Water Damage Dehumidifier: LGR vs Desiccant, Specs and Cost

Air movers do not remove water from a building. They move it from carpet, drywall and framing into the room air, and the dehumidifier takes it out of the air and down a drain. Without one, a closed room climbs toward saturation and evaporation stalls. EPA's mold and moisture guide sets the urgency: EPA says to dry wet materials within 24 to 48 hours.

What the machine is for on a water loss

Early in a dry any dehumidifier collects plenty. Late in the dry, when the remaining water is inside a subfloor or a stud, the air must be held drier than the material for the material to give it up. That low-grain end is where machine types separate. How the whole dry is planned is on our structural drying explainer; whole-home units for routine basement humidity are an HVAC purchase outside this page. More is on the water hub.

Refrigerant, LGR and desiccant

Type	How it removes water	Where it struggles	Typical use
Conventional refrigerant	Air crosses a cold coil and vapour condenses.	Output falls as air dries; the IICRC factor sheet gives it no Class 4 factor.	Small or early-stage losses
Low grain refrigerant (LGR)	Coil built to keep condensing at lower humidity.	Per R&R Magazine, cannot dry air below a 32 F dew point.	Most residential losses
Desiccant	A desiccant adsorbs vapour; heated reactivation air carries it out.	Per R&R, electric models give about 1 to 2 pints per kilowatt.	Cold spaces, dense materials, crawl spaces

How low each type can take the air

Per the NWS formulas, saturated air at 32 F holds about 26 grains per pound. That is the floor R&R Magazine puts under an LGR, because a colder coil frosts instead of condensing. The same article says desiccants reach single-digit grains, about 4% RH at 70 F (about 4 grains per the same formulas), and are the only reasonable option below 65 F.

According to Legend Brands, which makes Dri-Eaz, its LGRs are tested at 80 F and 20% RH and 70 F and 30% RH, the lowest-grain conditions an LGR meets on a job: about 30 and 33 grains per the NWS formulas.

AHAM, saturation and the 2019 DOE change

According to Legend Brands, which makes Dri-Eaz, the Association of Home Appliance Manufacturers set a 24 hour test at 80 F and 60% RH in 1992, and restoration makers print that AHAM figure because Xactimate prices refrigerant units by capacity range. According to the same page, the 90 F and 90% “Max” rating is a unit’s highest capacity and is not useful in restoration.

Rating	Test condition	Grains per pound	Where you meet it
AHAM	80 F, 60% RH	92	Restoration spec sheets, IICRC sizing, Xactimate ranges
Saturation or Max	90 F, 90% RH	195	Restoration headline figure
DOE portable	65 F, 60% RH	55	Household cartons since 2019
DOE whole-home	73 F, 60% RH	73	Ducted household units

What DOE changed

Per the DOE test procedure, 10 CFR 430 Appendix X1, portable units are tested at 65 F and 60% RH and whole-home units at 73 F and 60% RH. Per the eCFR record it was published 31 July 2015 and amended 26 July 2023. The standards in 10 CFR 430.32(v) apply to units made on or after 13 June 2019. Per ENERGY STAR, the cooler test lowered printed capacities from early 2020. The hardware did not shrink; the test got harder.

Old rating, through 2019 (pints/day)	Approximate new rating, 2020 (pints/day)
30	20
40	25
50	30
55	30 to 35
60	35
70	40 to 45
90	55

Restoration makers still print AHAM, so compare restoration units with each other at AHAM and never against a household carton.

Choosing a dehumidifier for water damage: eight spec sheets

Six Dri-Eaz and two Phoenix units, chosen because both makers publish amp draw and Xactimate codes beside pints per day. Inclusion is not a recommendation.

Unit, per the maker’s page	Type	Pints/day, AHAM	Pints/day, 90 F 90%	Amps	CFM	Xactimate code
Dri-Eaz DrizAir 1400	Refrigerant, not sold as LGR	64	130	4.7	215	WTRDHM
Dri-Eaz Revolution LGR	LGR	80	144	5.5	180	WTRDHM>L
Dri-Eaz LGR 5000Li	LGR	80	164	5.1	215	WTRDHM>L
Dri-Eaz LGR 6000Li	LGR	100	219	6.5	320	WTRDHM>L
Dri-Eaz LGR 7000XLi	LGR	130	235	8.8	280	WTRDHM>>XL
Dri-Eaz LGR 3500	LGR	170	270	10.8	400	WTRDHM>>>XXL
Phoenix DryMAX XL Pro+	LGR	135	Not published	6.7	300	Not on page
Phoenix D385	Desiccant	130	Not published	24 on 2 cords	385	WTRDHMD

Spec sheets drift. Per the older LGR 3500i spec sheet, that unit made 240 pints at 90 F and 90% on 11.2 amps; per the current Dri-Eaz LGR 3500 page, it makes 270 on 10.8 amps, with AHAM still 170. Log the model year.

