Key points
- The EPA advises keeping indoor humidity below 60 percent, ideally between 30 and 50.
- A humidity meter is a small, inexpensive instrument, the EPA notes, and it tells you where you stand.
- Fix the source of water first: dry wet areas within 24 to 48 hours.
- Set the dehumidifier in the 45 to 50 percent band and let Auto mode hold it.
- Below 65°F, frost can form on the coils: keep the unit in the warmest part of the space.
The number to aim for
In its brief guide to mold and moisture, the U.S. Environmental Protection Agency advises keeping indoor humidity below 60 percent relative humidity, and ideally between 30 and 50 percent. Mold needs moisture to grow, and a room that sits above 60 percent for weeks gives it what it needs.
Basements sit low and cool, against soil that holds water, so they run damper than the rooms above them. In summer, warm outdoor air drifts in and cools against the walls and the floor, and the humidity climbs even when no water is visible. That is the job a dehumidifier does: it pulls the water out of the air before it settles on a wall.
Read the room before you buy
The EPA notes that relative humidity can be measured with a moisture or humidity meter, a small, inexpensive instrument sold at many hardware stores. Put one in the basement for a week in summer. If it reads in the 50s, the space is slightly damp. In the 70s or 80s it is very damp, and if the walls or the floor sweat, it is wet.
Condensation is a sign of high humidity too, the EPA says. Water beading on a cold water pipe, a window or the outside of a washing machine tells you the air is near its limit. Write down what you see, because it decides how many pints of capacity you need. Our guide to dehumidifier pints turns those readings into a size.
Stop the water first
A dehumidifier removes water from the air. It cannot keep up with a leak. The EPA lists the steps that lower humidity at the source: vent the clothes dryer and other appliances that produce moisture to the outside, and dry any water-damaged area within 24 to 48 hours of a leak or a spill. Dried within that window, the guide says, most damp materials will not grow mold.
So check the gutters, the downspouts and the grading around the house, and fix a dripping pipe before you buy anything. Then run the dehumidifier to bring the air back into range and keep it there.
Setting a Shinco dehumidifier
Every Shinco home and large-space dehumidifier sets humidity from 30 to 80 percent, most of them in 5 percent steps. For a basement, set 45 or 50 and switch to Auto: the unit runs until the room drops below your setting and starts again when it rises above it. On the SDZ1 units the band is 5 percent either way, so a setting of 50 holds the room between about 45 and 55.
Continuous mode ignores the setting and runs flat out. It is the right choice for drying a flooded corner or a load of laundry hung indoors, and the wrong one for everyday use.
| Unit | Humidity setting | Bucket | Drain |
|---|---|---|---|
| SDL-30P Compact Dehumidifier | 30–80% | 0.33 gal | Gravity hose |
| SDO-80P 86-Pint Dehumidifier | 30–80% in 5% steps | 1.06 gal | Gravity hose |
| SDX1-86P 86-Pint Dehumidifier | 30–80% in 5% steps | 1.06 gal | Gravity hose |
| SDZ1-80P Wi-Fi Dehumidifier | 30–80% in 5% steps | 1.32 gal | Gravity hose |
| SDZ1-120P Wi-Fi Dehumidifier | 30–80% in 5% steps | 1.32 gal | Gravity hose |
| SDZ1-150P Dehumidifier with Pump | 30–80% in 5% steps | 1.85 gal | Gravity hose, built-in pump |
| SGH-200P Commercial Dehumidifier | 30–80% in 5% steps | None (pump) | Hose, built-in pump |
Which unit for which basement
Start from the size of the space and how damp the meter says it is. For a bathroom, a closet or a small bedroom, the compact SDL-30P is rated for spaces up to 1,500 square feet and holds a third of a gallon in its bucket. A finished basement or a large family room is the work of the SDZ1-80P or the SDZ1-120P, rated for 5,000 and 6,000 square feet. Both connect over Wi-Fi, so you can check on a basement you rarely walk down to.
Where the floor drain sits higher than the unit, or there is no drain at all, the SDZ1-150P pushes water up and out with its pump and covers up to 7,000 square feet. Crawl spaces, garages and job sites take the SGH-200P, with a metal shell, a built-in pump and a rating of up to 8,000 square feet.
A week later: is the setting holding?
Leave the meter where it was and read it again after a week in Auto. If the room holds near your setting and the cold pipes stay dry, the unit is doing its job, and you can leave it to run through the season. If it runs without stopping and never reaches the setting, either the space needs more capacity or water is still getting in somewhere, and the gutters and the grading are the first places to look.
Where the water goes
A basement unit that removes dozens of pints a day fills a one-gallon bucket within a day. ENERGY STAR notes that many dehumidifiers take a hose that you can lead to a floor drain or a sump pump, so you never empty a bucket. Every Shinco home unit takes one, and the SDZ1-150P and SGH-200P add a built-in pump for basements where the drain sits higher than the floor.
Set the unit near the drain, off the floor if you can, with a little space around the intake and the outlet. Then leave it: a dehumidifier does its best work running in Auto through the whole damp season, not switched on for an afternoon when the smell gets bad.
Cold basements in spring and fall
Basements are coolest exactly when they are dampest, in spring and fall. ENERGY STAR warns that frost can form on the coils below 65°F, which stops the unit removing water. Keep it in the warmest part of the basement, away from an open window, and look at the coils in the first cold week. The commercial SGH-200P has auto defrost for crawl spaces that stay cold, and keeps removing water while it clears the ice.
Every unit on our basement dehumidifier page is rated for at least 5,000 square feet, with a hose option on each.
Every unit named here is part of the Shinco collection.
