Inman

Ventilation fix for old house

Q: My 900-square-foot 1920s stucco home faces directly west and it gets unbearable during our mercifully brief heat waves. It’s been suggested that an exhaust fan of some sort would help. I have 9-foot ceilings but only 2 feet or so of attic space running under a flat, poured-surface roof. The heat penetrates even to the inside walls and builds over days. I have fair cross-ventilation to all but the bedroom, which I must find a way to cool.

I see various fans in the stores. Would you give me some advice on their effectiveness and noise level? There’s a roof-mounted type, an exterior wall unit and one that can be mounted within a vent tube from the bedroom ceiling to an exterior wall. I don’t like the sounds fans make.

Do fans — and their noise — help enough to make the expense worthwhile? Would increasing the number of attic vents also help or be required for the fan? I shade the west side with an awning and have insulated windows. There is no insulation in the walls. Insulation in the attic is not feasible because the clearance is so low and I’ve been told not to cover the old electric wiring system.

A: As you have discovered, stucco siding and sparse attic space are great in the winter. They hold heat like a champ. But come summertime, it’s a different story.

Your 9-foot ceilings help some — more space, more places for the heat to go. But we think you should consider making a few, relatively inexpensive improvements to help you cool off a bit.

The goal here is to reduce the bedroom temperature to approximately that of the outside.

Your first line of attack should be to get the heat out of the attic. Check out the current ventilation situation. Often in this style of home, attic ventilation was provided with a few terra cotta pipes protruding from the attic through the stucco.

You often see them above the garage door or close to the ridgeline of the roof. This is aesthetically pleasing, but if it’s the only source of attic ventilation it’s not enough.

Install a couple of turbine-style fans to vent the hot air. This is a passive system requiring no motors — and no motor noise. Hot air rises, so the warm attic air flows through the turbines and vents to the outside. The faster the turbine spins, the more hot air is drawn out.

Another option to vent attic air is a thermostatically controlled attic fan. A thermostat activates a motorized fan to vent attic air outside at a predetermined temperature. Because the fan is in the attic, noise will be minimal. Some minor electrical work will have to be done during installation.

The second thing we would do is install a ceiling fan in the bedroom. Again, because hot air rises it tends to collect near the ceiling. A fan moves and mixes the air, making for a more consistent temperature at various elevations in the room. The breeze generated also has a cooling effect. Fans are incredibly quiet. The only noise is not from the motor but from the fan blades moving the air.

The final thing to consider is to blow insulation into the stucco walls. That will reduce the transfer of heat into the house during the summer and out of the house during the winter.

Given your dislike for noise, avoid the exhaust fan vented from your bedroom to the outside. The noise would be too great.

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