tank size.
Step 4
Find Solar Insolation and hours of Sunshine per year.
Step 5
Select the Solar Collector Installation location.
Step 6
Calculate deviation from true North/South line.
Step 7
Find local Latitude
Step 8
Find Roof Angle or installation Tilt Angle.
Step 9
Calculate the difference between local Latitude and Roof Angle.
Step 10
Estimate VM Tubes required.
Step 11
Contact your local dealer for Delivery and Pricing information

In the following four pages we are going to size a solar water heating system for a family of five. They have a hot water requirement of 50 liters per day, per person, with a local Annual Insolation of 1400 hours. Orientation of the roof is 30° West of South. The local Latitude is 45° and the roof angle 35° (inclination difference 10°). If your property is located in the US, go directly to US Insolation Charts.


NOTE: The information presented in this page is for guidance only - no part of this may be used for any agreement, whether express or implied, or to form any contract. THERMO TECHNOLOGIES reserves the right to change specifications and prices without prior notice.
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