QuietCool AFG SLR-40 Solar Gable Fan
#1 in Gable mountFull review
The best documented gable fan here, for an attic with a gable vent big enough to let its air out. Its long warranty and included adapter justify the price.
QuietCool $359$359
The QuietCool AFG SLR-40 Solar Gable Fan is the better solar attic fan overall, rated 3.7 to 3.3. The QuietCool AFG SLR-40 Solar Gable Fan leads on features. The QuietCool AFG SLR SMT 50W Gable Fan wins on panel.
QuietCool AFG SLR SMT 50W Gable Fan
#3 in Gable mountFull review
For a gable vented attic where the owner wants app control and steady airflow around the clock, at the same price as the simpler AFG SLR-40.
Amazon $359$359
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 AFG SLR-40 Solar Gable Fan for features (thermostat, AC backup, separate or tilting panel vs thermostat, AC backup).
- Choose the QuietCool AFG SLR SMT 50W Gable 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 gable mount solar attic fan; a clear win is highlighted. How we rank explains each one.
| Factor weight | QuietCool AFG SLR-40 Solar Gable Fan | QuietCool AFG SLR SMT 50W Gable Fan |
|---|---|---|
| Overall rating | 3.7/5 | 3.3/5 |
| Value 25% | 54 $0.23 per CFM ($359, 1,566 CFM) | 61 $0.20 per CFM ($359, 1,780 CFM) |
| Airflow 15% | 51 1,566 CFM | 62 1,780 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 AFG SLR-40 Solar Gable Fan | QuietCool AFG SLR SMT 50W Gable Fan | |
|---|---|---|
| Airflow | ||
| Mount | Gable | Gable |
| Airflow | 1,566 CFM | 1,780 CFM |
| Attic area | 2,000 sq ft | 2,250 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 | - | 2026-09 |