HD55S vs HDi65S:
gravity or pump?

01 · Models

AlorAir HD55S vs HDi65S: the models

This comparison covers the standard white Sentinel HD55S and black Sentinel HDi65S. Wi-Fi versions are separate products. The HDi65S name does not mean a 65-pint rating: the manufacturer specifies 55 US pints per day at 80 °F and 60% relative humidity. [3][4]

Browse the dehumidifier guides for other equipment categories.

Images are not shown to a common scale.

02 · Drainage

Where the water goes

The HD55S manual calls for a continuous downward slope, without loops or low spots. When that route is not possible, the manual allows an external condensate pump with its own power supply. [1]

Water-flow diagrams based on the HD55S and HDi65S manuals. [1][2]

The HDi65S pump starts automatically as water reaches the trigger level. The Drain button runs an additional pump-out, such as before moving or storing the unit. It does not need pressing for each operating cycle. A separate outlet also allows gravity drainage; the manual requires that outlet to be plugged when using the pump. [2]

For connection options, see the dehumidifier drainage guide.

03 · Comparable specifications

Matching capacity and cabinet ratings

Both models are rated at 55 pints/day under AHAM conditions and 120 pints/day at 90 °F / 90% RH. These are different test conditions. The guide to pint ratings explains the difference. [3][4]

Dimensions, airflow, weight, refrigerant and filter are from the specifications dated December 18 and 19, 2025. Drainage is checked against the manuals. [1][2][5][6]

The 13.3-inch cabinet height is not the full installation clearance. The manuals call for at least 6 inches at the air inlet and 36 inches at the outlet. For placement, see the crawl-space dehumidifier guide. [1][2]

04 · Product versions

Check R32 and the ENERGY STAR record

ENERGY STAR record 4005597 names Sentinel HD55S as the model and lists Sentinel HDI65S under additional model information. It specifies HFC-32 (R32) refrigerant and an integrated energy factor of 2.08 L/kWh. [7]

Before paying, ask the seller for a photo of the offered unit’s rating label and confirmation of its refrigerant. If you want the certified R32 version, match it to the ENERGY STAR record. A matching product name alone does not confirm the version in the shipment.

05 · What is included and care

The remote controller is an optional accessory

Both selected store listings include the dehumidifier, a MERV-1 filter, manual and drain hose. The manuals describe the wired remote controller as an optional accessory. It can be placed outside the crawl space to control the unit and view readings. [8][9][1][2]

The 2023 HDi65S manual lists MERV-8, while the 2025 specification and store packing list say MERV-1. Check the installed filter and compatibility with the unit’s version before ordering a replacement. [2][6][9]

The HDi65S also has a pump assembly to maintain. Its manual covers testing drainage and checking for a blockage when error E4 appears. The pump is accessed through a separate panel; disconnect power before internal servicing. [2]

06 · Choosing a model

Choose around the drain route

With matching stated water-removal ratings, the HDi65S advantage here is its built-in drainage pump. To compare other series, see the AlorAir dehumidifier review.