I want to replace my 1962 furnace

[Frank's Trailer Works]

I did the search so, please don't tell me to do a search first... I have a 1962 Overlander. It currently has an International 1125 furnace that I cannot get to fire up. The fact that is is broken is a good thing, for there is a lot of rust in there and I would feel safer knowing that my family is not being exposed to exhaust fumes. I want to replace it with a new unit. The current furnace has a duct coming off the left side to supply the rear of the trailer and one that comes off of I don't know where to supply the front of the trailer. Can anyone tell me how I should proceed? I have gone to the Suburban website and looked at the various models. All the photos are of the right side of the unit, so I cannot tell if there is a supply on the left side to connect up the duct. I was hoping that someone out there has tackled this problem and knows what I need to do. The webite also stated that the outlet on the furnace is 4" round so I know I will need to transistion from round to rectangular. Of all the members out there someone has to have delt with this before.

[Moonstruck]

Hi,
if you're looking at the Suburban furnaces I know that models like the NT have ducts on both sides. Normally one on the left and the facility to have two on the right. I've looked around the Sub site previously and it's woefully light on tech information. A supplier will probably have more. My 31' Sovereign has a 30,000 btu heater so I would say you'd need at least 24k.
Find a price on an NT or SF if you need low profile and get the supplier to dig the info out as a small pennance for your order!
Marc

[markdoane]

Yeah, I did that.

I replaced with a Suburban SF model, which is the short profile model. If I id it again I would go with the NT model. The SF model is only about 8" high, but it is longer front to back than the NT. Because of that I needed to move the kitchen base cabinet out 1" further and make a filler strip for the back of the counter top.

I raised the furnace about 4" off the floor, so it was above the toe panel under the cabinet. That gave me enough room to route a 4" round under the furnace to supply a register for the front. There is a 4" round outlet on the right side, but the furnace is mounted too close to the cabinet wall to make a round to rectangular transition.

I used two of the round outlets on the left side of the furnace. The rear outlet elbows down, then immediately to a tee, one side goes under the furnace to supply the front register, the other side goes to the back. The backward facing leg, and the 4" round from the other furnace outlet both go to a 4" × 10" plenum.

The plenum has an angled 4×6 outlet that runs to the rear. It has one outlet through the floor with a damper, to direct air to the graywater tank, then it has a 2×10 register under the streetside bed and a 2×10 outlet in the bathroom.

I've posted some pictures in my photo album.

[overlander63]

IIRC, your furnace duct for the rear goes straight down, into a duct that goes under the floor. That may be why you can't find the rear duct.

[Frank's Trailer Works]

now I am hearing some answers to my question... thank you. The duct I cannot see is the one that goes forward.
markdoane, thank for that insight... I am realizing that there is not a direct replacement so modifications are required to reconnect the ducts.

More imput please... many points of view create insight.