Along with reducing energy costs it is important to keep in mind the health of you and your household.
Do not compromise your health for immediate money savings.
Here are some basic tips to control the quality of your home's indoor air and protect your household from many airborne irritants and/or health problems:

• Seal up any air leaks.
• Keep your home dry (indoor relative humidity below 70%—ideally between 45% and 60%.
• Keep your home clean and free from bugs and excessive dust.
• If you use pesticides, do so only as directed in the instructions on the product labels. When building new or conducting home improvement projects, choose products that have no or little potential health impact (e.g., little to no off-gassing of VOCs [volatile organic compounds], no formaldehyde, etc.)
• Replace your heating and cooling filters regularly with good quality single-use filters designed for your system. If you have additional concerns about specific allergens, consult with your air conditioning contractor about filtration options more appropriate to your situation.
• Use biodegradable cleaning supplies that do not off-gas.
• If you have an attached garage or a fuel-fired appliance, heater or fireplace, install carbon monoxide alarms as recommended by the EPA or the manufacturer. (“Fuel-fired” means a device that uses kerosene, propane, oil, natural gas, or wood.)
• Do not allow smoking inside your home.
• Install smoke alarms.

Source: Energy Efficient Homes: Indoor Air Quality and Energy1Hyun-Jeong Lee, Kathleen Ruppert, Wendell Porter, UF IFAS FCS3275, 2008

Additional Resources

EnergyStar®  - http://www.energystar.gov/

UF IFAS Energy Efficient Homes: Indoor Air Quality and Energy http://edis.ifas.ufl.edu/FY1044