QuietCool AFR SLR-40 Solar Roof Fan
#7 in Roof mountFull review
For a medium attic on a roof that faces away from the sun, where the tilting panel earns its keep. On a south facing roof the 25 W model is better value.
QuietCool $439$439
The QuietCool AFR SLR-40 Solar Roof Fan is the better solar attic fan overall, rated 3.3 to 3.0. The QuietCool AFR SLR-40 Solar Roof Fan leads on panel and features. The QuietCool AFR SLR-25 Solar Roof Fan costs $160 less ($279 vs $439).
QuietCool AFR SLR-25 Solar Roof Fan
#9 in Roof mountFull review
For a small attic where a low cost hybrid fan with a long warranty matters more than airflow. Larger attics need the 40 W model or two fans.
Amazon $309 QuietCool $279$279
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the QuietCool AFR SLR-40 Solar Roof Fan for panel (40 W panel vs 25 W panel) and features (thermostat, AC backup, separate or tilting panel vs thermostat, AC backup).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every roof mount solar attic fan; a clear win is highlighted. How we rank explains each one.
| Factor weight | QuietCool AFR SLR-40 Solar Roof Fan | QuietCool AFR SLR-25 Solar Roof Fan |
|---|---|---|
| Overall rating | 3.3/5 | 3.0/5 |
| Value 25% | 22 $0.40 per CFM ($439, 1,085 CFM) | 39 $0.30 per CFM ($279, 927 CFM) |
| Airflow 15% | 26 1,085 CFM | 17 927 CFM |
| Panel 20% | 60 40 W panel | 30 25 W panel |
| Features 15% | 100 thermostat, AC backup, separate or tilting panel | 70 thermostat, AC backup |
| Warranty 25% | 58 15-year warranty | 58 15-year warranty |
Specifications
| QuietCool AFR SLR-40 Solar Roof Fan | QuietCool AFR SLR-25 Solar Roof Fan | |
|---|---|---|
| Airflow | ||
| Mount | Roof | Roof |
| Airflow | 1,085 CFM | 927 CFM |
| Attic area | 1,450 sq ft | 1,200 sq ft |
| Motor | 24V brushless DC, IP67 | 24V brushless DC, IP67 |
| Power | ||
| Panel | 40 W | 25 W |
| Separate or tilting panel | Yes | No |
| Thermostat | Yes | Yes |
| AC backup | Yes | Yes |
| Build | ||
| Warranty | 15 years | 15 years |