Best Dehumidifier for an Apartment: The Tank Is the Real Limit

Q: What size dehumidifier do I need for an apartment?

For 500 to 1,200 sq ft at 55 to 60 percent RH, a 20 to 30-pint unit on the 2019 DOE scale covers it, which is $150 to $260. Go to 35 to 50 pints only for a ground-floor or garden unit with walls below grade.

Q: How do I drain a dehumidifier in an apartment with no floor drain?

Raise the unit on a sturdy stand so its drain port sits above the tub or shower rim, then run a sloped hose into it, which costs $8 to $15 for the hose. If the machine has to stay at floor level, buy a model with a built-in pump (plus $40 to $70) or an external condensate pump ($50 to $80) to push water up to a sink. Nothing here drills anything, so it stays rental-safe.

Q: Will a dehumidifier make my apartment hot or spike the electric bill?

It adds a little heat, because a compressor unit returns warm dry air and can lift a small closed room a few degrees. At 250 to 450 W and 10 hours a day, expect roughly $10 to $25 a month at US residential rates. A humidistat cuts that by idling the machine once it hits target.

Q: Do I still need a dehumidifier if I have air conditioning?

Often no, in mid-summer, because an AC removes moisture as a side effect of cooling. The gaps are spring and fall, when it is 65 to 72 F and humid so the AC barely runs, and any room it does not reach. Put a $15 to $25 hygrometer in the damp room for two days; if it stays under 50 percent RH with the AC alone, save your money.

Updated August 2026 · Editorial team · Topic: mold & moisture control / dehumidifiers

Best Dehumidifier for an Apartment: The Tank Is the Real Limit — Dehumidifiers

The beep comes at 4 a.m. — tank full — and the compressor shuts off. You carry two liters of water to the bathroom in the dark, dump it in the tub, go back to bed. Third night this week. Nothing is broken: a 30-pint machine in a damp one-bedroom fills a 1.6-gallon tank in under a day, and a rental has no floor drain to send it to. In an apartment you don't pick the unit on capacity — you pick it on noise and on where the water goes.

Short answer: For an apartment of 500–1,200 sq ft, buy a 20–30-pint unit on the 2019 DOE scale ($150–260) — a 50-pint is a basement machine and short-cycles here. Two specs decide it: noise under 45 dBA if you sleep in the room, and drainage, since a gravity hose works only when the port sits above the tub drain — otherwise pay $40–70 for a built-in pump. Hold 30–50 %RH per EPA, never above 60 %RH.

Reviewed by the DampGuard Lab editorial team. We publish plain specs, %RH targets and EPA-based removal steps so you can judge for yourself — no remediation upsell. General information only, not medical advice: mold larger than 10 sq ft, hidden mold in walls or HVAC, or any health concern belongs with a certified mold professional.

Why "buy big to be safe" backfires in an apartment

Nearly every dehumidifier chart online was written for a basement, and its advice — get more pints than you think you need — is the wrong instinct four floors up. Since the 2019 DOE rescale, capacity is measured at 65 °F and 60 %RH instead of the old 80 °F test, so a machine that once printed "70 pints" now prints "50." A 50-pint unit today is what a 70-pint one used to be: sized for an open, cool, wet basement, not a heated 800 sq ft flat.

Apartment moisture also arrives differently. A basement pulls water through concrete and soil; an apartment makes its own. Laundry dried on a rack releases up to a gallon (8 pints) over a day or two, and each occupant adds roughly 2–3 pints a day. Real, but a steady trickle — not the 30+ pints a day a slab basement hands you in July.

Put an oversized machine on that trickle and it hits target in twenty minutes, stops, drifts up, restarts. Each restart is the loud part: compressor kick, then fan. In a studio you hear every cycle, and the neighbor below feels it through the floor deck. A 20–30-pint unit runs longer and steadier at lower fan speed — quieter, and better at holding a stable %RH.

Sizing and price by apartment

Match capacity to floor area and to how damp the place actually is — musty smell, morning condensation on the glass, a hygrometer over 60 %RH. These are 2019-scale pints; listings recycle old numbers, so check the box for "DOE 2019" or AHAM certification.

Apartment	Typical area	Condition	Capacity (2019 DOE)	Price
Studio	350–600 sq ft	Slightly damp, 55–60 %RH	20 pints	$150–200
One-bedroom	600–900 sq ft	Damp, musty closet or bath	20–30 pints	$170–230
Two-bedroom	900–1,300 sq ft	Damp, doors kept open	30 pints	$190–260
Ground-floor / garden	600–1,200 sq ft	Wet, walls below grade	35–50 pints	$220–300
One problem room	Under 250 sq ft	Closet, bath, cabinet	Peltier mini or desiccant	$15–60

One machine dries only the air it reaches: run it where the damp is, doors open.

