Geothermal Heat Pump Damper Question

Specific Inspection Topics Inspecting HVAC Systems
1

I just had a client email me… he’s got a geothermal heat pump system and says that he heard a rattling noise that he tracked to a damper on the air return for the unit. He believes that the damper is supposed to be only used on an exhaust which he wouldn’t have being electric, and he wants me to write an addendum to his report since he thinks this is wrong.

I don’t know enough about HVAC to tell him whether this is normal or not…but I’ve read that dampers are used on these units to lessen noise? The house is a 2011 with solar panels if that makes any difference.

Anyone have any more info for me about this? Regretfully, I don’t have a picture yet. Trying to arrange a visit tomorrow.

2

This won’t have anything to do with the HVAC system in itself, but more about your report.
What you do is nothing… if you didn’t notice it at the time of your inspection, you cannot write it up just because your client sent you an email asking you to do so (at least not without going out there and seeing/hearing it yourself).
If you must write something up, defer it to an HVAC tech.

3

Thanks for the advice. I really want to come examine his unit better…for my own knowledge. Maybe I’ll hear the noise he’s talking about, but I think his main concern is the damper being installed incorrectly. I’ve done some more research and I’m wondering if it could be an “economizer” system?

4

Well, now the guy is changing his story a little :roll: He says there are two dampers on the exterior of the house…both positioned the same way - to allow air to escape. So the “intake,” as he called it, gets stuck shut and vibrates from the air trying to enter.

Since when does an electric heat pump have an intake and exhaust???

5

Does it have anything to do with this contraption? It basically just had a couple of filters in it.

CameraZOOM-20120731192248236.jpg
CameraZOOM-20120731192248236.jpg800×600 45.2 KB

6

Ok, did some more research… sounds like an ERV system

7

It depends on what the control device is that controls the opening and closing of the dampers or damper. Sounds to me like ya need to re-visit

8

well, I revisited and it was a ERV setup with the wrong type of damper on the intake. Whenever it called for air, the damper would shut instead of open due to negative pressure.

Good catch on the part of my client…bad miss on my part. I can’t be too hard on myself since it was the first time I had seen one. He was cool about it, and I made an addendum. All is well.

9

Generally John that is all that is required be honest and try to correct your mistakes most people would understand glad it worked out for ya