[hotrodjohn71]

Please see the photos. The entrance orifices of my heat exchanger (5 orafices) have what appears to be a fire retardant fabric. My best guess is that this is some kind of flame diffuser. What is this white fabric and what is it called. Better yet do you have a part number for the fabric inserts? The fabric in my unit here has deteriorrated and I want to replace it. Thank you.

 

[57TinkerMan]

My guess is that they are Low NOx inserts. If you look closer I think you will see that the "fabric" is protecting the end of the insert (metal screen). Don't know the part number. If you're not in California or location that requires them for emission control you may be able to remove them. Best to check with a Lennox dealer before doing that.

 

[hotrodjohn71]

Thank you 577. Do you know how the screen and fire retardant fabricks effect the NOx?

 

[57TinkerMan]

Simple explanation below:



https://hvacrfundamentals.blogspot.com/2014/10/nox-nox-whos-there.html

 

[user_12345a]

I would just get rid of them - california government bs.

on another forum people were saying that they reduce the efficiency and btu output by cooling the flame and carbon monoxide can actually be increased.

reduce nox at the expense of increasing co emissions and fuel consumption - sounds like a great plan, courtesy of the idiots who legislated putting cancer warnings on coffee.

 

[hotrodjohn71]

Ok, great. So if I remove them then the system should still work? I'd rather not replace them if they're not necessary.

 

[user_12345a]

the furnace will work fine without them if they are indeed low nox inserts.

i don't know if removal in an existing appliance is legal or not in your area.