Furnace intake air Filter 2006 Monaco Camelot

[brokenarrow1244]

Has anyone added a filter to the intake grills for the furnace? It looks like it might be easy to do, but does the restriction cause any problem with heat buildup in the furnace? I would think the air volume may decrease. but it would be nice to get cleaner air. I just cleaned out the flex hoses for the air distribution. No wonder I sneeze and get irritated sinuses. Lots of dust.

[Rick A]

The air getting drawn in through those vents is pretty dusty. I used a loose woven furnace filter about 1” thick and it does trap some material. I made an appropriately sized wood frame and stapled the filter to it. 

[BradHend]

I put one of those blue filters you’d get from the big box stores in behind mine.  Probably doesn’t do much, but I like to think it does.  
On a side note, I’ve noticed barely any air coming out of the floor vents. (No, not from the blue filter😉)  The hose that goes under the dinette has lots of air pressure, however none of the floor vents do.  I’ve put my phone camera and a flashlight in all the vents to see if anything is obstructing the path, but from what I can see it all looks clear.  Would anyone happen know how the floor vent system was ducted on an ‘05 Cayman or know why I’m not seeing any air flow at the floor vents?

Sorry for intruding, @brokenarrow1244

Thanks. 

Edited March 11, 2022 by BradHend

[Idoc57]

Hi Brad,

Sorry for taking so long to reply.  I just came across your post late yesterday evening.  I can't promise you that I have the answer to your dilemma, however, I can tell you that I had EXACTLY the same problem with my '06 Cayman when I purchased it last year.  I could feel a decent amount of warm air coming out of the register under the toe kick of the kitchen cabinet, but almost nothing out of any of the floor vents.  I tried running 3' long fiberglass rods through the floor ducts as much as possible, putting suction on the ducts with a vacuum cleaner, but no luck.  Almost by accident, I noticed that there was a LOT of warm air coming out of the furnace access door outside the coach.  I pulled the metal intake grill off inside and did a little inspection of the blower.  At first everything looked OK, but I soon realized that someone had used that shiny "metal" duct tape to seal the 90 degree sheet metal duct to the floor.  The problem was that there was a 1/2" gap between the sheet metal duct and the floor and they only sealed the front and sides, so all across the back side (where you couldn't see) there was a 1/2" by about 14" gap.  Almost all the hot air was blowing out the back side and out the side of the coach rather than down into the floor vent intake!  I made a 1/2" thick spacer to fill the gap and fastened it in place so that there was nowhere for the hot air to go but down into the floor duct system.  Amazing!  All the floor ducts have a good flow of warm air coming out of them now.  Whoever the "genius" was that only sealed 3 of the 4 sides of the 1/2" gap had also installed the 90 degree sheet metal duct backwards!  I don't know if it came from Monaco that way or if maybe the furnace was replaced at some point.  Either way there's never a good excuse for shoddy work.  I hope this helps you Brad.  Good Luck!

Carey