Sizing, in one sentence

The IICRC dehumidification factor sheet divides cubic feet by a class factor to get pints per day, then by the unit’s AHAM rating to get the number of machines; the factor table and a worked room are on our structural drying page, and the AHAM column above, never the 90/90 one, is the number that goes in.

Placement, power and discharge

Per the Phoenix DryMAX BLE manual, the set-up is one line: unit inside the structure, hose to a drain or a very large container, windows and doors closed, wet area sealed off from unaffected rooms.

Check	What the published specs say	Why it matters
Closed chamber	Phoenix: close windows and doors, seal off the wet area.	Humid outdoor air adds water to remove.
Ground fault	Phoenix: a GFI is required in a wet area.	Standing water and cords share the floor.
Circuit load	Phoenix: the DryMAX BLE uses a 15 amp circuit and draws 5.7 amps at AHAM.	Add up dehumidifier and air mover amps per circuit.
Extension cords	Phoenix: 14 gauge up to 25 feet, 12 gauge beyond.	Thin cords drop voltage and run hot.
Pump lift and hose	Phoenix: lifts up to 23 feet; Dri-Eaz pages: 40 foot hose.	Decides where a basement unit can discharge.
Desiccant exhaust	Phoenix D385: 6 inch reactivation outlet duct required.	Wet reactivation air must leave the chamber.

Check the hose end on every visit: one that slipped out of a sink puts the water back on the floor. Per the Phoenix manual, flush units to limit biological growth. Per R&R Magazine, desiccant reactivation air is a quarter to two-thirds of process airflow and leaves hot and moist, so duct it outside.

Can a household dehumidifier dry a flooded room?

For a small clean spill caught early, sometimes. For a real flood, rarely, and the manuals say why.

Limit	Household unit	Restoration LGR
Capacity	Per ENERGY STAR, an old 70 pint unit rates 40 to 45 on today’s test.	80 to 170 AHAM pints across the Dri-Eaz LGRs above.
Temperature	41 to 89 F per the Frigidaire manual.	33 to 100 F per Dri-Eaz pages.
Drainage	Bucket; shuts down when full. Gravity hose optional.	Built-in pump and 33 to 40 foot hose.
Readouts	Room humidity only.	Temperature, RH and grain depression on Command Hub models.

Per a current Frigidaire use and care manual, performance “will fall greatly” outside its range, so a cold basement can defeat it. The real test is the materials: room humidity can fall while the subfloor stays wet, and EPA’s water damage table pairs dehumidifiers with fans for concrete and with gentle heat for wood. Our guides to drying wet carpet and basement flood cleanup cover the larger job.

Rent, buy or bill: what a dehumidifier costs

A day of drying has three prices: the rental counter, ownership and the contractor’s bill. Sunbelt Rentals pages opened for this article showed no public rate, so they are not quoted.

Renting: according to Simplex, a Canadian rental chain, a compact LGR rated 45 to 75 litres a day rents for $57 a day, $84 a weekend, $190 a week or $528 a month, plus a 9.9% damage waiver. Per that list a week costs 3.3 daily rates.

Unit as listed by Sylvane	Price	AHAM pints/day	Price per AHAM pint
Dri-Eaz DrizAir 1400	$2,249.99	64	$35.16
Dri-Eaz LGR 6000Li	$2,599.99	100	$26
Dri-Eaz LGR 5000Li	$2,698	80	$33.73
Dri-Eaz LGR 7000XLi	$3,499	130	$26.92
Phoenix DryMAX XL Pro	$3,799	n/a	n/a
Dri-Eaz LGR 3500i	$4,389.99	170	$25.82
Dri-Eaz DriTec 4000i (desiccant)	$4,615	n/a	n/a
Phoenix D385 (desiccant)	$5,056	130	$38.89

Billing: according to the Phoenix LGR specification chart, the daily rate for each Xactimate category runs from $54.59 for medium to $133.15 for XXL, and the Phoenix D385 page lists $230.00 for desiccant code WTRDHMD. The chart is undated and names no price list. According to Disaster Response by Ryan, a Michigan restoration firm, it bills $85 to $125 a day for standard LGRs and $150 to $250 for desiccants, three day minimum.

