Two occupancies, one HVAC appliance

[Kao Chen]

2006 IMC and/or IFGC.

This a remodel in an existing structure. Two Business occupancies want to divide a larger tenant space into two smaller spaces and share one HVAC appliance. No rated walls, etc. so no problems with duct penetrations. One of the tenants will have no control over the thermostat (that doen't sound like a way to stay friendly). One space will be 1200 sq ft and the other 900 sq ft.

Is this prohibited by code? State code references please.

I do not know how you could ever balance this system.

Thanks in advance.

 

[BayPointArchitect]

2006 IBC 508.3.2 and 2009 IBC 508.3 Nonseparated occupancies.

Unless there is a rated wall required between the two businesses, there would be nothing to prohibit your scenario.

I believe that if a variable damper system is installed, then a second thermostat could control a second zone.

Or you could simply install a "placebo" thermostat and see if the second tenant ever figures out that it is not connected.

 

[vegas paul]

And place one of those non-functional "dummy" security cameras in the other suite, so the tenant thinks his neighbor can see if he's messing with the thermostat setting!

All kidding aside, how do you ensure meeting IBC 1204.1 when one tenant is closed, or goes out of business? Is there also only one electrical meter - and what if one tenant stops paying? Where is the return air for the isolated unit? Can you ensure adequate outside air and ventilation rates? (per UMC ch. 4 or IMC ch. 4)

 

[klarenbeek]

See IMC 403.2.1 item 1. Air can't be recirculated between dissimilar occupancies, for instance if one space is a restaurant and another is retail. ASHRAE does allow air circulation betweenany air class 1 occupancy into any other space but not in reverse--air from the retail space can go into the restaurant but not the other way around. I ran into this in a new office/ retail building with only one central air handler. the main tenant was a bank that occupied about a third of the building. About half a year later, a salon went into one of the spaces. The contractor installed 3 hrv's for the salon. All supply and fresh air came from the main air handler, with what would have been the return getting exhausted out through the hrv's. The air brought in through the hrv's was then dumped into the main air handler return system. As far as a tenant change, if it is for the same use, there would be no issue, if it is for a different use, our jurisdiction would require a permit and situations like that would be addressed at that time. As far as one tenant having no control over the stat, I guess he needs to complain to his landlord. It's not addressed in the code.