Air Return question

2001 modular home with a 1992 Coleman furnace. (down-flow)
1)No return air grill(s) found…
2)No furnace filters found…

Take a look at the photo’s and give me your advise.

The unit is probably centrally located. The return air is the grill you are looking at in your pic. I assume the door is provided with louvers.

Pretty common in modulars.

The filter is either in the door you took off, is missing or is supposed to be behind the cover in your pic.

What are you showing in pic 2?

If that is B vent it needs 1" clearance to combustibles.

It looks to me the large flex duct goes to the roof at the much smaller 2" pvc vent, drawing outside air.

Where r all the HVAC guru’s???

were was the condenser ?

Not sure I understand what you are getting at?

The top cover grill should have the air filter. The top of the unit contains the blower (pulling air from the living area). More than likely that unit is located in the laundry room, correct? No closet door covering the unit, correct? If so, then door should be louvered/vented. The door or wall between the laundry room and living area should also be vented as to pull air from the living area.

Yes, correct on all accounts.

I’ve got the answers for the initial two questions, with your guys input, thank you.

On the top of the furnace, Is this a correct installation where the (larger)flex duct going to the (smaller) pvc pipe through the roof?

And as Michael pointed out about the 1" clearance. I can see where I need to call this out,

If that flex duct is drawing outside air through that small hole in the roof, with no rain cap, then why not just do away with the flex duct?

I was out of town and on a roof last evening I am struggling with the thought that the 2 inch is outside air looks like a standard plumbing vent.

I need to know what the flex duct connects to at the furnace or does it. Down flow furnace with supply registers in the floor and the return on the front of the furnace that flex duct makes no sense

I agree with all you say as that is what my thoughts were. The flex duct connects to a flange at the top of the furnace, I assume for the return air.

It does not look right but I (like you) cannot understand why it was done this way. Puzzling???

Surley the flex is part of the return could you see where it terminated above the furnace or did it just disappear into an attic area

Cathedral ceiling with no attic.

I just got a call from a local HVAC guy that said he couldn’t explain why it is the way it is but he could fix it by having the flex duct mounted above the door header with a new register instead of up through the roof.
That sounds like a plan.
What do you think Charley?

I understand that but where does the flex duct go when it leaves the furnace connection/flange

I can only assume straight to the roof. The furnace ceiling is dropped down approximately 12" to make it level.

Its for blend air apparently!

With the setup you’re showing, in manufactured homes, there’s usually 2 or more return air grills mounted high on the wall (above a doorway), normally in the living room and other large room such as master bedroom. As Mike H said (The top of the unit contains the blower (pulling air from the living area).

Did you notice any vents/grills at these locations?

Jim I think its for blend air for ventilating the attic and bringing in fresh air from outside.

Look up coleman deluxe blend air

My kids had a place in CO that had a furnace on each floor.

The only air return was at the furnace with the filter built into the door.