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jeffthearchitect
in attic - packaged HVAC
jeffthearchitect

I am certain most people will say it cannot be done . but all I need is one person who know how to ...:
Install Packaged H.V.A.C. fully in an attic . I am designing townhomes with no logical place to put A/C condenser(s) . my idea is to put 'all-in-one' packaged units in each attic (I have vertical runs designed in for ducts, etc.) . I am willing to put a vent on the front and a vent on the rear ... I am avoiding roof-top units due to the difficulty of maintenance .
any ideas ?
thank you
Jeff

ed21
Re: in attic - packaged HVAC
ed21

Why not talk to a manufacturer's rep (salesman) and see what they say is required.

keith3267
Re: in attic - packaged HVAC
keith3267

You can put a heater only system completely inside the attic but an AC condenser in a hot attic would not be very efficient. One system that would work would be a geothermal system, but they are expensive. You might be able to cut some costs if multiple units can share the same wells.

ed21
Re: in attic - packaged HVAC
ed21

With an outside heat pump unit a fairly small closet can handle heating and cooling of a townhouse.

dj1
Re: in attic - packaged HVAC
dj1

When you refer to "package a/c", a package a/c contains a compressor - and it usually goes on the roof.

With tight space, it's the solution for you.

Attic units are heaters with air handlers, yet the compressor has to be outside.

Talk to a/c installers, and ask them about roof top package units.

ordjen
Re: in attic - packaged HVAC
ordjen

I recently visited old friends in Las Vegas. They have a new house built by one of the nationwide builders. I found it interesting that the heating and A/C unit was in the attic, but that the attic was part of the house envelope, that is, it is both cooled and heated with insulation under the roof rafters, rather than above the ceiling. As this is a single level home, it makes the living area much more comfortable during the extreme heat of the desert summers. Obviously, LV is much more concerned with cooling, than with heating.

dj1
Re: in attic - packaged HVAC
dj1
ordjen wrote:

I recently visited old friends in Las Vegas. They have a new house built by one of the nationwide builders. I found it interesting that the heating and A/C unit was in the attic, but that the attic was part of the house envelope, that is, it is both cooled and heated with insulation under the roof rafters, rather than above the ceiling. As this is a single level home, it makes the living area much more comfortable during the extreme heat of the desert summers. Obviously, LV is much more concerned with cooling, than with heating.

Insulating at the rafters, done correctly, will keep the attic much cooler than insulating at the joists. Why is it done more frequently in the southwest? probably because of higher costs, and as you know, most builders aim to cut their costs to increase their profit, especially in tract homes.

You probably missed the condenser unit (the compressor) - it's outside.

A "combo package a/c" is a unit containing everything - furnace, condenser, exchange, control board, gas supply, electric supply and disconnect - all in one metal box, and is mounted on top of the roof, just like commercial units.

Mastercarpentry
Re: in attic - packaged HVAC
Mastercarpentry

Hmmm- an Architect making a design that won't work. Nothing new to me there, I've seen so many design failures I quit counting them ages ago.

Jeff, if you're designing the townhomes then you can design in everything they need in a manner that will work well and you should. Dreaming is good but real-life practicality is where the wins are at. I'm sure somebody somewhere makes something that will do what you seek, but it will come with an enormous cost up front and throughout the entire lifetime of the building which won't be long because nobody is going to want to bear such an unnecessary expense. Put conventional units on the rooftops- it's the best approach we have right now. Then later on use your idle time to make your dream happen- if you can make such a unit work efficiently the world will make you filthy rich buying it.

Phil

ordjen
Re: in attic - packaged HVAC
ordjen

dj,

I assumed the compressor was outdoor, with only the furnace and air handling unit in the attic. Why would anyone want the primary noise and vibration maker in their attic? This is one of the advantages of a "split system", the compressor stays outside, and the relatively quiet air handler is hanging on the wall, much quieter than a through the wall A/C and/or heat pump unit.

dj1
Re: in attic - packaged HVAC
dj1

I took the time and read the posting again.

Quote: "I am avoiding roof-top units due to the difficulty of maintenance .
any ideas ? "

Unless you can stand up in your attic, it would be easier to maintain and service a unit on the roof. I have an attic furnace and air handler with the compressor outside in one house, and it's a pain to service it. One: the roof is low, so I can't stand up there. Two: the attic is dusty. Three: The attic is also hotter than hell most of the year.

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