System short on return?

[George2]

They appear to be 10" OD flex pipes. That's about 1,000 cfm, (flex is more restrictive to the airflow) or 600 cfm short. Based on the blowers capabilities, 1,600 cfm of return air (at .08 static) is desired.

[George2]

Did I ever mention that the air rushing through the returns are sort of noisy?

That could be a sign of restriction.

[545GAlady]

Thanks for the information. I'll measure to make sure sometime. We do plan to replace the furnace next winter and we want to downsize, but since the heat pump is 3.5 tons, we'll still have to have a furnace with a 4 ton blower installed. Hopefully we can find a GOOD company to install the furnace and redo the ductwork as necessary. I don't think the company who installed the heat pump did a manual j. The old A/C was a 3.5 ton as well.

[545GAlady]

That could be a sign of restriction.

Probably so. You can't hear the noise unless you are standing right in front of the grilles.

[George2]

They appear to be 10" OD flex pipes. That's about 1,000 cfm, (flex is more restrictive to the airflow) or 600 cfm short. Based on the blowers capabilities, 1,600 cfm of return air (at .08 static) is desired.

I re-read this post.........I meant to say 10" ID (inside dimension). Sorry.

[545GAlady]

That's okay. I knew what you meant anyways.