Model#
RGLH-10EAMER

My mother bought a house with evaporative cooling on the roof, and this kludgy furnace set up inside.

Question# 1: filter placement and number. The hand-drawn diagram shows two in a V pattern; I was able to reach up in there through the furnace and up, and work them out (dodging wires on the left) and instead of normal thick filters, they are these super thin, black grids with some super thin material across them. Some sort of washable filter? Would there be a third filter in this set up somewhere? I found the two "normal" filters leaning next to the furnace (see pics below).

Question# 2: Intake & Outflow. There are floor vents, and wall vents. I THINK the intake is the wall vents, and the blower is blowing hot air straight down into the floor and out of the floor vents. But the blower is on top, right under the V filters.

I don't know a thing about HVAC, and I've gotta believe I'm missing a filter somewhere. Thanks in advance for anything you can tell me. Pics below.

 

The evaporative cooler on the roof shoves air downward through the same upper vent - I just close those baffles.



This is the slot on the left that I have to ease the filters through. It's delicate enough with all that wiring and the switch box, even with the skinny filters below.


What are these filters? They look like they'd stop a dead cat, but not much else.


Thanks again for helping a noob.

 

From what I am seeing it looks like a typical upflow furnace. The filter that looks like a screen is the factory filter. Throw that away. Did they install a filter rack? I not sure what you mean by evaporative cooling.

 

Hey skaggsje, thanks for the reply. Those factory filter things feel like they rest in a V pattern; I have to do it by touch because it's up the duct above the furnace. There's a central strut that they rest in, then lean left and right. I assume there's something keeping them there.

An evaporative cooler, aka a "swamp" cooler, is a cheap form of cooling that works in drier climates. It's a big box on your roof that pumps water into some form of pad or sponge, and the fan pulls air through the pads and cools the air, then shoves the air into your house. They work well here.

I found an easier way to get thicker filters up in there, so if those are the only two filters, I guess I'm good to go.

 

Looks more like a downflow (counterflow) to me.
Yeah, toss those dead cat catchers and use the other filters. They won't stop much either but more than the strainers. If you can, and it is possible you can't, use a 2 inch thick pleated filter.

 

N,
Your return air comes from the top where your blower and controls are mounted and comes out the bottom which is a downflow furnace as Furd stated. Those are cheap factory installed filters that probably takes you longer to remove than they last.
What they could have done is install a new pull out filter unit on top of the furnace and then put the ductwork on that. One brand that is available in our area is called the AIR BEAR. It's a 5" pleated filter. You can Google it. They claim the dirtier it gets the better it works.
They are very easy to install on a new job and easy to maintain. It's like a draw. You pull it out and put a new one in.
You can still install one but you would have to cut the duct work and install it between the furnace and ductwork.

Good Luck,

 

If I wanted to retrofit a filter rack in the return above the furnace (that allows for better filters than the V-shaped rack) would that be something I could do myself?

 

You have to be very familiar with sheet metal.
You must determine the size of the filter unit.
Cut the return plenum
Make transitions for the filter rack. One for the furnace side that goes from the dimensions of the furnace to the rack and the second from the rack to the return plenum and join it all together again.
There are sheet metal tools that will be necessary and a sheet metal shop to fabricate what you need.

It's not that it's all that difficult but it's all in the measurements. Sheet metal does not stretch if your measurements are off.
IMO if you've never worked with it or had access to a sheet metal shop it would be worth getting a price to see if it's worth attempting.

You may be surprised. For a pro it's a small job.
You can buy the filter and have it installed. The SM place may know a tinknocker looking for a small job.
The good thing is you have plenty of room to install it. It's just a shame it wasn't done from the beginning. It would have been so easy.

 

If you don't have a/c, the filter is only there to keep the blower wheel clean, and it doesn't take much filtration to do that.

The factory filter is probably "good enough".

On the other hand, if there's a coil under the furnace, you should be using a decent filter.

 

Your biggest problem in retrofitting a decent filter rack is the exhaust vent (chimney pipe) crossing the face of the duct. If you are willing to move that (using a pair of adjustable elbows) then you can cut the duct and install a pre-fabbed rack. Here is one that I have, it is well made and has a door with spring clips to access the filter.

Furnace Filter Rack FAMCO

It will take any thickness filter from one to four inches without modification. You could install it with "S cleats" or with a combination of S cleats and "drive clips" if you want to buy a hand bender to flange the sheet metal for the drive clips. Or, you can probably figure out some other method of attachment. Seal all the seams with wide foil tape or mastic.

OR, you could replace your current return air grilles with a filter grill. Google furnace air filter grille for pictures and suppliers. If you use the return air filter grilles you do NOT need the filter(s) at the furnace.

 

I didn't even think about the exhaust pipe being in the way. Hells bells. There is some room on the side, but do they make "side loading" racks?

True, I don't have refrigerated air, so maybe I can get away with thin filters in the V rack. I'll see what the local pros want to re-route that pipe and fit a rack in there.

Thanks again - any advice is welcome.

Thanks for all of the help. I appreciate any advice

 

If you Google that air bear filter I mentioned it will come out any side you want. The front can be flush with what you have now.