Ventilation

[SteveDixey]

Are there any guidlines for ventilation in occupied rooms? I've come across various schemes that seem to vary in approach.

Some rooms I have been asked to look at will probably need a\c but I am concerned about ventilation as I feel a\c will not address this issue and despite feeling cooler, the room occupants are still going to fall asleep after lunch...

The rooms are between 5.5 to 3.8 kW cooling duty each and room volumes 63 cu metres (18 occupants max) to 38 cu metres (12 occupants max), all sitting.

One other room has around 11 kW cooling duty, 25 occupants for a 150 cu metre volume.

My gut feeling is fresh air ducted in via a central a\c unit but as building is already up and occupied, and costs tight, it may hit the "How Much!!!! barrier".

As this problem came up as an afterthought after the rooms got thrown up in a hurry, it may be fans in the walls of each room as a starting point and split or multi-split units.

Thanks

Steve

[frank]

Hi Steve

If you look on page 23 you will see that it is 10 l/s/person. Don't forget to add the fresh air load to your cooling equipment.

[Ravi]

Some rooms I have been asked to look at will probably need a\c but I am concerned about ventilation as I feel a\c will not address this issue and despite feeling cooler, the room occupants are still going to fall asleep after lunch...

Steve

That beats all calculations and guidelines The upper limit of ASHRAE comfort zone is 27C (this is subjective and 25C maximum should be ok at RH NMT75%). If you want to remove 11kW with OA then you have to have a temperature difference of about 19C considering 0.47cu.mtr/sec.

The temperature difference should be about 10C if you consider load from people alone (which is about a ton)