HomePerformance Venting Capacity

Solar Attic Fan Venting Capacity and Sizing Chart
How Many Solar Attic Fans Do I Need?

Several factors can affect the amount of attic ventilation a home needs. Variables such as vaulted ceilings, amount of existing venting (soffit, ridge, gable), attic shape, pitch and obstructions must all be taken into account when calculating the amount of attic venting needed. Your Natural Light dealer will determine the correct size unit or units needed for your specific installation. The output chart below reflects the average venting capacity and cfm output for each solar panel size available.

Natural Light Solar Attic Fan Output Chart
Solar Panel Size Venting Capacity CFM Output
12 Watt Model up to 1,260 sf up to 893 cfms
24 Watt Model up to 2,100 sf up to 1,339 cfms
36 Watt Model up to 2,625 sf up to 1,628 cfms
60 Watt Model up to 3,255 sf up to 1,995 cfms

CFM refers to cubic feet of air moved per minute. The higher the cfm number, the greater the capacity to move air. 

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12 watt roof mounted solar attic fan installed on an steep roof of a cedar shingle home.

Solar Attic Fan Residential Unit Estimator

The charts below should be used as a general guideline for how many Solar Attic Fans are needed for residential installations based on square footage and roof pitch.
Download Solar Attic Fan Estimator Sheet pdf.

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Attic Size Attic Fans Needed
800 sf (1) 12 watt
1,260 sf (1) 12 watt
1,600 sf (2) 12 watt OR
(1) 24 watt
2,100 sf (2) 12 watt OR
(1) 24 watt
2,400 sf (3) 12 watt OR
(2) 24 watt OR
(1) 36 watt
3,000 sf (2) 24 watt OR
(1) 60 watt
Attic Size Attic Fans Needed
800 sf (1) 12 watt
1,260 sf (2) 12 watt OR
(1) 24 watt
1,600 sf (2) 12 watt OR
(1) 24 watt
2,100 sf (3) 12 watt OR
(2) 24 watt OR
(1) 36 watt
2,400 sf (2) 24 watt OR
(1) 36 watt
3,000 sf (2) 24 watt OR
(1) 60 watt
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Attic Size Attic Fans Needed
800 sf (2) 12 watt OR
(1) 24 watt
1,260 sf (2) 12 watt OR
(1) 24 watt
1,600 sf (3) 12 watt OR
(2) 24 watt OR
(1) 36 watt
2,100 sf (2) 24 watt OR
(1) 36 watt
2,400 sf (2) 36 watt OR
(1) 60 watt
3,000 sf (3) 24 watt OR
(2) 36 watt
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NATURAL LIGHT SOLAR ATTIC FANS

Natural Light Solar Attic Fans reduce heat build-up in your attic and can minimize the load on your HVAC system. Available for all roof types, solar attic fans install easily with no electrical wiring or structural changes and blend seamlessly into your roof line.

© 2018 Natural Light Energy System