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.

Research by Josiah Gavin

What the two ratings mean

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.

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	Rated/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
AlorAir	Helios D35	35 pints/day	70 pints/day	1,000 sq ft	97 CFM	Product page
AlorAir	Galaxy 60	60 pints/day	145 pints/day	1,800 sq ft	165 CFM	Product page
AlorAir	Galaxy 60P	60 pints/day	145 pints/day	1,800 sq ft	165 CFM	Product page
AlorAir	Galaxy 85P	85 pints/day	180 pints/day	2,300 sq ft	194 CFM	Product page
AlorAir	Sentinel HDi100	100 pints/day	220 pints/day	2,900 sq ft	250 CFM	Product page
AprilAire	E050	50 pints/day	Not verified	1,600 sq ft	145 CFM	Product page
AprilAire	E070	70 pints/day	Not verified	2,200 sq ft	200 CFM	Product page
AprilAire	E080	80 pints/day	Not verified	4,400 sq ft	185 CFM	Product page
AprilAire	E100	100 pints/day	Not verified	5,500 sq ft	280 CFM	Product page
AprilAire	E130	130 pints/day	Not verified	7,200 sq ft	310 CFM	Product page
Argendon	Shield 35M	35 pints/day	70 pints/day	1,000 sq ft	115 CFM	Product page
Argendon	Shield 35P	35 pints/day	70 pints/day	1,000 sq ft	115 CFM	Product page
Argendon	Sandidry 55C	55 pints/day	120 pints/day	1,300 sq ft	153 CFM	Product page
Argendon	Shield 60	60 pints/day	145 pints/day	1,800 sq ft	185 CFM	Product page
Argendon	Shield 60P	60 pints/day	145 pints/day	1,800 sq ft	165 CFM	Product page
Argendon	Shield 85P	85 pints/day	180 pints/day	2,300 sq ft	194 CFM	Product page

Useful examples

Moiswell

Defender M70

70 pints/day / 6,000 sq ft

Moiswell

Defender MP70

70 pints/day / 6,000 sq ft

AlorAir

Sentinel HD90

90 pints/day / 2,600 sq ft

AlorAir

Sentinel HDi90

90 pints/day / 2,600 sq ft

Moiswell Defender M70 vs Defender MP70 AlorAir Sentinel HD90 vs Sentinel HDi90

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

Compare verified products

Filter and compare AHAM, maximum PPD, airflow, pump status, and coverage.

Use the sizing assistant

Check manufacturer-reported coverage, drainage needs, and temperature constraints.

Estimate operating cost

Use wattage, runtime, and local electricity rate to estimate cost.

Browse research guides

Find decision guides for specifications, drainage, sizing, and brand comparisons.

Pump vs gravity drain

Understand how drainage route can affect product configuration.

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.

Browse all individual product pages in the product research directory.