Q. We have a spacious old home with two stories and an attic. Because the inside humidity is high in the summer, we close the house during the day and turn on the furnace fan to circulate the cool basement air. At night we open up the house, yet the humidity persists. The air conditioner dehumidifies the air, but that is expensive. Also, can you give an idea on the cost of running the furnace fan? K. Daniel Overton Remington, Ind.
A. Taking the last question first, a one-third-horsepower furnace blower running 10 hours might use 25 to 35 cents of electrical energy, depending on the cost per kilowatt hour in your area.
Your program of circulating the basement air throughout the residence during the daytime and opening up the house at night sounds very practical to me. Naturally, covering the windows either inside or out during the daylight hours will reduce heat gain from the outside.
Insulation in the ceiling and exterior walls is also a way to reduce heat gain in the summer as well as heat loss in winter.
The humidity problem may be at least reduced through the use of dehumidifiers , either in the form of individual room units or through a central dehumidifier joined to the furnace, either separate from the air conditioner or a part of it.
Check with a local air-conditioning firm for a recommendation based on your specific apparatus.
You may find that selected use of the air conditioner will reduce the interior humidity enough to make the inside atmosphere more comfortable to you.