Why Your Air Handler Should Soak Up The UV Light This Summer

Make Air Conditioning More Efficient with UV-C

Summer is finally here. Three months of warm, sunny days, ice cold beverages and microbial proliferation await you.

That’s right. One negative side effect of the warm weather is humidity. As you know, HVAC systems perform their “cooling” operation by removing heat and moisture from the air. When humidity levels are excessive, they need to work a lot harder.

Because warm air retains more water, and moisture is the lifeblood of mold and bacteria, the summer season presents a particular challenge for facility managers. Mold, viruses, spores and bacteria can go dormant during periods of low humidity and spring back to life and flourish once moisture is introduced.

For one, cooling becomes far less efficient (as the ability of a coil to remove heat is reduced), and facility managers will often get complaints from building occupants about it being hot or uncomfortable. Complaints encourage an immediate response from HVAC engineers, who often increase fan speed or lower chilled water temperatures to compensate, which of course puts a strain on the system and causes the monthly energy bill to skyrocket.

What’s more, cooling coils not only cool the air, but also dehumidify it. Therefore, a fouled coil will make it both hotter and more humid inside, which compounds discomfort even more. Hot and sticky occupants continue complaining, and the fan speed keeps getting raised.

It’s a vicious cycle, and the only long-term, cost-effective solution is ultraviolet-C (UV-C) irradiation.

UV-C Keeps it Cool

Installed in an existing system, UV-C reverses the cycle by inactivating and destroying the microbial buildup 24/7/365. Pressure drop decreases, air moves more efficiently through the coil and fan speeds can be reduced. Occupants stay cool and dry, while owners see reductions of up to 25 percent on their monthly energy bill.

And this solution doesn’t break the bank. In fact, quite the opposite. UV-C lamps from UV Resources are among the most affordable on the market. Using a 10,000 cfm system as an example, the installed UV-C fixtures would cost $1,500, with an annual operating cost of $188 at $0.10/kW – operating around the clock. That is less than one percent of the average power savings gained through a more efficient (better heat transfer and lower pressure drop) air conditioning system.

Furthermore, field reports indicate that the initial cost of a UV-C system is about the same as one properly performed coil-cleaning procedure, and less when system shutdowns, off-hours work with the associated overtime, and/or contractor labor costs, are considered. Chemical or mechanical coil cleanings are also temporary. UV-C is a permanent solution as long as the lamps are replaced once per year. Taking this into account, it might be more rational to make a one-time investment in a UV-C system that will keep cooling coils at as-built conditions.