What We Look For (And What We Don’t): Ducts & Vents — The Forgotten System That Impacts Your Comfort

Ask a homeowner why one room is always freezing or sweltering, and they’ll usually blame the furnace or the A/C. But more often than not, the problem is in the ducts. Crushed, disconnected, undersized, or just plain missing — ducts are one of the biggest sources of inefficiency in any home. And I always take a look.

I Check That Every Room Has a Source of Heating or Cooling

During every inspection, I walk every room, closet, and converted garage looking for one thing: a supply register. There should be at least one heat or cooling source in every room that’s considered “habitable space.” If there isn’t? That’s a big deal. The room may not heat or cool evenly—or may not be compliant for its intended use (like a bedroom or office).

Thermal Cameras Help Spot Hidden Problems

I love using my thermal camera when checking ducted systems. If the HVAC is running, the camera can show me which vents are putting out air—and which aren’t. Sometimes the difference is obvious: one room is ice cold, the other is lukewarm. That usually means a disconnected or leaking duct, even if the attic or crawlspace hides it well.

What I’m Looking For—And What I’m Not

✅ I’m looking for: missing supply vents, airflow consistency, disconnected or damaged ducts, obvious airflow restriction, poor attic/crawl insulation on ductwork.
❌ I’m not looking to: cut open ceilings, pressure test the system, or run CFM airflow diagnostics. That’s for ducting specialists or HVAC techs.

Common Duct Red Flags I See All the Time

Disconnected ducts – Usually found in attics or crawlspaces. Air ends up in the wrong place (like your attic).
Crushed or compressed flex ducts – Poor installation or too much storage weight can restrict airflow.
No return air path – Without a way for air to get back to the HVAC system, airflow suffers, and pressure builds.
Dirty or moldy vents – Not just gross—can indicate a filter issue, moisture problem, or lack of cleaning.

How This Affects Comfort & Utility Bills

If your ducts are inefficient, everything else suffers. Your HVAC system works harder. Your rooms stay uneven. And your bills go up. That’s why I include duct issues in my report. Even if the system itself works fine, poor distribution undermines the whole setup.

FAQs: Ducts, Vents & Airflow

Should every room have a vent?

Yes. Every habitable room should have a source of heating or cooling. Missing vents can affect comfort, resale value, and compliance.

Can you tell if a duct is leaking?

Sometimes. If there’s no airflow at a vent and no visible damage, I may use a thermal camera to look for signs of heat or cooling loss behind the wall or ceiling. For exact location or pressure testing, you’d need an HVAC pro.

Do you check ductwork in the attic or crawlspace?

Yes—if safely accessible. I look for disconnected runs, insulation issues, or physical damage. I don’t open sealed or inaccessible spaces.

Do you test airflow pressure?

No. That requires specialized duct testing tools. I use visual inspection and thermal imaging to document performance concerns.

→ Next up: Post 20: Water Heaters — What We Inspect (and What We Don’t)

← Previously: Post 18: Cooling Systems — Testing, Limitations, and What’s in Scope

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