HVAC Hacks: Tips for Novices and New Homeowners

Ventilation Issues In A Commercial HVAC System And How To Find/Fix Them

Commercial HVAC systems cover thousands of feet of ventilation. The ventilation starts in the basement or on the ground floor and initially travels the whole distance in the basement to the ventilation that eventually ascends to the next floors. Forced air heating and cooling systems have to make it all the way through the ventilation to the top floor, which is a monumental feat as it is.

When you have ventilation issues along the way, the higher-up floors do not receive the heat and/or air conditioning they need. Here are some common ventilation problems, how to find them, and how your HVAC repair technician fixes them.


The biggest and most common issue are leaks. Ventilation that is not fully sealed all the way up to the top floor is going to leak a lot of heat and/or air conditioning. The leaks could be really minor, but if you have a lot of minor leaks, they add up.

You can find leaks near the furnace or heating appliance(s) by running your hand along and around the welded seams of the ventilation shafts when the furnace or central air are running. When you find these leaks, mark them with a permanent marker (preferably red, to indicate a problem spot). Your technician will double check what you have found, and re-weld these areas. Then he/she will check all the shafts you cannot see or feel and fix those in the same way.

Completely Disengaged Pieces of Ventilation Shaft

This is rather an unusual problem, but it does happen. Sections of ventilation shaft will disengage from the rest of the shafts as they run vertically upward. This stops the heat or A/C from going any higher than where the break is. The repair technician will find the break by running an articulating camera into the shafts to see where the break occurred. Then he/she has to open a wall (if applicable) near the break to rejoin the shaft pieces to each other. 

Flooded Shafts

Shafts flooded with water typically occur on the first or second floor, or basement, of a building. When the shafts are flooded this low to the ground, nothing above ground is going to be a comfortable temperature. (Generally, you and all other tenants or employees are not likely to be in the building when this happens.) The water has to recede, or the HVAC technician has to pump it out before repairing any shafts that have taken on water.

For more information, contact a company like J. P. Griffin Inc.