Hello! I make my living with air quality and comfort, and had a wife with severe allergies at one point, but no longer. I have done a lot of research, trial and error out the ying yang, and a lot of items that were not so good, but still expensive. I have learned a lot about allergies and air quality in the process. There will be some that will disagree with me, but thats O.K., this is what has worked for me and many more. The Honeywell FC40R Return Grill Media Air Cleaner, big word for Filter, will fit right in your return air grill, around $45.00. Electrostatics need attention and maintenance. Make sure your Returns and Duct work is not leaking and that the Evaporator coil is cleaned. The go check out 2 products, RCI technology by Ecoquest called Duct WoRX and RGF Environmental Group who makes the Guardian Air. Both products work great, RCI is a multilevel setup and RGF's the Guardian Air is the one I prefered do to its 360 radius in the air stream, around $450.00. Do some research on these to products and if you have questions as they say here in Tennessee "Holler Back at me"

I have had in several homes for over 30 years an Electrostatic filters with a standard filter in front of it. This reduces the dusting requirements dramatically or so says my wife.

Allergies are hard to address if you don't know what your daughter is allergic to. Could be pet hair, pet dander, dust, pollen, smoke, mold, chemical cleaners, off gassing (VOCs) or other causes.

UV lights can kill bacteria, mold and fungi which either pass by the light or which the light shines on. In fact I've seen a test on a cooling coil, black with mold and one month later was clean and void of all mold. In fact it only takes 20 minutes per month for a UV light to kill & eliminate bacteria, mold & fungi on coiling coils & drain pans. A two bulb unit placed directly above the "A" coil is recommended, a single bulb unit will cast shadows and be less effective.

In addition, a 5" pleated filter with a high MERV rating (Minimum Efficency Rating Value) to address dust, hair, dander & pollen should do the trick. Always consult your contractor to see if this is possible, due to the increased restriction of airflow.

VOC's can come from carpet glues, adhesives, paint, partical board and other such items. Eliminating carpets which trap and hold pollutants is another step. Incorporating wood, tile or laminate floors which are easier to keep clean is a good alternative to carpeting.

If your daughter has been tested to know what she could be allergic to, the direct cause could be addressed more economically.

Hope it helps,

Dan Martyn

The key to good indoor air quality is to leave the bad air outside. I would suggest that you have someone perform a blower door & duct test on your house (maybe $250-400) and determine the air infiltration rate and duct leakage. If these are high then sealing would be in order. Money spent on sealing your house and duct work to keep the polluted air outside is the first order of business. After that you can consider additional measures. Water is the biggest pollutant indoors and that comes form showering and cooking mostly. Good exhaust vents in the bathroom (no condensation on the mirrors) and kitchen are important. Checkout the Energy Star website - you can download a DIY guide and find lots of brochures about indoor air quality, duct sealing and home sealing.

Considering all of the additional pollutant sources and the accumulation factor, typically indoor air is more polluted than the outdoor air. In fact EPA studies have found indoor VOC levels that were 2 to 5 times higher than outdoors. See the link reference.

Dan Martyn

Here is a link that might be useful: Indoor Air Quality