According to the EPA, indoor air can be 2 to 5 times more polluted than outdoor air, in part because of the chemicals used in the construction process. Allergy and asthma sufferers know the impact on health. Clean the air by eliminating bacteria, viruses, and mold, and capture odors from cooking, chemicals, pets, or cigarette smoke. With central Heating Ventilating and Cooling (HVAC) systems, you have 'supply' and 'return' ducts plus a filter for the air conditioner and heater.
Make sure to replace the filter regularly per the specifications on the packaging, and choose a filter that specifically adds extra protection for just a few extra dollars. Consider a whole house Electrostatic air cleaner to eliminate mold and pollen. The ROI Calculation is based on the offset of annualizing the cost of $250 room purifiers for four rooms over ten years, plus the health savings. If just one household member needs to go to the doctor each year, the co-pay may be $25, or if you had to buy any respiratory medicine you'll save. Long term health is not even factored into the savings.
Good to Know:
Home and Family Safety Precautions - such as Carbon Monoxide Detectors, Smoke Detectors, 2nd Floor Emergency Ladders, Emergency Planning, Emergency Survival Kit with adequate water, non-perishable food, back-up generator, etc may be important for some homeowners. The payback on a correctly implemented program may hopefully never need to come so the return is truly a placeholder to factor in offset costs during a possible crisis within a decade. Family health and safety is simply priceless, so stay prepared. Note that Carbon Monoxide Detectors typically need to be replaced about every three years. So you should write on the outside with a marker "Replace in 2012, etc."
If you are considering replacing your water heater with an on demand heater, or if
you already have one, you may want to look
into additional Carbon Monoxide detection
to check the air quality and protect yourself and your family.