Who is doing package units on a barn?

[wanderer]

Looking at a 5000 square foot combination barn in Kansas. Main area 16' tall, the rest 12' tall. I'd like to have it heated and cooled but I'm not really too happy with the idea of giving up a bunch of space in the barn for a furnace and ductwork. I'd really like to have a package unit set outside or even on the roof. I assume a pair of two -three ton units can probably do this pretty well.

My question is about putting it on the roof. Seems like a curb would be no big deal - my question is whether or not the ductwork can be omitted by doing this. Is it possible to have a plenum with some big air vents to blow the air where it's needed and have no ductwork at all?

No a fan of mini splits because of the maintenance and filter cleaning. Also I'd like a little better recovery so I can keep it semi cooled except when I'm out there.

 

[knucklehead 61]

you will need 10 tons or more to heat/cool a 5000 sq ft building.
a roof curb mounted unit with plenums into the space with a short return plenum & a longer supply plenum having grills on 4 sides will work, but running a couple sections of duct will get much better air distribution.

 

[danski0224]

Is it possible to have a plenum with some big air vents to blow the air where it's needed and have no ductwork at all?

Go to Home Depot and look up.

 

[wanderer]

Go to Home Depot and look up.

That's what made me think of this. Seems ideal in every respect except that I'll be doing filter changes on the roof. My building is a LOTY lower than home depot - do you think it will work well?

 

[wanderer]

you will need 10 tons or more to heat/cool a 5000 sq ft building.
a roof curb mounted unit with plenums into the space with a short return plenum & a longer supply plenum having grills on 4 sides will work, but running a couple sections of duct will get much better air distribution.

10 tons doesn't sound right at all. I have a 6000 square foot commercial building in town with 9 tons installed. It's heavily occupied and has much less insulation and many more penetrations.

 

[PoorUB]

Looking at a 5000 square foot combination barn in Kansas. Main area 16' tall, the rest 12' tall. I'd like to have it heated and cooled but I'm not really too happy with the idea of giving up a bunch of space in the barn for a furnace and ductwork. I'd really like to have a package unit set outside or even on the roof. I assume a pair of two -three ton units can probably do this pretty well.

My question is about putting it on the roof. Seems like a curb would be no big deal - my question is whether or not the ductwork can be omitted by doing this. Is it possible to have a plenum with some big air vents to blow the air where it's needed and have no ductwork at all?

No a fan of mini splits because of the maintenance and filter cleaning. Also I'd like a little better recovery so I can keep it semi cooled except when I'm out there.

Keep in mind they are not light weight! Can the roof structure carry the weight. A 5 ton unit is probably 500 pounds all located in one small spot. Then consider servicing the unit. An air filter change will require a trip on the roof. I am also thinking you will need closer to 10 ton.

We often set them on a stand outside of a building and run the duct work up the wall and into the building. The only down side is the duct needs to be insulated well.

You can also buy furnaces that can be mounted horizontally. That is what I did in my garage.

 

[wanderer]

Keep in mind they are not light weight! Can the roof structure carry the weight. A 5 ton unit is probably 500 pounds all located in one small spot. Then consider servicing the unit. An air filter change will require a trip on the roof. I am also thinking you will need closer to 10 ton.

We often set them on a stand outside of a building and run the duct work up the wall and into the building. The only down side is the duct needs to be insulated well.

You can also buy furnaces that can be mounted horizontally. That is what I did in my garage.

Thanks - haven't bought the building yet so getting it designed for the weight is NBD. I did consider sticking it on the ground, it just seems like a lot of extra expense simply to avoid changing filters.

 

[logical]

Withdrawn

 

[danski0224]

do you think it will work well?

Probably won't mix the air well. Commercial buildings are done like this because it's cheap.

 

[danski0224]

Put it on a pad on the ground.

 

[wanderer]

Probably won't mix the air well. Commercial buildings are done like this because it's cheap.

I wondered about that - but my hot dog heater throws heat across my garage just fine.

 

[reader2580]

A lot of times a rooftop package unit still has ductwork inside the building.

 

[danski0224]

There are diffusers that require no branch ductwork. Plenty of big box stores in my area are done just like this.

No or minimum ductwork means cheaper to install. That's why it is done.

 

[brewchief]

You're typically going to limited to 5 tons max per unit unless you have 3 phase power. If on the roof you have the potential for leaks and you will need a crane to set them and to replace them in the future.
Personally I'd prefer to have them on the ground.

As an HVAC guy I would do split systems before package units, much easier to get better efficiently and easier to replace when they fail.

 

[karoc]

These mount on outside of wall, but framing has to be planed. Two
Penetrations, one for supply then return air. I’ve service and install lot of these in younger life. Comes standard ac with elec heat or heat pump

 

[fitter30]

Without duct units are noisy and temps will vary from room to room.
Might like spiral round duct for a industrial look.

https://www.pinterest.com/ben_batesarchitects/spiral-ducts/

 

[Snapped-off]

These mount on outside of wall, but framing has to be planed. Two
Penetrations, one for supply then return air. I’ve service and install lot of these in younger life. Comes standard ac with elec heat or heat pump

Our 3 bards are mostly great. Although, I don't care for their S-bus control **** that the economizer damper actuator is tied into. It could be so much simpler.