Q. I replaced the old windows and storm windows in my house with high-efficiency thermal replacement windows. When it gets very cold, we get condensation on the new windows. We didn’t have that problem before. What’s going on?
A. Your old windows probably had enough gaps to let moisture-laden air from the house escape, but the new windows have given you a tighter house. As a result, if the relative humidity in your house is high, it causes water vapor to condense on cold surfaces (the interior panel of thermal windows can get quite cold).
Window condensation can sometimes damage walls and woodwork and foster formation of mold. And high relative humidity also can create mold problems.
You should check the relative humidity to see if it exceeds the recommended level of 40 to 45 percent. You can check it with a hygrometer or moisture meter, often sold at home centers in combination with a thermometer.
To correct high relative humidity, use ventilating fans in bathrooms, kitchen and laundry rooms and make sure your clothes dryer is properly vented to the outside.
Cases of extreme window condensation in homes with gas heat should be checked immediately. The cause here can be a blocked chimney or heater vent that can cause deadly carbon monoxide gas to accumulate in the house.
Q. I live in a townhouse that has concrete walls between units. My neighbors smoke, and I get a strong smoke odor in my unit. I suspect they are smoking in the bathroom with the intention of venting the smoke outside. How does smoke get into my unit and how can I overcome this?
A. In some multifamily housing, several bathroom vent fans can be connected to the same outside vent. If this is the case in your townhouse, the smoke could be entering your unit through the bathroom vent. Try turning your bathroom vent fan on when you smell smoke and see if there is any improvement.
However, tobacco smoke is extremely pervasive and it could be entering through various other openings or cracks, and the sources can be very difficult to locate and seal.
If you can’t convince the neighbors to stop smoking, the best bet is to install an air cleaner with a high rating for smoke removal. If you have a forced-air heating and cooling system with ducts to each room, a central air cleaner would be most effective. Less-expensive room-size units are also available, and can be used in areas where you spend the most time or where the smoke odor is the strongest.
Look for a cleaner with a HEPA (high-efficiency particulate air) filter, which can help screen out airborne particles responsible for many allergies as well as smoke. To get an overview of cleaners that should help you, use a search engine and the words Best Air Cleaners for Smoke Odor.
Q. The glass on my storm window is covered with what looks like hard-water stains. I’ve tried everything, including professional products, but nothing removes the stains. Can you help?
A. It is possible the glass has become etched by acid rain or other weather conditions in your area, which could make the glass impossible to clean thoroughly.
Before giving up, though, try gently scrubbing the stains with a cleanser such as Bon Ami or Soft Scrub on a soft, moist cloth. Very fine steel wool (4-0 grade), lubricated with soapy water, might also remove some of the stain.
It’s best to test these remedies on the edge of a stain and stop if you don’t get good results.