I am starting an ICF house that will be using a commercial, self contained, forced air HVAC unit located outside the house. Like the ones on commercial rooftops everywhere. I think this may have some potential. It eliminates make-up air issues, A-coil condensation problems, venting and gas safety problems.

Does anyone have any info or comments for this application.

Commercial units are energy hogs. They are not designed with energy efficiency in mind. The units are large, noisy and have a short life expectancy [typically 10-12 years]. If you are going to use a "gas pack", prepare to be stuck with the high cost of energy for years to come.

Considering you are building an ICF structure, you would develop better comfort with a DX geothermal system such as the Geo Direct system by EarthSource Energy. An ERV will allow you to ventilate the home 80% more efficient than conditioning the air you pull from outside with the package system. A design such as this will save you $$$$$ over the systems life expectancy [typically 30+ years]. You can see a geothermal install on an ICF structure at LINK.

ICF........

If your area enforces any kind of residential energy code , you will need to keep in compliance.

Being on the roof it poses other potential problems, like flashing and insulating the penetrations, the duct work may get complex depending on your design. It wouldn't be my first choice even on a commercial building

I am late on this thread.  New to the forum and just catching up.  

I  have used a combo gas furnace/ac for years on my old doublewide.    I am going to get a new high efficiency one for the new sip house.  They come with SEER up to 15 now.  Search on the term "gas pack" to find them.  Most HVAC co's make them.

Dick

Dick,
Good info, I was having a hard time finding the HVAC systems for homes. I think it is a good idea to locate the gas furnace outside for safety and makeup air. The only question is performance.

Off the subject. SIPs are a good product and have their place...on the roof. ICFs are the way to build your walls. SIPs are energy efficient but are still made with wood. ICFs provide walls that can withstand 250mph winds and do not support mold growth. I was a construction consultant for 15 years and thousands of the problems I investigated would not have occurred or would have been minimized with ICFs.

ICF construction;

please note that besides wood, SIPs are also made with Steel, Aluminum, fiber-cement board and fiberglass skins

SIPs without wood are, by far, the minority, especially in residential home construction. ICF homes do not blow away or float away.

Gas packs in general have a short life expectancy and are limited to 80% efficiency. Given todays fuel costs, this is not a very good [efficient or cost effective] option. Split systems [gas furnaces] have a much longer life expectancy, higher efficiencies and better warranties. If the air conditioning system fails, you can replace it independantly. On a package system, you have to replace everything.

Not in Florida, I haven't seen any SIPs houses blown or floating away?