QuietCool AFR SLR-40 Solar Roof Fan
#9 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 2.3. The QuietCool AFR SLR-40 Solar Roof Fan leads on warranty, features and panel. The QuietCool AFR SLR-40 Solar Roof Fan costs $21.54 less ($439 vs $460.54).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Master Flow PRSOLAR2 Solar Roof Vent
#18 in Roof mountFull review
For a medium attic where a low profile look and a GAF warranty with labor cover matter more than airflow per dollar.
Amazon $460.54$460.54
Which should you buy?
- Choose the QuietCool AFR SLR-40 Solar Roof Fan for warranty (15-year warranty vs 6-year warranty), features (thermostat, AC backup, separate or tilting panel vs thermostat) and panel (40 W panel vs 35 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 | Master Flow PRSOLAR2 Solar Roof Vent |
|---|---|---|
| Overall rating | 3.3/5 | 2.3/5 |
| Value 25% | 22 $0.40 per CFM ($439, 1,085 CFM) | 0 $0.61 per CFM ($460.54, 750 CFM) |
| Airflow 15% | 26 1,085 CFM | 8 750 CFM |
| Panel 20% | 60 40 W panel | 50 35 W panel |
| Features 15% | 100 thermostat, AC backup, separate or tilting panel | 40 thermostat |
| Warranty 25% | 58 15-year warranty | 21 6-year warranty |
Specifications
| QuietCool AFR SLR-40 Solar Roof Fan | Master Flow PRSOLAR2 Solar Roof Vent | |
|---|---|---|
| Airflow | ||
| Mount | Roof | Roof |
| Airflow | 1,085 CFM | 750 CFM |
| Attic area | 1,450 sq ft | 1,070 sq ft |
| Motor | 24V brushless DC, IP67 | - |
| Power | ||
| Panel | 40 W | 35 W |
| Separate or tilting panel | Yes | - |
| Thermostat | Yes | Yes |
| AC backup | Yes | No |
| Build | ||
| Weight | - | 23 lb |
| Warranty | 15 years | 6 years |