Missing Return vents

Is an inpsector responsible if he/she misses the return vents in a room that has not good efficeincy?


b) Home inspectors are not required to:

  1. Calculate the strength, adequacy, or efficiency of any system or component

Heating / Cooling Systems

(e) The home inspector is not required to
v) The uniformity or adequacy of heat supply to the various rooms


Yep, I agree with David and he posted to the two SOP sections that apply. That being said, I do generally pay attention to airflow and will bring it up when there is a large imbalance. But I think the word “missing” (guessing it’s from the client and/or their HVAC contractor) is not really accurate since system installers (at least in my area) rarely put them in every room.


True! I only have two in my house. One upstairs in the main living area, one downstairs in the finished basement. Only supply vents in the bedrooms, baths, kitchen etc. plus the main living areas. Never had any issues.

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I think this part needs clarification.


This is way out in left field. Efficiency, show me anywhere where this is addressed in home inspection standards.

ASHRAE is an engineering group that tries to determine “comfort”, which is what you’re implying. They have yet to determine what comfort is to the entire population. It is not likely you will achieve anything any better. Do you know how to use a psychometric chart? That will get you close.


I’ve inspected old houses where no returns are present. A large gap under the doors serves for return, or leave doors open. Like @tglaze said, his house has only two returns, one on each level of the home. Prudent to point it out, but not a defect. Hopefully you’re not experiencing a complaint from a past inspection.


This is one of those things where you have to slow down a bit and study the situation. You need to determine if the room actually has a missing return, or if there is intended to be a different means of return. A good HVAC contractor would never install a forced air system without taking return air into consideration.

The air returns can be handled in a multitude of ways, especially on old construction that did not have ductwork when originally built. Look at the gap under the doors, placement and size of returns in hallways, open staircases, etc. All of these things can constitute a return air path.

I do find bedrooms and even whole floors without a method to return air, mostly in retrofitted situations. I put these in the report as a deficiency. I check for return air when I test the furnace, as I am walking the entire house at that time and taking a thermal image of every register.


I still think it’s funny that everyone keeps answering a question that may not even be about the lack of return air.

OP needs to come back and tighten up that question…


HVAC return vents serve the purpose of delivering air back into the HVAC forced air system, for conditioning & filtration, and importantly, "to maintain a balanced air supply.
1: It is not up to inspectors to consider engineering features, how many return vents are required in a system.
2: Nor are inspectors responsible to measure how much air is being supplied or delivered through each vent.
Vent Clearances, IE; a visibly obstructed vent might/may consider a mention.
Just my 2 cents.

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I’ve called out an obvious lack of sufficient return air sources, but only very rarely and usually a fix-n-flip or poorly done addition.

As stated by others, it isn’t our job to determine adequate return air.

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Thank you for all the responses and the fast responses. To clarify my question and condition, it was regarding an inspection in a rehab/flip house that it did not have return vents on the upper floor and i was aware of it in addition to the whole rehab was not the best. Though i mentioned nothing since i had the feeling i did not have to as well as i got a call of frustration by the client about it. But like Lon Henderson mentioned it will be good just to make a note of it in the reports.

Now that makes a big difference!

First, you can’t just report or talk about what something might be, without observation that supports the issue in question. However, what you just said raises several things you should keep in mind and try to observe indications that there is in fact a problem there.

  1. What Robert pointed out:

You can not effectively condition a space if the air in the room is not getting to the HVAC to be treated before it is delivered. A lot of talk is given to the supply air balancing, volume, flow rate, Delta-T etc. without consideration of the return. HVAC sucks, it does not blow. Chicken or the egg thing. Consideration of the return always comes first.

  1. You can not effectively condition two floors of the house with one HVAC unit (without using a zoning system).

Air stratification occurs between warm and cool air. In the summer, hot air in the house rises. How can you get that air down to a return on the first floor to be treated and put back on the 2nd floor? How do you get the cool supply air upstairs, and stay there when it is heavier than the 2nd floor air. Supply air flow drops and what gets up there, comes cascading down the stairs (and yes you can feel this and make an observation to report).

  1. A heating or cooling system can only be designed/installed to work 100% in one mode (again, without a zone system). Cooling needs a return high in the space to gather heat, and heating needs on on the floor to gather cool.


This is what occurs when it is done wrong.
They can’t put both the supply and return registers in the ceiling (found in homes with slab foundations), or just at the floor level (found in two-story houses with just on return).

You can diagnose these things with a piece of toilet paper and a thermometer, without the need of thermography. When you feel and measure inconsistencies, you can then recommend further evaluation.

Your initial question was a valid, you just didn’t ask it well.
But it still is not something required out of a Home Inspector.

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Yes, but simply put, as long as cold air has a means to return cold air back into the furnace.
Return ducts are usually placed in hallways, under stairwells, or in larger open areas of the home. Return ducts do not need to be placed in every room although I have seen that method.

As for your IR image. Shade from a tree canopy or from a building can create the same visual anomaly.

Believe me, that is not the case. I have done hundreds of these. Remember, I’m an HVAC System Design Engineer. That’s my job, diagnosing why people are freezing sitting in a chair when it’s 110 degrees at the ceiling and the furnace keeps cycling on and off.

As for the scan diagnosis, there are two wall angles, with a horizontal line at the sheet rock joint across the two walls. A tree can not produce that anomaly. They are almost always a diagonal pattern. This exception is geometric, a tree is not a geometric shape. If this was an overhang, or the neighbor’s roof shadow, the thermal line would be more defined.

This one was cold A/C air sitting at the floor and directly bypassing back to the return register located at the floor.