A box fan in the hallway is not a dry-out. It is a breeze. You want evaporation off the slab and the open wall, then a machine that wrings that moisture out of the air.
How many depends on cubic feet and how wet it is. A small bedroom can need one serious dehumidifier and a couple of air movers. A whole first floor needs a plan, not a Target run.
Close off dry rooms so you are not dehumidifying the neighborhood.
Do this now
- Measure the wet area roughly. More cubic feet means more dehumidifier capacity, not more random fans.
- Point air movers along the floor at wet walls, not straight up at the ceiling.
- Put the dehumidifier in the wet zone with doors to dry rooms closed.
- Drain the dehumidifier into a sink or a hose, not back onto the slab.
Aiming the air
Air movers should skim the wet surface. A 5-to-15-degree tilt along the floor is the usual picture. Stacking three fans in a pyramid in the middle of the room is a photo, not a method.
Keep them a couple of feet off the wall so air can actually turn. Watch cords. Wet slab plus cheap power strips is how you add an electrical problem.
If a room still smells like a swamp after a day, you are missing a wet cavity or you do not have enough dehumidification.
Houston-specific limits
Outdoor air is often so wet that ‘open the house and hope’ backfires. If you have dehumidifiers, use them and limit the open windows.
If you have no power, you cannot fake this with prayer. Get to a dry place and rent machines when the grid is back, or hire a crew with generators.
Write down grain depression or at least the humidity reading twice a day if the machine shows it. Numbers keep you honest when your skin lies.
Do this next
- First 24 hours: pull water, move stuff, start airflow
- Shop vacs, pumps, and what to borrow from a neighbor
- Water cleanup hub
More in Getting water out & drying now.