Help with HVAC

[William Slade]

Had one today.. and it appears the furnace is installed upside down... is this kosher? There is a big square plenum in the crawl space directly under the furnace.... never seen this kind of set up.. help...b

[Bruce King]

Picture is small but it sure looks upside down! I doubt if that is allowed.

I found a horizontal one installed upside down on a new house.

[John Dirks Jr]

If that is a wood floor then it looks like there's problem with clearance to combustibles with the vent connector. So add that to the list.

[Ted Menelly]

It is upside down and that unit is sure not made for that in the slightest, blower or not. The combustion chamber is on the top and the heat exchnger is on the bottom etc etc etc. Nothing is right about the set up at all.

[Michael Larson]

There are multi-position furnaces but your pic is too small to determine if it is one.

Example (http://www.allstyle.com/installationManuals/Furnace%20Manuals%20and%20Parts/ABAInstallersManual.pdf)(PDF)

Pull the manual and check.

[Bruce King]

That doc does not show any vertical mount unit with the exhaust out the bottom.

[Art Palmer]

I've seen this on a number of occasions. The only way to be sure, is to review the manufacturer's data plate. It will state if it is approved for both updraft and downdraft positions. It's difficult to tell in your photo.

[William Slade]

I wish there was some kind of sticker or plate to tell me who manufactured the thing... can't find any documentation... writing it up that's it's installed upside down and need to have a qualified HVAC look at it... thanks for all the advice you guys are the best..b

[Ted Menelly]

I wish there was some kind of sticker or plate to tell me who manufactured the thing... can't find any documentation... writing it up that's it's installed upside down and need to have a qualified HVAC look at it... thanks for all the advice you guys are the best..b


You don't have to worry about that. That furnace is designed for an up draft. Everything on and in it tells you that. You would not have the burners at the top of the heat exchanger as well as the vent coming out the bottom. It just does not work that way.

[Jerry Peck]

You don't have to worry about that. That furnace is designed for an up draft. Everything on and in it tells you that. You would not have the burners at the top of the heat exchanger as well as the vent coming out the bottom. It just does not work that way.

I've been trying to make out what was being shown in that small photo (William, why not take photos in a higher resolution so more detail can be seen?) --- Ted nailed it above ... now I can make it out and see it ...

... 'the burners' are ABOVE 'the vent' - heat and combustion gases rise, not settle. :eek:

[William Slade]

Yeah Jerry sorry bout the pics... not used to sizing... will have my son give me a hand on that... thanks for the help..b

[Jerry Shipman]

Sorry to disagree Ted, but many manufacturers have furnaces set up this way and allow upflow, downflow, or horizontal installations with the same furnace. The furnace is assisted draft (see the inducer motor?) and pulls products of combustion through the heat exchanger regardless of the orientation of the burners with the heat exchanger.
All manufacturers do require some type of combustible floor base or that the furnace sit on an approved ac coil or coil box when in the downflow position. This is required to observe proper clearance to combustibles (the floor in this case). Also, many require some type of downflow vent guard kit that will cover the single wall vent pipe, or a B-type vent to avoid the kiddies touching a hot vent pipe.
The only way to know for sure is to get a copy of the manufacturers installation manual for that furnace.
William, the manufacturer should be on the rating plate, along with the model of the furnace you're dealing with.

[William Slade]

Jerry... there is no documentation available to tell me where it's made or what position it's designed to be installed... I had never seen one quite like this so you fellas have given me a direction..thanks b

[Jerry Peck]

Yeah Jerry sorry bout the pics... not used to sizing... will have my son give me a hand on that... thanks for the help..b

William,

I enlarged them as much as I could without losing detail enough to see and annotated the photo, one shows the way it should be (I obviously doctored the photo to show it that way) and one shows the original photo with the sections labeled and making it obvious why it is upside down - at least obvious to Ted and myself, we could be wrong, but flames and heat tend to go up and rise instead of go down, which is also shown in the multi-position installation information Michael linked to.

[Jerry Peck]

Sorry to disagree Ted, but many manufacturers have furnaces set up this way and allow upflow, downflow, or horizontal installations with the same furnace. The furnace is assisted draft (see the inducer motor?) and pulls products of combustion through the heat exchanger regardless of the orientation of the burners with the heat exchanger.

Jerry,

Do you have documentation for that orientation?

I know I would like to see it and learn, right now, though, see my photos on my other post to William to explain why it does not work, or work well.

I have been wrong before, and will be wrong again ... many more times again ... so if you have that documentation it would sure be helpful.

[Lisa Endza]

William, you are in our state (CO), email me at fastreply@nachi.org and I'll get you a code to get free access to Advanced HVAC Training course - InterNACHI (http://www.nachi.org/hvacclass2008)

No charge.

[Craig Ervin]

Carrier makes a 4 position furnace, most furnaces are not 4 position. They will be Horizontal left (or right) and up or down flow.

There are 3 position furnaces out there too right or left and either up or down.

A lot of the older ones are 2 position up-flow and horz. right or down flow and Horz. left. Too many makes and models out there, you need to see the installers guide to know for sure.... but....

Whats the big clue on this one? The flue pipe is upside down!!!! :eek:

[Scott Patterson]

I would have to say it is wrong as well. Heat rises as well as the products of combustion in the hot flue gas. Look at the wood floor, it shows signs of distress. Most likely from the heat of the flue pipe.

If you don't feel good about calling it out as being wrong; you should call it out for just being dang stupid. It is a screwy unconventional setup and unconventional things tend to act in unconventional ways!

[Markus Keller]

Color and configuration looks like a Janitrol/Goodman. Pretty sure they didn't make a 4 position. From what I remember the downflow was always a separate unit and did not look like that.

[Matt Fellman]

I agree that looks like a Goodman.... I've seen lots of similar installations in new homes in my area. I scratched my head the first time I saw one. I'm pretty sure I've seen an ID tag or read some instructions that rate it for up or down flow.

Like the others mentioned, the best thing you can do is get the specs for that unit and look it up. Everything else is just speculation.