HVAC air outlets in a ceiling.

[bud--]

What are the considerations for putting heat/AC air outlets in a ceiling.

One room on the 2nd floor in a house (addition) has floor joists running the wrong way to put ducts in them. One option is running a duct in the attic (insulation not a problem) with outlets in the ceiling. The mechanic says ?I haven't seen it done." The other option is adding a soffit in the ceiling corner of a 1st floor kitchen (not desirable) with the outlets in the floor. Location Minneapolis, system includes AC. The rest of the 2nd floor and house has ducts in the floor.

Booster fan appropriate? Would the system balance for both heat and AC?

[gfretwell]

That is the usual place for the outlets here ... but we use a lot more AC than heat. You really need the heat to come up from low ducts.

[S. Barker]

I"ve not seen a two story that has the vents anywhere BUT the ceiling.

s

[John Grabowski]

Running ducts in an attic is not unusual in NJ. As for a booster fan and balancing I think only a qualified engineer could give you precise information. Maybe a good HVAC installer good give you a reasonable idea about what to expect.

You could install a ceiling fan in the room to mix up the air.

[Mikey S.]

Ceiling vents work a little better for A/C than for heat, as opposed to the rest of your vents ( low ones) which work better for heat than A/C. Hot air rises, cool air sinks, you can figure out the rest :-) Both will get the job done though as long as you have adequate volume and velocity, my house has most of the second floor vents in the ceiling too and it's fine. NW NJ here, warmer than your climate but we do get down to single digits a few times each winter. You might have to adjust a register or two or at worst a damper when going from heat to A/C but that's about it.

More important is to make sure you have adequate returns in all areas, without them all the supply air in the world won't do much good. That was the big problem with my house, I had a very uneven temperatures, especially with A/C until I added new returns in all the upstairs rooms and the top of the stairs rather than counting on the airflow under the doors and then down the stairs to the returns on the first and second floors.

[Big_Jake]

You don't get out often, do you?

About 80% of the 2 story houses I have been in have them on the floor. The remainder splits out about 50/50 into wall mounted (not near the floor) or on the ceiling.

Most mechanics can't even work on cars, don't ask them about your heating system.

Hard to say. Might be ok without it but -

Since heat rises, you might be ok there, but AC might be a little weak, but your best resource would be a qualified HVAC person, not a mechanic.

JK

[Robert Allison]

This thread has been quite educational for me. I live in the south and since our major load is AC, I would guess that that is the difference, but I have not seen air registers on the floor in a house. The only place that has registers on the floor around here are mobile homes.

ALL of the registers are on the ceilings around here, unless there is a situation that makes that less workable, such as vaulted ceilings. They are then placed very high up on the wall.

I can guarantee you that it will work for you due to my experience, but as another poster said, you might install a ceiling fan as that helps to circulate warm air when the heater is being used.

Get a good AC technician to design and install it.

[bud--]

The problem is it was the HVAC mechanic, with many years experience and working for a moderately large contractor, who said it. I know ceiling runs can be done but don't know what the trade-offs are, particularly with mixed ceiling and floor. IMHO the comment raised questions about the mechanic. And unfortunately not the only thing that raised questions about the mechanic. (It isn't my house. I'm looking for advice for the owner.)

Thanks for the replies.

[udarrell]

The Return air grilles should be at the floor level. If the diffusers throw the air down toward the exterior walls & adequate Returns are near the floor it will work okay.

- udarrell