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 2.8. The QuietCool AFR SLR-40 Solar Roof Fan leads on features. The QuietCool AFR SLR SMT 50W Roof Fan wins on panel.
QuietCool AFR SLR SMT 50W Roof Fan
#11 in Roof mountFull review
For a homeowner who wants to watch and control attic conditions from a phone and run around the clock. Buyers after the most airflow per dollar should look elsewhere.
Amazon $439.99 QuietCool $439$439
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 features (thermostat, AC backup, separate or tilting panel vs thermostat, AC backup).
- Choose the QuietCool AFR SLR SMT 50W Roof Fan for panel (50 W panel vs 40 W panel).
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 SMT 50W Roof Fan |
|---|---|---|
| Overall rating | 3.3/5 | 2.8/5 |
| Value 25% | 22 $0.40 per CFM ($439, 1,085 CFM) | 24 $0.39 per CFM ($439, 1,119 CFM) |
| Airflow 15% | 26 1,085 CFM | 27 1,119 CFM |
| Panel 20% | 60 40 W panel | 80 50 W panel |
| Features 15% | 100 thermostat, AC backup, separate or tilting panel | 70 thermostat, AC backup |
| Warranty 25% | 58 15-year warranty | 0 warranty not published, scored as none |
Specifications
| QuietCool AFR SLR-40 Solar Roof Fan | QuietCool AFR SLR SMT 50W Roof Fan | |
|---|---|---|
| Airflow | ||
| Mount | Roof | Roof |
| Airflow | 1,085 CFM | 1,119 CFM |
| Attic area | 1,450 sq ft | 1,500 sq ft |
| Motor | 24V brushless DC, IP67 | DC |
| Power | ||
| Panel | 40 W | 50 W |
| Separate or tilting panel | Yes | - |
| Thermostat | Yes | Yes |
| AC backup | Yes | Yes |
| Build | ||
| Warranty | 15 years | - |
| Released | - | 2026-06 |