Window condensation is a humidity problem that shows up on glass because glass is the coldest surface in the room. When warm indoor air touches a surface colder than its dew point, the water vapor in it turns back into liquid. In winter, that happens on windows first.
A dehumidifier for window condensation works by lowering the amount of water in the air, which lowers the dew point, so the glass is no longer cold enough to collect water. ENERGY STAR's guidance for cold climates is to keep humidity in the 30% to 40% range during the heating season to prevent window condensation.
Why windows get condensation
| Cause | Why it causes condensation | Fix |
|---|---|---|
| Cold weather | Glass temperature drops below the room air's dew point | Lower indoor humidity to 30 to 40% |
| Cooking, showers, drying laundry | Adds lots of water vapor quickly | Use exhaust fans; vent the dryer outside |
| Sleeping in a closed bedroom | People breathe out moisture all night | Crack the door, run a small dehumidifier |
| Single-pane or failing double-pane windows | Glass is colder than good insulated glass | Storm windows, window film, or replacement |
| Curtains closed tight against glass | Traps cold, still air at the window | Leave a gap for air circulation |
| Humidifier set too high | Adds more moisture than winter windows can handle | Turn it down or off |
Will a dehumidifier stop window condensation?
Usually, yes, if the condensation comes from high indoor humidity rather than from a leak. Bring the room to around 40% in winter and most windows stay dry. Very cold nights can still cause some condensation at the bottom edge of poorly insulated windows even at reasonable humidity, which is a window problem, not a humidity problem.
Best dehumidifier for condensation
| Pick | Capacity | Coverage | Pump | Noise | ENERGY STAR | Price tier | |
|---|---|---|---|---|---|---|---|
| Best for bedrooms Midea Cube 20 | 20 pints/day (DOE) | Up to 1,500 sq ft (maker claim); Sylvane suggests about 300 sq ft | No | Not published by Midea for this SKU | Yes | $$$ | Check price |
| Best for living areas Midea Cube 35 | 35 pints/day (DOE) | Up to 3,500 sq ft (maker claim) | No | Not published | Yes | $$$ | Check price |
| Best for whole floor Midea Cube 50 (no pump) | 50 pints/day (DOE) | Up to 4,500 sq ft (Amazon listing) | No | Not published for this SKU (RTINGS measured the pump version at 54 to 56 dBA) | Yes | $$$ | Check price |
| Best budget Hisense 25 | 25 pints/day (DOE) | 700 to 1,500 sq ft (sources differ) | No | Not published | Not stated | $$ | Check price |
| Best for closets Eva-Dry E-333 | See notes | Spaces up to 333 cubic feet | No | Silent (no fan or compressor) | No | $ | Check price |
Best for bedroom window condensation
Midea Cube 20 Pint Smart Dehumidifier
Most window condensation complaints come from bedrooms. A 20 pint unit is the right size for one room, and the Midea Cube 20's Wi-Fi app lets you set the target humidity to 40% and check it from bed.
| Model number | MAD20S1QWT |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 20 pints/day |
| Coverage | Up to 1,500 sq ft (maker claim); Sylvane suggests about 300 sq ft |
| Built-in pump | No |
| Wi-Fi / app | Yes |
| ENERGY STAR | Yes |
| Noise | Not published by Midea for this SKU |
| Bucket / capacity | 3.2 gal (12 L) expandable bucket, per the user manual |
| Warranty | 1-year limited (Sylvane listing) |
| ENERGY STAR test data | 20.16 pints/day, IEF 1.70 L/kWh, about 249 kWh/yr (record for MAD20S1QWT) |
| Price tier | Mid (about $200 to $400) |
Pros
- Right size for one room
- App humidity readout
Cons
- No pump
- Not silent
Spec sources (checked 2026-11-11): Midea US product page MAD20S1QWT; Sylvane listing (suggested room size, warranty); User manual (capacity, tank); ENERGY STAR certified product record (MAD20S1QWT).
Best for living areas
Midea Cube 35 Pint Dehumidifier
For an open living room and kitchen, step up to 35 pints. The Midea Cube 35 is ENERGY STAR certified at 2.01 L/kWh.
| Model number | MAD35S1QWT (white) / MAD35S1QGR (gray) |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 35 pints/day |
| Coverage | Up to 3,500 sq ft (maker claim) |
| Built-in pump | No |
| Wi-Fi / app | Yes |
| ENERGY STAR | Yes |
| Noise | Not published |
| Weight | 39.62 lb (retailer listing) |
| Warranty | 1 year (retailer listing) |
| ENERGY STAR test data | 35.82 pints/day, IEF 2.01 L/kWh, about 378 kWh/yr (record for MAD35S1QWT-A) |
| Price tier | Mid (about $200 to $400) |
Pros
- 35 pints/day
- Efficient
Cons
- No pump
Spec sources (checked 2026-11-11): Midea US product page MAD35S1QWT; Electronic Express listing MAD35S1QWT; ENERGY STAR certified product record (MAD35S1QWT-A).
