General Questions on Various Furnaces

[4my mom]

My mom is trying to replace 2 gas furnices and A/C units with one. The newest unit is 35 years old.
She is looking at a 93+ effeciency with a 15.5 SEER A/c unit.
My questions:
1. One contractor stated that humidifiers were manditory for 93+ furnaces. Is that correct? Mom lives in Iowa
2. A different contractor want to change the pipes for a 16 x 8 to a 20 x8, 16 x8, 12 x8, 10 x8. He stated that by not changing the pipes it would be noisy. Is this correct?
3. A third one want to run a pipe across the ceiling to a sink in the basement when there is a drain close to the furnace. Any ideas?
Thanks
Andrea

[Dof3]

Wow that is alot going on. No it is not mandatory to put a himidifier on a 90+ furnace. If there is a floor drain right by the furnace why not use it. The ducts you are talking about changing may have to be, to use one furnace instead of two. Without looking at the job it is hard to tell.Have someone do a heat/cooling load on the house and make sure they have properly sized equipment.By reducing the size of duct work as it goes will make the air travel better.

[BaldLoonie]

First, Mom doesn't need any 15 SEER A/C in Iowa unless she just wants a fancy unit. There would be no economic payback. Even 12 SEER would be a long term investment.

Hard to say on the rest. We'd have to know what size furnace she needs and know how much air it has to move. Then know exactly what size ducts she has. Unless the ducts there are grossly undersized, pretty rare to have to do that much work to upgrade a furnace.

[hvacfella]

'First, Mom doesn't need any 15 SEER A/C in Iowa unless she just wants a fancy unit. There would be no economic payback. Even 12 SEER would be a long term investment.
'

ME: Agree. A 15 seer is an overkill (especially in the Midwest) unless mom runs the a/c day and night cause she has severe allergies and must have the windows/doors closed. I doubt mom would like the physical size of a 15 seer a/c unit --- tell her its roughly the size of half a car !

[4my mom]

Thank you for all of your information. I have passed what your comments were to my mom and she is ready to make her decisions.
Thanks, Thanks, Thanks

[badbatch]

Where at in Iowa are you? I'm in Iowa City if I csan be of any help.

[4my mom]

We are on the other side of the state. Southwest of Des Moine about 75 miles.