Topic: Some common issues with the HVAC systems

I am wondering what the most common HVAC problem the maintenance staff runs into. As an air conditioning contractor, I've installed the HVAC systems in over 35 multi-family properties. As the contractor I warranty my workmanship for one year, after that the maintenance staff takes over and most of the time I lose contact. I have often wanted to follow up with the properties.

Hey Wayne,

I am the Assistant Maintenance supervisor for a 14 year old, 268 unit apartment community as well as a former HVAC technician. At our property, the most common "no-cool" is usually (1.) clogged condensate line(water leak, float switch), (2.) Failed run cap or (3.) Ants in the contactor, pretty much in that order!

Many of our 3 and 4 bedroom units experience decreased airflow in the guest bedrooms furthest away from the air handler. I suspect because when the units were installed, the guys used all the same duct size throughout with no thought to the static pressure needed to push it that far or friction loss!

I know with the fur-down units, overflow sometimes happened because the installers secured the unit by the 4 lag bolts flush and tight to the structure. This was remedied by shimming the drain side down an 1/8 to a 1/4 inch. I definitely can see the capacitors getting a work out. They probably would start failing after 2-3 years due to high system demand and ambient temps. Do you have those thick bodied carpenter ants in your area? Around here, one stuck in the contactor is all it takes to get the staff out on a weekend night.

If all the other areas cool and heat well, then like you suggested, it could be a duct-sizing problem. On one project in particular, I had the installers relocate the takeoff for the farthest run closer towards the end of the supply plenum.

I usually get a whole clump of them. I usually replace the contactor for a covered contactor, and take the old one back to the shop and clean it! COmpany policy won't let us run no-cools after dark for safety. Love that!