New home construction furnace location

[JMER817]

In the process of building a new home with forced air heat. I noticed a possible issue with the location of the furnace looking at the print before start of construction and was told that it shouldn't be a problem. Well, here we are and the issue has arisen. My basement will be half finished basically down the middle where the main beam sits. The east side will be unfinished and that will be where all the utilities will be placed. The west side will be drywall and carpeted. The plan was of course to place the furnace on the east side in the unfinished area. Problem lies with running the main ducts which typically set next to the main beam and run the length of the basement. There is a set of stairs on the furnace side of the beam so the main ducts cannot be ran on the same side of the furnace. So now we either have to move the furnace onto the "finished" side taking up quite a bit of finished area and leaving a bump in the floor plan, or option two cross a duct under the main beam from the furnace to the main duct. I'm leaning towards option two. I'm told this crossover duct will be rather large and both the builder and heating / cooling guy seem to be leaning towards moving the furnace. This whole discussion took place over the phone. I plan on trying to meet with the two hopefully next week to discuss further. Difficult to time this. So, does anyone on here have an example of what I am talking about? Any other options? I'm wondering if the crossover duct can be place about the beam between the 16" on center floor joists? Does coming down under the beam and then back up hurt the efficiency of the furnace?

 

[yelbike]

Efficiency really won't be effected but you may have an air flow issue at the end of the run. What size is the house? Square bungalow?

 

[JMER817]

1890 sg ft ranch. Roughly 62 x 32, furnace will be in center of basement

 

[s219]

What kind of ducting? Is it the large flexible/insulated ducting with the shiny foil exterior? If so, I wouldn't worry about your proposed solution #2. Almost all new houses I have seen use that ducting coming out of the air handler, and it will do all sorts of turns and bends as it runs out to the rest of the line. Very few homes have a perfect setup for the HVAC raceways, and they should be able to deal with it.

For our new home, the 1st floor zone is a pretty straight shot from the mechanical room (off garage) out into the crawl space. But for the 2nd floor zone, the duct goes up, then turns horizontal, then back vertical. That's just because the only available raceway up into the attic was not exactly aligned with the mechanical room. We had to build a bump out in the garage ceiling to accommodate that "shift" of the duct. No big deal.

I guess the main issue could be how the furnace is configured, as certain units do have specific designs for vertical or horizontal, or left or right, discharge configurations and they are not meant to be flipped around (they assume you are spec'ing and ordering the right one and that's all there is to it).

 

[Tollster]

Try to keep it towards the middle of the house length wise, then you can run a main duct down the middle and short runs off that to the upstairs rooms off that, it will reduce the cost and be fairly consistent.

 

[BethelHntr]

In the process of building a new home with forced air heat. I noticed a possible issue with the location of the furnace looking at the print before start of construction and was told that it shouldn't be a problem. Well, here we are and the issue has arisen. My basement will be half finished basically down the middle where the main beam sits. The east side will be unfinished and that will be where all the utilities will be placed. The west side will be drywall and carpeted. The plan was of course to place the furnace on the east side in the unfinished area. Problem lies with running the main ducts which typically set next to the main beam and run the length of the basement. There is a set of stairs on the furnace side of the beam so the main ducts cannot be ran on the same side of the furnace. So now we either have to move the furnace onto the "finished" side taking up quite a bit of finished area and leaving a bump in the floor plan, or option two cross a duct under the main beam from the furnace to the main duct. I'm leaning towards option two. I'm told this crossover duct will be rather large and both the builder and heating / cooling guy seem to be leaning towards moving the furnace. This whole discussion took place over the phone. I plan on trying to meet with the two hopefully next week to discuss further. Difficult to time this. So, does anyone on here have an example of what I am talking about? Any other options? I'm wondering if the crossover duct can be place about the beam between the 16" on center floor joists? Does coming down under the beam and then back up hurt the efficiency of the furnace?

running ducts under a beam isn't a problem as long as they're sized correctly, One down fall is appearance with ducts not hidden. Is there any space above say joist blocks that can be removed?

 

[jimpen]

What about using just concrete blocks to mount the furnace on right next to finished area, and then run the pipes from there?

 

[lockhaven]

another course of blocks would make it possible to drop the basement ceiling below the ducts and still have plenty of head room

 

[fishheadbob]

I had a similar issue retrofitting my 1830s vintage house. People weren't very tall then, the furnace is chimneyed in the old section of basement, ductwork extends into the 1970s addition, the joists in one area run in a different direction than in the other. I bump my head a lot.