Q: "We just bought a new retirement home in Arizona. Instead of the usual furnace filter system we had up north, this HVAC system has one very large cold return air grille high on the wall in the family room. Up north there were lots of cold air returns but none had a place for a filter and none were this large. We understand this is the new way of filtering air. The grille tips out and holds a one inch filter panel. We want to avoid any unnecessary house cleaning. Which cold air system do you recommend and why? Thanks. Pete."
Answer: Particularly in Southern and Western states where air conditioning is used most of the year, the newer homes have filter slots in return air grilles. One website notes that furnace filters located in the furnace plenum near the motor are meant to keep the motor clean, not the household air. The less dirt that gets to the motor, the more likely you'll get longer life. The problem is that dust and dirt get into the duct work. So filter grills not only keep the household air cleaner but also keep your duct work cleaner. Modifying older HVAC systems is difficult because the actual ductwork is often much smaller. If you put too high of a MERV rated filter into the furnace slot, you'll cut down the air movement and possibly have an overheated motor,too.
Safe Home™ sells the Safe Home Duo and the Safe Home System. Both are disposable filter products which means no messy washing, waiting for filters to dry and most likely running the unit without any filtration during that time.
The Duo has an internal metal frame with two filters, one for dust, mold, dirt and pollen and the other for gasses such as formaldehyde. The unit fits very tightly into the tip out filter grille holder because the filtration media surrounds the metal frame. The second layer, the inner layer, is impregnated with carbon and potassium permanganate which capture the VOC's such as formaldehyde and ammonia. We suggest changing that filter about every 3 months unless your home is subject to dust from remodeling, etc.
The second, the Safe Home System, consists of 5 filters of which 4 are electrostatic. These are pleated with wires that create the static charge. These 4 pre-filters that capture dust, pollen, dirt, etc. fit into the grille itself. The 5th filter, the VOC or volatile organic chemical filter, actually fits into the duct opening behind the grille. So it fits into the actual duct work. The System has 125 grams per square foot of activated carbon and FormadaSorb to remove the most common, hazardous pollutants. The replacement filters for the filter slot are electrostatic air purifier filters. These pre-filters should be changed at least every three months.
NOTE: Neither of these filters will remove carbon monoxide, radon gas or carbon dioxide. We recommend installing carbon monoxide monitors on every level of your home and in or near all sleeping areas. Test units regularly. Replace batteries at least annually.
So, either unit will meet your needs. Do check and make sure the carbon chemical fits. The Safe Home Duo and the Safe Home Filter System come in sizes to fit almost everyone's return air grille and/or furnace slot. If you have custom sized slots, please contact us for pricing on special sizes.
Thanks for your question.