The drainage decision — the part rentals fail

This is where apartment buyers get stuck: no floor drain, no standpipe you're allowed to tap, no permission to drill. Four ways out, only one of them free.

Drain option	What it needs	Emptying	Cost	Landlord-safe?
Tank only	Nothing	Every 1–3 days once %RH is stable; twice on day one	Included	Yes
Gravity hose to the tub	Port above the drain: a stand, hose sloped the whole way	Never	$8–15 hose	Yes, nothing permanent
Built-in pump	Outlet; hose routed up to a sink	Never	+$40–70	Yes
External condensate pump	Second outlet, reservoir under the unit	Never	$50–80	Yes

The failure everyone repeats: buy the hose, run it flat across the floor to the bathroom, and the tank still fills. Gravity needs continuous downhill fall from port to drain. A unit on the floor cannot push water up into a sink — that's a pump's job, which is why "continuous drainage" appears on spec sheets at two very different prices.

What to check before you buy

Start with a $15–25 hygrometer, not a machine: leave it in the room 48 hours, reading morning and evening. Under 50 %RH with no musty smell means airflow and a bath fan are the fix, not a $200 appliance. Above 60 %RH, buy — EPA puts the indoor target at 30–50%. Then four numbers:

dBA. 45–48 is fine in a living room; where you sleep, look for 42 or under. A listing that hides the number is telling you something.
Tank vs. capacity. A 30-pint machine with a 0.8-gallon (6.4-pint) tank means two trips a day through the first wet week; a 1.6-gallon tank halves that.
Wattage. Roughly 250–450 W. At 10 hours a day and $0.13–0.20 per kWh, about $10–25 a month.
Humidistat and auto-restart. Set-and-hold at 50% beats a machine that runs flat out and needs re-arming after a power blip.

If a wall is visibly moldy rather than damp, sizing is the wrong conversation. EPA's rule of thumb: patches under about 10 square feet are DIY cleanup on hard, non-porous surfaces; anything larger, or inside a wall cavity or the building's HVAC, belongs to the property manager and a certified pro. A dehumidifier is prevention, never remediation.

Field note: We don't run a test chamber and won't pretend otherwise — these numbers come from DOE capacity ratings, manufacturer spec sheets and EPA moisture guidance, not from units we benched. In apartments the complaints don't cluster on capacity: it's the pump-versus-gravity confusion above, plus vibration. A compressor on bare hardwood or tile turns the floor into a soundboard and sends a hum into the ceiling below. A $10 anti-vibration mat, or a rug, fixes a noise problem people usually solve by returning the unit.

Common mistakes

Buying a 50-pint because it's on sale. On the 2019 scale that's a basement unit. In an apartment it short-cycles: more startups, more noise, no better humidity control.
Assuming continuous drainage means no pump. Most units drain by gravity only. If the hose runs level or uphill to reach the tub, you need a pump, $40–80.
Closing the bedroom door and expecting whole-apartment drying. A closed door is a wall as far as the machine is concerned.
Running it against an active leak. A drip from upstairs or a failed shower pan refills the air faster than any appliance clears it. Report it, fix the source, then dry.

FAQ

What size dehumidifier do I need for an apartment?

For 500–1,200 sq ft at 55–60 %RH, a 20–30-pint unit on the 2019 DOE scale covers it — $150–260. Go to 35–50 pints only for a ground-floor unit with walls below grade. Our sizing guide walks through footage and dampness.

How do I drain a dehumidifier in an apartment with no floor drain?

Raise the unit on a stand so the drain port sits above the tub rim, then run a sloped hose into it — $8–15 for the hose, nothing drilled. If it must stay at floor level, a built-in pump (+$40–70) or external condensate pump ($50–80) pushes water up to a sink.

Will a dehumidifier make my apartment hot or spike the electric bill?

It adds a little heat: a compressor unit returns warm, dry air and can lift a small closed room a few degrees. At 250–450 W and 10 hours a day, expect roughly $10–25 a month. The runtime and kWh math shows how a humidistat trims that by idling at target.

Do I still need a dehumidifier if I have air conditioning?

Often no in mid-summer: an AC removes moisture as a side effect of cooling. The gaps are spring and fall, when it's 65–72 °F and humid so the AC barely runs. Put a $15–25 hygrometer in the damp room for two days — under 50 %RH on AC alone, save your money.

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General information on home moisture control, not medical or professional remediation advice. Mold covering more than about 10 square feet, hidden growth inside walls or HVAC, or any related health concern warrants a certified specialist. Prices, capacities and specifications vary by model and region.