Best for a whole floor
Midea Cube 50 Pint Smart Dehumidifier (no pump)
If every window on a floor fogs up, a 50 pint unit placed centrally with doors open is the most effective portable fix.
| Model number | MAD50S1QWT |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 50 pints/day |
| Coverage | Up to 4,500 sq ft (Amazon listing) |
| Built-in pump | No |
| Wi-Fi / app | Yes |
| ENERGY STAR | Yes |
| Noise | Not published for this SKU (RTINGS measured the pump version at 54 to 56 dBA) |
| Bucket / capacity | Expandable large-capacity bucket (same Cube design as the pump version) |
| Drain | Bucket or gravity drain hose (no pump) |
| App | Wi-Fi, works with Alexa (Amazon listing) |
| ENERGY STAR test data | 49.67 pints/day, IEF 2.01 L/kWh, about 515 kWh/yr (record for MAD50S1QWT-A) |
| Price tier | Mid (about $200 to $400) |
Pros
- 50 pints/day
- ENERGY STAR
Cons
- Larger, louder
Spec sources (checked 2026-11-11): Amazon listing B0GL7B1FC8 (model MAD50S1QWT); Midea US store page MAD50S1QWT; ENERGY STAR certified product record (MAD50S1QWT-A).
Best budget pick
Hisense 25 Pint (30 Pint pre-2019) Dehumidifier
A basic 25 pint unit is enough for one room with moderate condensation.
| Model number | DH3020K1W |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 25 pints/day |
| Coverage | 700 to 1,500 sq ft (sources differ) |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Bucket / capacity | 1 gal bucket |
| Old (pre-2019) rating | 30 pints/day |
| Fan speeds | 1 |
| Price tier | Value (about $100 to $200) |
Pros
- Low price tier
Cons
- Small bucket
Spec sources (checked 2026-11-11): Hisense USA product page; Hisense Canada product page.
Best for closets on exterior walls
Eva-Dry E-333 Renewable Mini Dehumidifier
Closets on cold outside walls get condensation and mildew too. A small renewable desiccant handles that silently.
| Model number | E-333 |
|---|---|
| Type | Renewable desiccant (cordless) |
| Coverage | Spaces up to 333 cubic feet |
| Built-in pump | No |
| Wi-Fi / app | No |
| ENERGY STAR | No |
| Noise | Silent (no fan or compressor) |
| Bucket / capacity | Absorbs about 4 to 6 oz before it needs renewing (retailer listing) |
| How you renew it | Plug it into a wall outlet to dry the silica gel out; maker FAQ caps renewal at 18 hours of plug-in time |
| Size | 6.25 x 1.25 x 4.75 in |
| Price tier | Budget (under about $100) |
Pros
- Silent
- Reusable
Cons
- Very small capacity
Spec sources (checked 2026-11-11): Hydrobuilder listing E-333; Eva-Dry FAQ.
Desiccant vs compressor in winter
Compressor dehumidifiers chill a coil to pull water out of the air, so they work best in warm rooms; portables are tested at 65F, and ENERGY STAR suggests a model specified for lower temperatures if a space is usually cooler than that. Desiccant dehumidifiers use a moisture-absorbing material instead of a cold coil, so they keep working in cold rooms. The trade-off is that they generally use more power and warm the room slightly. For a heated bedroom or living room, a compressor unit is the efficient choice. For an unheated room, garage or porch, consider a desiccant model.
Other fixes
- Run bathroom and kitchen exhaust fans for 15 to 20 minutes after showers and cooking.
- Open curtains during the day and leave a gap at night so warm air reaches the glass.
- Turn down or switch off humidifiers in winter.
- Add storm windows or window insulation film to single-pane windows.
- Wipe sills dry in the morning to protect paint and wood until humidity is under control.
Frequently asked questions
Does a dehumidifier stop condensation on windows?
Where should a dehumidifier go for condensation?
What humidity stops condensation?
Sources
- ENERGY STAR: Dehumidifiers buying guidance and sizing chart
- ENERGY STAR: Dehumidifier testing and capacity