Dining Room Occupancy

[tlhoo]

Trying to calculate dining room ventilation requirements for a commercial cafeteria. The most conservative occupancy count would be to simply count the number of chairs in the dining area. However, I've heard in the past that this number is discounted due to the fact that all tables are never completely full, meaning that all the tables may have some people at them, but the tables themselves are never full.

Anyone have any experience with this? Do you think it is good engineering practice to assume a peak occupancy around 80-85%? Just my first guess.

I know ASHRAE 62-2004 also allows a reduction of OA based on intermittent occupancy, so I am going to look into that as well.

As always, thanks in advance.

 

[imok2]

I would consider demand based ventilation with a CO2 sensor to overide the eononimizer setting, set at say 650-700 ppm.The rule of thumb for the ventilation of a dining room is 20 CFM/person

 

[VEEKRISH]

By ventilation, I presume you are refering to Outside Air. Considering that most public places do not permit smoking, you could tune down the air quantity to 15 CFM per person. In public spaces where occupancy tends to swing between extremes, it is appropriate to use demand based ventilation actuated based on CO2 sensors, from energy standpoint. Also, it would make sense to use an enthalpy wheel to conserve energy, would'nt it ?