Choked blower due to compact blower compartment

hernat1ing

I don't know the proper term, but the highlighted text from @ProblemSolver post in this old thread correctly describes the issue with my furnace set up.

https://forum.heatinghelp.com/discussion/153820/new-shorter-furnace-and-what-to-do-with-the-extra-space

I have a Lennox Elite gas furnace that's 17-1/2" wide and 33" tall. It has a 16x25 side return. The return boot attaches to the non-motor side of the blower wheel. On the other three sides and bottom, there's very little space between the blower housing and furnace box panels which are insulated. It's a variable speed ECM motor. The connectors and mounting hardware block a portion of the narrow gap around the motor as well. Like all other blower wheels this one has a solid hub plate dividing the wheel in two halves.

This was there when we moved into the house. I know the best option would have been to open up the furnace bottom and install a return base, and then attach the boot to the side and the return base. There is a 9" transition piece between the top of the cased coil and bottom of supply plenum. Lennox sells a return base that is 7-1/4" tall. So, I don't know why the installers didn't take advantage of that gap and use a return base.

Are there any remedies to improve the airflow to the motor-side of the blower wheel without dismantling and starting over?

choked blower.jpg

mattmia2

What is the problem you are trying to solve? Is the esp too high? Is the rise too high?

HVACNUT

How about an actual picture of your specific furnace, other than whatever that was?

What is the temperature rise?

What's the static pressure across the furnace, and evaporator if there is one.

Is there an air filter somewhere?

hernat1ing

I had a blower motor failed and replaced just out of standard 5 year warranty because I am not the original owner. The technician didn't tell me why. I didn't see static pressure or temps noted in the report. He did tell me there was no blocking in the filter (brand new at that time), heat exchangers or the coil. The vanes on the blower were clean.

I don't have a specific problem now. I know undersized ductwork, oversized equipment, dirty filters, heat exchangers and evap coils cause problems. I know that old thread was about replacing an old furnace with a smaller footprint new furnace.

Just trying to get more details on the effects of compact/cramped furnace cabinet @ProblemSolver was talking about. I think it was very insightful beyond dirty filters and coils. Is @ProblemSolver still advising on this forum?

I attached a picture of the blower cabinet. It is standard Lennox elite gas furnace.

IMG_5355.JPG

EBEBRATT-Ed

What you have is a standard side inlet return on a standard up flow furnace.

It is 100% ok from what your picture shows. No need to create a problem where there is none.