IBC and ventilation
IBC and ventilation
(OP)
I am facing a frustrating situation and would like some insight from some other folks. Three years ago I designed an HVAC system for a church school. It was a two phase job: classrooms and gymnasium/cafeteria. The first phase was built immediately and the second was deferred until more funds were raised. Back then we were designing under the Southern Building Code (SBC). The SBC referred to ASHRAE for ventilation rates. Under ASHRAE I could reduce ventilation amounts based on time of occupancy. This in turn allowed me to lower the cooling tonnage.
Now the church wants to move forward with the second phase. Since we have switched to the International Code, the architect asked me to research how the job will be impacted by the new code. When i reviewed the ventilation requirements, I found that IBC doesn't reference ASHRAE at all. Nor does it allow for the reduced ventilation for transient occupancy. I found that the cooling load will approximately double - just for the ventilation load. As the original design was the basis for the budget, I don't see how the church can affrod the added tonnage.
Has anyone else run into this problem? Why doens't IBC leave the ventilation requirements up to ASHRAE guidelines?Any advice would be appreciated.
Now the church wants to move forward with the second phase. Since we have switched to the International Code, the architect asked me to research how the job will be impacted by the new code. When i reviewed the ventilation requirements, I found that IBC doesn't reference ASHRAE at all. Nor does it allow for the reduced ventilation for transient occupancy. I found that the cooling load will approximately double - just for the ventilation load. As the original design was the basis for the budget, I don't see how the church can affrod the added tonnage.
Has anyone else run into this problem? Why doens't IBC leave the ventilation requirements up to ASHRAE guidelines?Any advice would be appreciated.





RE: IBC and ventilation
What does God say about all this?
What are some of your parameters (unit size, sq. footage, etc.)?
RE: IBC and ventilation
Under the IBC I would have to design for the full 15cfm/person. This brings the cooling load to 75 tons.
I talked to the architect this morning and he brought up the point you did in regards to life safety. The entire job was reviewed by the city when it was originally designed and approved. We're hanging our hat on that and hope it gets passed. But it will have to get reviewed again since the permit for the multipurpose room expired.
RE: IBC and ventilation
Good luck w/this project, -CB
RE: IBC and ventilation
The heat pumps are each two-stage, so that helps.
What I'll probably end up doing is the show the ability to bring in the code minimum of 7000 and provide a CO2 sensor to modulate the outside air.
RE: IBC and ventilation
Next time perhaps God will be kept out of his home for safety reasons and statutory rules.
RE: IBC and ventilation
(Quark, had to get that in! -my first response to a church post..)