Residential jobsite using open web floor trusses between the upstairs floor and the downstairs ceiling. the EC arrived and found no HVAC ducting installed were told by HO/GC to go ahead and wire the home. after wiring the residence and installing 30 + recessed cans and recessed flourescent fixtures and pulling all home runs and LVcontrolls and central vac lines in the truss space hvac shows up and install all of the heat supply runs in ductwork in same area. the return plenum is intended to be all of the open area in this same cavity. no panning of any kind.return air grates are cut in up stairs and the boots just stub down into the floor/ceiling cavity. down stairs some cold air returns are cut into the ceiling( will be 5/8 sheet rock when finished) some are panned off between the wall studs but feed into the open ceiling cavity.all wiring done prior to their start of the return ductwork. AHJ has been called, awaiting his decision. question is has anyone else seen this, if so what was the AHJ decision. none of thewire or fixtures are rated for plenum or Air tite . what are your thoughts on this style of return air plenum?
[This message has been edited by sparkystudent (edited 06-29-2004).]
I have seen this one time before on a house that I was inspecting and I shot it down for the reasons you give. In addition to the items you mention, you also cannot have gas piping in a residential plenum, so if there is any gas there they won't be able to do it.
Ryan Jackson, Salt Lake City
Re: return air plenum -entire floor cavity?#154163 06/29/0404:22 PM06/29/0404:22 PM
Probably nothing, this is residential. Around here, unless this is a very high end house, there is usually no mechanical plan.
Unless there was a way the EC could have known or even suspected that this was going to be done, I would say that because the HVAC guys got there after the EC it is their responsibility, especially if they designed it that way.
Hopefully common sense will prevail before any lawyers are inserted into the process. With all the cable and recessed fixtures in place at the time of HVAC roughin, the HVAC master should have been able to evaluate the situation and install accordingly, or at least, call the GC and start a change order for the "increased cost of ducting the return".
I'll just bet that the HVAC master stayed in the shop and sent out his lowest priced installer to handle the "simple new construction job", and that the installer just didn't give it any thought. Well. . .other than "hurry up and get out of here."