Inspecting air flow balance

We received a call from a client who is unhappy with the distribution of heat in their new townhouse. It is a 4 level townhouse with a FAU in the attic. Upstairs gets warmer than downstairs. Client’s heating guy wants to install a damper.

This dwelling was built in 2004.

First, HI’s don’t inspect for any kind of air flow or balance of an HVAC system.

Question: Is there an industry standard for the difference in temp change on a multi-level dwelling? Beyond checking for heat at each register, and air flow, at what point are you commenting on system equilibrium?

No. there is no home inspection standard For system design.

If you have a four level building and you don’t have four HVAC systems or zoned HVAC systems, it will be near impossible to create an even temperature gradient from one level to another. Hot air rises cold air falls.

A system designed for heating will not work 100% in cooling and vice a versa.

As far as you being responsible, it depends on how clear you were about what you inspected.

I just got off the phone with a “shopping for home inspector price” homebuyer.

He wanted to know what he was getting for the additional money that I was charging above and beyond the other six home inspectors he called.

When we discussed HVAC, he told me that every home inspector he talked to does HVAC inspections. Well guess what? No they don’t. HVAC contractors don’t even inspect HVAC equipment the same as I do.

so if you lead your client to believe that you will be inspecting the HVAC systems without being clear about the exceptions exclusions and conditions of your inspection, then it will be difficult to hide behind the SOP.

a look at your website:

how are you trained?

did you see air stratification?

from this, it looks like you’re screwed!

this is not an adequate test to determine equipment operation.

the fact that you have a complaint against you for improper equipment performance proves that this test is worthless.

My inspector did use IR to confirm heat blowing at each register - confirmed. Ducts are intact from the very limited observable portion, and confirmation the hot (100+) at each register. The question is about the variation of heat distribution which you answered at the beginning.

The complaint is that upper floors heat more than downstairs.

AC was not functional at time of inspections and a recommendation for evaluation was made in the report.

I understand that some HI’s perform a more in-depth AC evaluation. Some test refrigerant. Here a delta T test is a standard.

You were very helpful until the last sentence. You read a sample report and that has nothing to do with the heating question above. What do you do to test AC?

Thanks for pointing out the verbiage “Proper Ducting” which should have been, (and now has been) changed to “condition of ducting”.

What was the temperature difference between levels. If it is only five degrees on a normal system, he will not get any better than that. Some heating and cooling guys like to sell things.

We don’t document the difference in room temperature. Actually we never take a room temp reading, just the temp at the registers which were all about the same.

The complaint was about the upstairs rooms heating faster than the lower level. With only one thermostat located somewhere in the house, there is no way to create even temps throughout a house. They would need to upgrade to a zoned system.

What do other HI’s use as a criteria for this?

So the buyer nor his technician stated what the problem really is? I could not help the buyer unless I knew what the problem is. Just saying the upstairs is hotter than the lower level does not mean a zoned system has to be installed. The upper level will always be hotter, because heat rises. If this home has an open stairwell, you would not get the temperature between the levels within eight degrees, it is impossible without a zoned system. If most of the homes in that area do not have zoned systems then a zoned system would not be required to be installed. I would send over a heating and cooling technician that I trusted and see what he said, so you can put this situation at rest. It sounds like your buyer wants more than what is normal.

Is there a door at the bottom of the stairs?
Is the return in each room or are the doors cut back with a supply in the hallway?
What is the air flow at the registers?
Is it a dry heat at what velocity?
Too many variables to help solve the problem unless we get the full picture.
You will have the same problem if you call in a HVAC tech because he needs to know everything to solve it.

Heat rises. Single-zone systems are generally not capable of holding balanced temperatures in multi-floor residences.

The suggestion to install thermostatically controlled dampers sounds prudent.

Check out our website at and you’ll find that it is possible to evenly distribute your airflow/temperature using our patented comfort ring. We promise a maximum difference of 1.5 degrees from room to room, no matter how many floors are involved. We are a NEBB certified balancing agent involved in the residential,commercial, industrial world…you name it we can balance it.