Whole-house fans a sub for A/C
Q. I have a whole-house fan in my attic floor, but need to know more about it before using it. Can I save energy with it and how do I get maximum cooling?
Also, the attic has blown-in insulation and I wonder if the insulation will be disturbed. The attic side of the fan is boxed in with foam-insulation walls three feet high. The house is a two-story colonial.
A. Judging from your message, the fan is correctly located in the upstairs hall ceiling. These fans work by drawing in cool night air through partially open windows and expelling warm indoor air through vents in the attic.
They should not be confused with so-called attic fans, which are intended to cool attics only, not whole houses.
A whole-house fan is a substitute for air conditioning and should never be used at the same time as an air conditioner. They work best in climates where nighttime temperatures are often 72 degrees or less.
Most owners close windows during the day, when temperatures rise, and draw drapes or blinds to help contain the cooled air as long as possible.
It’s difficult to say which windows should be opened to admit the cool air while the fan is operating. Some experimenting is usually required to get the best results.
If the main objective is to cool upstairs bedrooms, then the best bet would be to open upstairs windows six to 12 inches and let upstairs doors open to provide good air circulation.
Keep in mind that it can be risky to leave downstairs windows open in some areas. Some windows can be locked in partially open positions and there are other ways to prevent a partially open windows from being opened fully; unfortunately, there isn’t space to discuss that issue here.
The deep box around your fan should keep it from disturbing your loose-fill or blown-in insulation, assuming there are enough attic vents to provide outlets for the pumped in air. I know of several cases where whole-house fans were used without problems in attics with loose-fill insulation.
If this is a two-speed fan, as many are, try it on the lowest speed first and check the attic after a few days to see if any insulation was disturbed. If not, try the higher speed to get best cooling.
If insulation is disturbed, the attic probably needs more vent space. Loose-fill insulation can also be held in place by stapling plastic screening over it. The screen used to protect fruit trees from birds should work well; it is available at garden-supply outlets.
Q. We have a 31-year-old toilet that works fine except for two tiny pinholes in the tank that leak water onto the floor. How can I repair the leak?
A. If these are just pinholes, the leak can be repaired. But even pinholes indicate that the tank is deteriorating and corroded.
The best bet, by far, is to replace the toilet. If the tank ruptures, it can cause extensive water damage to your house. You are also wasting a great deal of water with this old toilet, which could use up to five gallons per flush.
If you must repair, buy some plumber’s epoxy putty. It often looks like an oversized Tootsie Roll.
Turn off the water to the toilet and flush it, then bail out and mop out the rest of the water in the tank. Let the tank dry thoroughly, or use a heat gun or hair dryer to speed drying.
When the tank is dry, cut off a hunk of the putty and knead it until it is a uniform color, then press it over the pinhole area. Let the putty harden completely before running water into the tank.