Show us your air handler, and we’ll show you how to make it less mold-friendly

Central air conditioning has been the norm of American home environmental control for many decades now, and there are lots of manufacturers and configurations of “air handlers” available.  The air handler is like the “heart” of your central AC system, because it contains the fan that “pumps” air all around your home.  If you live in a humid climate, or if you get a whiff of “musty” smell but can’t find any mold in your home, it's important to open up this unit and make sure you don’t have a mold factory going on.  If you do find mold, check out one of our articles on cleaning it up, and come to us for specialized advice on installing a BP-2400 for maximum mold protection of your expensive system.  First, let’s look at the important parts of air handlers:

Source: Detecting Human Movement by Differential Air Pressure Sensing in HVAC System Ductwork: An Exploration in Infrastructure Mediated Sensing

“Return Air” is where air is drawn into the air handler unit, from one or more grilles in the home.  The Air Filter may be located in those grilles (in this case 2 separate streams are shown), or may be located in this first part of the air handler. You don’t want to have air filters in the grilles AND the slot before the air handler, because that would cause too much pressure drop on the unit. 

The Fan is usually a “blower” type fan, which draws air into its center and uses blades on a cylindrical cage-type rotor to push it out one side (also called a “squirrel cage blower” because it looks like a hamster or squirrel wheel!).  The Cooling Coils are a heat exchanger where coolant flows inside the coils, while the air flows over the coils, and heat is removed from the air and transferred to the coolant.  The Heater/Furnace is either electric coils, or a gas combustion heater.  Finally, air exits the air handler and flows through ducts to individual rooms.   Here is the photo of a similar system (cooling coil and fan are in reverse order) installed in an attic with the parts labelled:

There are four spots we recommend for this install:

1. In the Return Air ductwork, a BP-2400 can be placed in the duct before the air handler, so that ions impact the filter and keep mold or microbes from growing.  

2. The BP-2400 has magnets on the body of the ion generator to easily attach to the metal housing of a fan.  If your fan housing is plastic, double-sided tape can be used.

3. Cooling coils and the drip pan are notorious for growing mold.  Placing the BP-2400 on the inlet to the cooling coils will deter mold growth.  

4. The BP-2400 can be placed downstream in the register/vent of the largest room to add ion protection there.  

Note: The BP-2400 is not rated for temperatures over 150 deg F, so it can’t be placed directly after the furnace or heating coils. 

If you’re interested in the best place(s) to install a BP-2400 in your system, contact us and include the model of air handler, sizes of the return air grille(s)/filter(s), and a photo of how the air handler is installed.   We will get back to you with the best place to install it and also a recommendation on how to improve filtration in your home by increasing MERV, if your system allows it.

Photo by Taylor Vick on Unsplash