Hi everyone,
I am looking to account for C0 sensors in a basement carpak as part NC building model for LEED. My understanding is that for carparks the baseline model has contionuous extract (something like 5 l/s/m2) but in the proposed case the extract is non continuous and can be modulated by some kind of exhaust profile for the carpark which assumes how many cars are actually being operated in the carpark at any one time. Question is, what do we assume as a profile for this? Is anyone aware of any literature on diversities in carparks which will allow me to account for this more accuratly. I havent found anything in ASHRAE or CIBSE to date. Further to this, does anyone know where i can find information on diversites for occupancy for different space types in order to account for demand control ventilation also? cheers
Susann Geithner
PrincipalEmerald Built Environments
1297 thumbs up
December 16, 2010 - 10:57 am
We are also trying to account for a demand controlled ventilation in the carpark. So far it was denied and we have a very hard time to account for it at all. First of all you will have to submit it as exceptional method. That means you have to prove that this is not standard building practice in your area. To do that you will have to provide a recently published study or an incentive program, which specifically targets this efficiency measure. To show that this is not required by code is not enough and yes that means building A in one location might get less points under EA C1 than the same building in another location depending on the local standard praxis in newly constructed facilities. We have 5 projects with demand controlled carpark ventilation. We will no longer try to account for energy savings based on that, because of these requirements. Also the baseline building is assumed to have fans running during occupied hours only. My recommendation is to adjust the schedule (run time) in baseline and proposed building to be the same. So you reduced the impact of this energy user in your simulation. This is usually ok for the reviewers.
The easy part is the simulation, which you can do by adjusting your schedule to reflect the actual operation of the fans. If you want to know if you adjusted your schedule the right way and your prove of non-standard measure is sufficient, submit a CIR. Other than that there is an article in the ASHREA Journal (Febr. 2001) "Ventilation for Enclosed Parking Garages" We used that to calculate CO levels and therefore actual run time of the fans.
Good luck.