AHAM PPD
AHAM PPD is a standardized, moderate-condition moisture-removal rating. It is useful when comparing products because it gives buyers a more consistent context than an advertised maximum number alone.
Specification guide
AHAM PPD vs Maximum PPD: Why Dehumidifiers Have Different Pint Ratings
A crawl-space dehumidifier may be marketed with one pint-per-day number while also publishing a different AHAM rating. Those numbers describe different test contexts, so they should not be treated as interchangeable.
What the two ratings mean
Maximum or saturation PPD
Maximum or saturation PPD reflects removal under very humid conditions. It can be useful context, but it should not be used by itself to decide whether one unit is better or correctly sized for a crawl space.
Buyer confusion often shows up as questions like whether a 70-pint unit and a 145-pint unit are truly different sizes. In the DrySpace database, Moiswell Defender M70 and MP70 both show 70 PPD AHAM and 145 PPD maximum removal, so the numbers are describing two rating conditions for the same models rather than one simple class label.
Verified ratings in the DrySpace database
| Manufacturer | Model | AHAM PPD | Maximum PPD | Manufacturer max coverage | Airflow | Research |
|---|---|---|---|---|---|---|
| Moiswell | Aegis HP110 | 53 pints/day | 120 pints/day | 4,500 sq ft | 180 CFM | Product page |
| Moiswell | Defender M70 | 70 pints/day | 145 pints/day | 6,000 sq ft | 206 CFM | Product page |
| Moiswell | Defender MP70 | 70 pints/day | 145 pints/day | 6,000 sq ft | 206 CFM | Product page |
| Moiswell | Aegis H150 | 70 pints/day | 155 pints/day | 6,500 sq ft | 253 CFM | Product page |
| Moiswell | Aegis HP150 | 70 pints/day | 155 pints/day | 6,500 sq ft | 253 CFM | Product page |
| AlorAir | Sentinel HD35P | 35 pints/day | 70 pints/day | 1,000 sq ft | 115 CFM | Product page |
| AlorAir | Sentinel HD55S | 55 pints/day | 120 pints/day | 1,300 sq ft | 130 CFM | Product page |
| AlorAir | Sentinel HD55P | 55 pints/day | 120 pints/day | 1,300 sq ft | 153 CFM | Product page |
| AlorAir | Sentinel HD90 | 90 pints/day | 198 pints/day | 2,600 sq ft | 210 CFM | Product page |
| AlorAir | Sentinel HDi90 | 90 pints/day | 198 pints/day | 2,600 sq ft | 210 CFM | Product page |
Comparison context, not a sizing guarantee
Pint-per-day ratings help normalize product comparison, but actual crawl-space moisture load also depends on sealing, temperature, drainage, air leakage, climate, height, and water intrusion.
For product selection, use pint ratings alongside drainage setup, operating temperature, manufacturer-reported coverage, and source verification status.
Continue researching
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How DrySpace handles incomplete data
DrySpace uses manufacturer documentation and official sources already represented in the product database. Verification dates are recorded, unknown fields stay marked as not verified, and conflicting manufacturer values are surfaced rather than resolved by guessing.
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