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Poor Air Flow From Your AC? Check for Duct Problems


poor air flow from duct problems

Especially in a commercial space where windows don’t open, it’s essential to have properly functioning ventilation. One of the most common sources of HVAC air flow issues is air duct problems.

Stuffy, stagnant air is difficult to put up with. When air conditioning problems lead to insufficient air flow in your workplace, you’ll notice people taking every opportunity to get out of there. Going outside for a break, taking long lunches… maybe you’ve done it yourself. If so, it’s time to get to the root of the problem before lagging productivity begins to impact your bottom line.

But before we dig into that, let’s first identify the signs of air flow problems.

Symptoms of poor HVAC air flow caused by duct problems

Stuffy air

When your space begins to feel stuffy and stale day after day, at first you may not be aware that your HVAC system is to blame.

That can happen in the spring, before the arrival of summer heat that instantly alerts you when your AC is having problems. But in moderate temperatures, the first sign of duct problems may be that feeling that air isn’t moving through your space.

Lack of air coming from the AC registers

Even though you hear the air conditioning running, you may notice that very little air is coming out of your registers. When that happens, there’s a very good chance that you have duct problems such as clogs, leaks or poor ductwork design.

Temperature variance

When air doesn’t move through your space as designed due to HVAC duct problems, you’ll notice temperature inconsistencies as well as poor air flow. You may have some areas with reduced air flow and temperatures that are too warm, and others where it’s drafty and too cold.

Unbalanced air pressure

When your ventilation isn’t working as designed, you can and up with unbalanced air pressure. Duct problems can cause symptoms like doors that slam by themselves, odors that linger or migrate, or strange whistling noises. You may be starting to wonder if your space is haunted!

Related article: HVAC Troubleshooting: Surprising Symptoms of HVAC Problems

4 duct problems that reduce air flow and your comfort

Blocked registers

This is a very common situation in a commercial setting, and one problem you can fix yourself.

Your air ducts can’t properly distribute air throughout your space when vents and registers are closed or blocked. That can happen by accident when furniture is rearranged and no one pays attention to where the vents are located. But more often employees take matters into their own hands when they are too hot or cold, and close the vents or intentionally block them with furniture.

Related article: Office Air Conditioning Battles: Take Control Before Workers Do

Clogged ductwork

Especially when HVAC maintenance has been neglected, dust and debris can accumulate in the ductwork. Over time, air flow is reduced and can eventually become completely blocked. When one duct run is blocked, you may experience those temperature variance symptoms in different parts of your space.

If dirty ductwork is causing your air flow problems, investing in duct cleaning service can be a quick and easy solution.

To learn more about duct cleaning and how it affects your HVAC system and air quality, read this helpful guide: FAQ: HVAC Duct Cleaning & Indoor Air Quality.

Refrigeration Preventative Maintenance Contracts

Air leaks

Leaks, cracks and holes in your ductwork mean that the cooled air coming from your air conditioner never makes it to the space that needs cooling. Duct problems caused by leaks can happen for many reasons: age, poor installation practices and even nesting rodents.

Improper sealing of duct joints is one culprit: did you know that you can lose as much as 20 percent of conditioned air this way? High-efficiency systems that run longer at a lower capacity are especially prone to this problem. Ducts should be sealed with mastic gum or metal-backed tape to prevent leaks.

Sagging joints is another problem caused by improper installation. It’s tempting for installers to take shortcuts, especially in NYC commercial spaces where equipment and ductwork tends to be jammed into any available crawl space. Make sure your ductwork is properly supported to prevent leaks and duct problems.

Poor ductwork design

There are a couple of reasons you could end up with a poor ductwork design that impedes the function of your HVAC system.

  1. Your space may have been renovated without updating your HVAC system. Even if you just changed the layout of your space–rearranged cubicles and office areas–your ductwork may no longer be moving conditioned air to where you need it.
  2. Or, you may have ductwork problems because it was poorly designed to begin with. These are some of the most common ductwork design mistakes that could be causing your air flow problems:

Ducts that are too small

When contractors who are not HVAC experts install your ductwork, they may fail to properly calculate the cooling load your HVAC system must handle. Many factors need to be considered in this figure, including the type of HVAC equipment, where it is located in the space, as well as the ductwork material (flex duct or sheet metal). It’s all too common for the load to be underestimated, and in that case you end up with duct problems caused by ducts that are too narrow.

Ductwork runs that are too long

If the location of HVAC equipment is too far away from the space to be cooled, you may have duct runs that are too long to carry the air to the space. That’s why equipment location needs to be carefully planned prior to beginning construction of the space.

Bends that are too sharp or too numerous

This is another duct problem caused by lack of planning. When ductwork design is not considered during the design phase for the space, ductwork installers may be left with little alternative than to create bends that are too sharp or numerous to effectively move air.

The good news is, an HVAC expert can help you sort it all out and get to the root of your air flow and duct problems. In many cases, a good cleaning or small layout changes can make a world of difference in the comfort of your commercial space.