Advice on ventilating a room needed

[Eireann]

As some of you know, I currently live in a converted garage. Well, the bedroom is a converted garage. And there's no basement underneath, so it sits right on the ground and gives me all the coldness in the winter, and it's dark (only one window, with the trees outside blocking much of the light).

So recently, when I was using the slow cooker to make truly gorgeous chili, the moisture gathered in the bedroom and created an enormous crop of mildew on one wall. I brushed vinegar all over it, and I haven't used the slow cooker since.

The day before yesterday, I did a load of laundry. I don't have a dryer (they still aren't common here), so I put it on a drying rack. It's below freezing, so I have the drying rack inside.

I came home today and found that the mildew had returned with a vengeance. It seems that the only way to prevent it in situations like this is to keep the dehumidifier running constantly.

So I asked my landlord about inserting a ventilation grid in the wall. One of the bedroom walls would be perfect for a said grid. My landlord came in, looked at the mildewy area (the vinegar left a mark), and agreed that a grid could be put in there, and suggested putting it at the top of the wall.

While I know none of you know what the inside of this house looks like, can you give me any advice on putting a grid in a wall? I imagine he'll work it out; I'd just like to know for myself.

[Kittish]

I've no experience and I'm sure pretty much all of what I have comes under common sense.

Before cutting big holes in the wall, make sure there are no wall studs, water pipes, or electrical conduits in the area you're looking at removing to install the ventilation grid.

Frame it in properly, otherwise it's liable to cause further issues down the line.

Check inside the walls while there's a handy hole to see if there is mold or mildew inside the walls.

That's about all I have I think. Take it for what it's worth.

[wolfie]

By "ventilation grid", I assume you mean an opening with louvers to keep wildlife out. If so, a grid on its own isn't going to do much. You'd be better off with an exhaust fan (commonly found in bathrooms and kitchens). Not only will it force airflow, but it will force it in the right direction (you DON'T want cold air coming IN where you've got a moisture problem - it'll just condense more moisture out of the air). Ductwork for an exhaust fan should either go horizontally, or down from the intake ("landlocked" bathroom, duct goes down through a wall cavity and then out via a duct in the floor joist space) - never up (i.e. through the roof), or you'll get condensation forming in the duct and dripping into the room. In your case, it would be a simple horizontal run through the wall.

The best (unfortunately most expensive initially, but saves money in the long run) solution is a heat recovery ventilator. This is a 2-way vent (dumps old air and brings in new) with a heat exchanger - as the old air is on its way out, it warms the new air coming in. If you just have an exhaust fan, the replacement air will find its own way in through leaks - but you'll be dumping warm air and bringing in cold replacement air, so the heating system will need to work harder.

What sort of heating system do you have? Is it forced air, or something like baseboard units? If forced air, the best place for the heat recovery ventilator is in the return air stream - dump "not quite room temperature" air, and the partially heated replacement air goes through the furnace (and gets fully warmed) before going into the room.

[Eireann]

The house is brick, built sometime in the 1930s. I think my landlord is going to discuss the vent idea with others; although he agreed to do it, he wasn't ready to get it done right away. Wolfie, thanks so much for your information! Given the solidity of the wall, I really don't know how a duct will be installed. This ventilation grid will be in an interior wall, so providing air flow between my apartment and the (colder) hallway). There is a fan in the bathroom, and it's set into the wall, but I have no idea where the duct goes. That was a good idea on someone's part.

I've already decided to move when my lease ends at the beginning of March. That place makes a good garage, but a terrible apartment. Cold, insufficient ventilation, sitting right on the ground... yeah, they didn't think that one out when they converted it. Or if they did, they just chose the cheapest route. I get mildew from using my slow cooker; I get mildew from hanging my laundry to dry indoors. The plaster is weak and cracked in several areas, and that's just how it will be from here on out, unless they undertake a major renovation project. I think they're far more likely to keep renting it one year at a time, to a string of tenants.

As for the heat, it's provided by electric heaters (forced air would be fantastic, I think, but I don't have it). There's also a heating pipe going through the kitchen/living room that connects the apartment below mine to my landlord's apartment above. When the heat is on in the house, it provides warmth.

[wolfie]

A vent on an INSIDE wall? That's just going to spread the moisture (and resulting mildew) to other rooms. Since the brick wall is the outside wall, there's no need to run a vent down it (as I said before, that's what you'd do for a "landlocked" bathroom). A vent from an exhaust fan can go through the wall.

[Eireann]

Yes, an inside wall - but the other side is the hallway, with much better air circulation. Does that make a difference?

[TheSHAD0W]

Yeah, I'd say you need active ventilation, not just a louvered vent. They make fans designed to mount on top of those vents, which would fit the bill, depending on the size. Your apartment has no window?

[Eireann]

There are two windows, one in each room (the bathroom is off the kitchen/living room, and is windowless). The bedroom, which used to be the garage, has three trees growing outside, and they block a lot of light. Plus, ironically, the windows are new, so they don't leak air. I think if they did, the circulation would be better.

I'll give you more details. The house has flat roofs, and the garage has no rooms above it. This flat roof has a drainage pipe running from one corner, down the wall (in other words, just on the other side of my bedroom wall) and to the ground. In front, there's a drainage duct. So not only is the garage sitting directly on the ground, but rainwater drains directly into said ground. I think it would take a LOT of construction work to make it a good place to live - better ventilation, directing all rainwater well away from the house, etc.

[TheSHAD0W]

A window fan unit would probably work for you, depending on outside temperature and whether your heating can keep up.