Our guides to how Xactimate pricing works and water damage restoration cost cover the rest of the bill.

Pick the machine in five questions

Work down in order; the first yes usually decides it.

• 1. Below about 65 F, or an unheated crawl space? Desiccant. Per R&R Magazine it is the only reasonable option there, and per Phoenix the D385 runs from minus 10 to 140 F.
• 2. Dense materials: hardwood, plaster, slab? LGR first, then desiccant or heat. The IICRC sheet gives conventional units no Class 4 factor.
• 3. An ordinary room of wet carpet and drywall? An LGR, sized on AHAM by the IICRC formula.
• 4. One small clean spill, same day, warm room? A household unit on a drain hose, if you measure the materials.
• 5. Only one or two household circuits? Count amps. Two smaller LGRs on separate circuits can beat one large unit that trips a breaker.

For contractors: the line item and the log

An adjuster wants the category billed, the unit on site and the readings for each billed day to agree.

Record	Detail	Why
Unit	Model, model year, AHAM rating, printed Xactimate code	Per Legend Brands, Xactimate ranges key off AHAM
Sizing	Cubic feet, class, IICRC factor, AHAM used	Shows the unit count was formula-based
Daily psychrometrics	Chamber, outdoor and outlet temperature and RH; grain depression	Shows water came out each day
Material readings	Against a dry standard from unaffected material	Ends the job, and the billing, on evidence
Power and discharge	Circuits, GFCI, hose termination	Covers a tripped breaker or a loose hose

Our guide to how long drying takes explains why readings, not the calendar, end the dry.

Questions people actually ask

How long should a dehumidifier run after water damage?

Until the wet materials, not the air, read dry against unaffected material of the same type. EPA says to dry wet materials within 24 to 48 hours to prevent mold, which sets the urgency, but a subfloor or slab can take days longer. Keep the room closed and stop on the readings.

Can a dehumidifier dry out water damage?

Not alone. It removes water from the air, so it needs extraction first and air movers to evaporate water out of materials. Together in a closed room they dry carpet, drywall and framing; a dehumidifier alone in a flooded room mostly lowers humidity while the materials stay wet.

Will a dehumidifier pull moisture out of the floor?

Indirectly. Holding the air drier than the floor lets water leave wood or concrete as vapour. EPA’s water damage table pairs dehumidifiers with fans for concrete and with gentle heat for wood. Dense floors are slow, and per R&R Magazine an LGR cannot take air below a 32 F dew point.

How often should I dump water from my dehumidifier?

Whenever the bucket fills. Per the Frigidaire manual cited here, the unit shuts down and lights a bucket full indicator, so after a flood that can be several times a day. A gravity hose to a drain avoids it. Restoration units pump; per Phoenix, its pump lifts up to 23 feet.

What is an LGR dehumidifier?

A low grain refrigerant unit built to keep condensing water as the air gets dry, which conventional units do poorly. Per the Dri-Eaz pages compared here, restoration LGRs are rated from 80 to 170 pints a day at the AHAM condition of 80 F and 60% RH.

When is a desiccant dehumidifier better for water damage?

When the space is cold, the target is very dry air, or materials are dense. Per R&R Magazine, desiccants are the only reasonable option below 65 F and reach single-digit grains per pound. They use more power and need their reactivation air ducted out.

What are the top-rated dehumidifiers for water damage recovery?

No independent body publishes a ranking. Compare spec sheets: AHAM pints, amps, operating range, pump lift and hose. Per the manufacturer pages in our table, the eight units run from 64 to 170 AHAM pints and 4.7 to 10.8 amps for single-cord models.

Does insurance pay for dehumidifier rental after water damage?

That depends on the policy wording and the cause of loss, so read the policy and ask the adjuster or your state insurance department. Xactimate carries dehumidifier line items by capacity. Our guide to whether homeowners insurance covers water damage explains the policy language.