photograph lower and a bit closer.

It appears to be behind the cover between two white pipes and foil. It also look's like some knot head blocked access with the two white pipes.

This install is backwards. The coil should have been mounted on top of the furnace... I am assuming from your picture that air flow goes from bottom to top?

Not saying it can't work this way but it makes coil access that much difficult and coils are more prone to failure, plus the filter access if not in a grill would likely be just under this coil area.... blocked by condensate drain pipes.

Poor design.

I see a handle on the plenum above? Filter there? It appears to be the return at the top and must blow out the bottom.

Thanks for the responses so far everyone. To answer a few of the questions/comments, yes perhaps not the best install, but I have noticed driving through the neighborhood that everyone has pretty much the same install, so it either has it's advantages or the home builder just likes them.

I THINK it's a down flow unit, or has the ability to be downflow based on:

• The Payne PG8MAA/JAA 80% AFUE Gas Furnaces feature 4-way Multipoise design and through-the-furnace downflow venting.

• STANDARD FEATURES: Four-position furnace: Upflow, Horizontal Right, Horizontal Left, Downflow.

As for the handle up top, I have no idea what that's for, but if this is a downflow unit, possibly it is the filters. I pulled on it some and it didn't budge and the handle felt pretty flimsy like it would rip right off so I didn't push the issue. I may need to do that though.

Here's the requested photos.

"I have noticed driving through the neighborhood that everyone has pretty much the same install,"

Hmmm,maybe you should go next door and ask them to show you their filter.

klem1, hmmm maybe you shouldn't assume that I didn't. If they knew the answer for me, I wouldn't have to post here asking for help. A small neighborhood of mostly older folk who leave doors open 24/7 even when they aren't home. They are also more than happy to pay $100 every 2 months for someone to replace filters for them. The one lady I asked didn't even know she had a filter or that this unit was part of her HVAC system.

"you shouldn't assume that I didn't,The one lady I asked didn't even know she had a filter or that this unit was part of her HVAC system."

That was the extent of your effort? Regardless how old and rich the neighborhood is,someone has seen where the tech changes filters. It is rare that a homeowner can't tell me on arrival where unit is located and what part of house is best to enter from. Coupled with the fact you are unable to feel for air flow and tell us if the unit is upflow or downflow,maybe you should spring for a service call rather risk injurying yourself. There are things on ac systems that can remove fingers or give new hair-doos.

Vith, I think you're probably right. I read a little documentation from the manufacturer and though I didn't understand a lot of it, it seems that this unit can be mounted any which way the installer wants, and it did mention that an external filter housing would have to be used. It then said where that filter is placed is up to the installer as well. I'll start with this handle and see where it leads me.

The filter was changed before I bought the house, and is only a couple months old and with the temps being well above 100 I think I'll check the forecast and wait for the next semi-cool and cloudy day. That'll let me shut the unit off for a while and also get into the attic and take an in depth look at any ducting as well.

klem, you've been condescending since the very first post and love to just put words into my posts that don't exist. No the extent of me asking was not one lady, that was what we called an example. One of many. If you didn't want to help, and just be a douche, there's other posts. Sorry that my retired neighbors in a small subdivision of less than 10 houses isn't as special and smart as your customers.

Thanks to the rest that actually offered help.

Go to the hall or central point where the air return grate is and see if they are filtering your ducts from the return, which is a good thing imo.

trickyputt, I did attempt that actually. It's sort of what lead me to know the filter has to be here at the unit. I was up in the attic during inspection and know there is no filter up there anywhere either. There are multiple return points in this system, 5 to be exact although to be fair 2 of them are just on both sides of the wall so I don't know if you'd really count that as 4 or just 2. None of them are filtered however :/. The routing in general is very weird to me as I expected a very clear entrance into the unit and a very clear exit and not just 1 massive pipe. Since it's up off the ground, I'm wondering if that conceals some of it especially since the one set of returns doesn't line up with the visible connection in my pictures, unless it immediately does a 180 with a corkscrew. Very weird setup to say the least.

Go to a return and with a balloon and thread see if it comes out at the unit. You may be a jackpot winner for contractor grade installation.

Underneath the furnace looks like a make shift supply plenum, tinkered up with plywood and sheetrock. Unless there is actual ductwork inside of that.

I lol'd at this, thinking back to when my family was building our house and we didn't have a cover over 1 return in the massive archway at the very top. Of course I aimed at it with a ball and sunk it right in there and we got to run down to the basement and see if it had enough momentum to make it there.

This isn't a terrible idea though if Vith's idea doesn't pan out. One of the returns "should" be a rather straight shot to the unit so very few corners or anything to get it caught up or difficult to manage.

I really think it's gotta be behind that panel with the handle on it:

This is turning into a better mystery than I can find on tv.

I agree. I won't bump this post if it gets super old, but this weekend the morning isn't looking too bad so I may just shut the system off and go looking around.

There's a return vent right at the left edge of the horizontal ducting you can see in the picts. I mean like RIGHT there on the other side of the wall but perpendicular to the duct. I'd really like to know how that return ducting gets back. The return is too small to stick my head in so my current view is blocked to see if it goes much more than a few inches down.

If I find anything else good I'll let you guys know and see if I can't get a few pictures for giggles. Thanks again guys!

Friend has a rental property with an upflow gas unit installed in a hallway closet. The filter is horizontal at the bottom inside the blower unit, a panel on the lower front is removed for access.

So that handle is definitely where the filters are. Was able to get the panel off and there's 2 V mounted filters in there.