Humidity check
What a humidity check measures, and in what order.
A damp house isn't one problem. The check tells apart a house that holds too much water in the air, a system that doesn't remove it and a floor that lets it in.
What to measure first
Seven readings, in this order.
The first five take an afternoon and 48 hours of logging. The last two happen only if the first five point there.
Room humidity and temperature
A logger sits in the room that bothers you for 48 hours. One reading tells you little: Charleston air swings from a cool, dry morning to a wet afternoon.
The dew point
From those two numbers we work out the dew point, the temperature at which air starts leaving water on a surface. Anything colder than it will sweat.
Surface temperatures
Windows, supply registers, a duct run, an outside wall. We compare each one to the dew point to see what is sweating, and why.
How long the air conditioner runs
A cooling cycle that ends in a few minutes cools the air without drying it. We time the cycles on a warm afternoon.
What is under the floor
On a raised house we read the crawlspace the same way. Damp air under the floor moves up into the rooms.
Air from the supply registers
If the air leaving a vent is only a few degrees colder than the air going in, the coil isn't pulling much water out.
Where the moisture comes in
Dryer vents, bath fans, a door that doesn't seal, gutters that empty at the foundation. We walk the outside as well.
Signs
What a damp house looks like.
None of these proves a humidity problem alone. Together they are a reason to measure.
Windows and supply registers that sweat
Water on the inside of the glass or beads on a vent.
A musty smell
Strongest in a closet, a bathroom or when the system starts.
Sticky floors and furniture
A house at 74 degrees that still feels damp.
Doors and cabinets that swell
Doors that rub in August and don't in January.
Cupping floors or a damp crawlspace
Boards that curl at the edges, or a dank smell from the vents.
An air conditioner that runs in short cycles
On for a few minutes, off, on again.
The visit
What happens, start to finish.
Plan on about two hours at the house, and a second short visit to collect the loggers.
- 01
Step 1: We arrive and walk the house
You show us the rooms and the times it is worst.
- 02
Step 2: We place the loggers
One in the worst room, one beside the thermostat and one in the crawlspace or attic if there is one.
- 03
Step 3: We time a cooling cycle
On a warm afternoon, with the doors closed.
- 04
Step 4: We collect the loggers 48 hours later
And read the numbers with you.
- 05
Step 5: You get the readings in writing
A one-page summary, then a written scope if you want one. The scope arrives before any work.
Cost
What moves the price of fixing it.
No dollars on this page. These are the things the written scope will itemize.
The equipment fits the house
A ducted unit needs ducts it can tie into; a crawlspace unit needs a closed crawlspace.
The size of the space
Set from the readings and the volume of the house.
Access
Attic, crawlspace height and a second-floor air handler change the time.
Drain and power
A condensate line, a new circuit or a pump.
Work to do first
Sealed vents, a ground cover, a failed duct joint.
Questions
Before the first reading.
What humidity should my house be?
The EPA suggests keeping indoor relative humidity below 60 percent, and ideally between 30 and 50 percent. A Charleston house that sits above that for days at a time is worth measuring.
What is a dew point, and why do you start there?
It is the temperature at which the air in a room begins leaving water on a surface. A window, a duct or a cold wall that is colder than the dew point will sweat. Knowing it tells us which surfaces to look at and how much drying the house needs.
Does a dehumidifier remove mold?
No. It lowers humidity so conditions are less friendly to mold, but it doesn't remove mold that is already growing. If you can see mold, ask a mold professional to look at it; we are not mold remediators.
What does the first visit cost?
The visit fee is quoted when you book, in writing. If you hire us for equipment, the fee is credited toward the work. See how pricing works for what a written scope contains.
Start with a reading.
Book the humidity check, and we'll put the loggers where the house is worst.