Adding a ventilation fan in the basement

11 years ago

I have a finished basement including a 10x10 laundry room with a washer, dryer, and water heater. The laundry room is insulated (for sound, i guess) and does not have a louvered door and gets really quite warm and somewhat muggy. the cat box and the whole room is just gross.

the air quality in the rest of the basement is okay, although my friends with cat allergies have reactions in the basement but not in the rest of the house.

i would like to add an always-on or usually-on vent to the laundry room to the outdoors. the radon fans look like they might do the trick. or a basic, very quiet and low volume bathroom type vent, perhaps that kicks on and off based on the temperature of the laundry room.

additionally, i plan to add a basic room-to-room vent (hole in the wall with a louvered cover) between the laundry room and the main living space.

my question is regarding air flow. i don't want to create a negative pressure environment in our basement, which is a main living area. we have a high-efficiency condensing furnace with a fresh air intake. the basement has two vents but no dedicated returns.

is it safe to add a powered, always-on vent to this basement?

Comments (9)

geoffrey_b
11 years ago
You can get a 'thru the wall vent' with the blower on the outside - very quiet. Add a motor speed control, and you can adjust the cfm.

I used one like this:

http://www.bathroomfanexperts.com/product.php?p=fantech_rvf4xl&product=137071

With a motor control.
Elmer J Fudd
11 years ago
Why is your laundry room muggy, that doesn't sound right. Also you say the room is gross, are you scooping out the solid waste every day? A litter box shouldn't have an overwhelming smell.

Having covered that, keep in mind that when there are pressure differences, air takes the shortest path. If you have a regular atmospheric vent stack for the water heater, air will be drawn from there to your exhaust fan. That's not something you want to have happen.

I think this room may need a fresh air vent line from outside, in addition to an exhaust fan similarly set up. Put the openings for each on opposite walls if you can.
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civ_IV_fan
Original Author
11 years ago
I don't know what the deal is with the humidity. It seems to correspond with my (oldish) water heater turning on and off.

I clean the cat box out every one or two days. My cat is old and half-senile (smelly cat stage). She misses the box pretty much every day, that is why it stinks. I'm constantly bleaching the floor in there. That is another topic though.

The laundry room is configured with one exterior wall and three interior walls. I could put a fresh air vent somewhere else in the basement but my concern would be that it would then become warm in the summer and cold in the winter.
Elmer J Fudd
11 years ago
Water vapor (humidity) is produced when gas burns. So too is carbon monoxide. I'd be concerned that maybe your combustion exhaust is being released into the room.

If I were you, I'd get an HVAC man out asap to assess the situation. A room that contains a water heater shouldn't normally be humid. Warm, perhaps, but not humid.

Yes, it will be colder and warmer with ventilation because of the inflow of outside air. But the same would be true if you don't expressly provide for ventilation, the air would be sucked in via infiltration (the gaps in the house). You don't want to be running a combustion device without adequate outside air, however you want to provide it. If you exhaust the air out of the room where it's located, it will need that much more inflow.
weedmeister
11 years ago
Is this a gas hot water heater? Is this a gas dryer? If so, there needs to be a vent somewhere. I would put one in the door or the wall. The same for combustion air, a 4"-6" vent through the outside wall.
Elmer J Fudd
11 years ago
Good catch, weedmeister, I forgot to consider that the dryer is also a source of humidity. And, if an improperly vented gas dryer, also a source of carbon monoxide.
civ_IV_fan
Original Author
11 years ago
"Is this a gas hot water heater? Is this a gas dryer? If so, there needs to be a vent somewhere. I would put one in the door or the wall. The same for combustion air, a 4"-6" vent through the outside wall."

It is a gas water heater and an electric dryer. The water heat has a vent with a positive slope heading outside.

Before I do anything, I'm going to buy a CO detector for the basement. We spend a lot of time down there. It is our TV and computer room.
ionized_gw
11 years ago
Drawing warm, humid outside air into a relatively cool basement is a sure recipe for humidity and moisture problems.
weedmeister
11 years ago
so, if the dryer is running at the same time the gas wh is fired up, which way does the exhaust from the wh travel? Up the vent stack or out into the closet and through the dryer? (assuming this is not a power-vent wh)