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ibnibrahim2000
03-29-2011, 01:40 AM
My intention is to design the Ventilation and air conditioning system for a vehicle workshop of following features. Please let me know the conclusion I made at the end is practical? or if you have some other suggestions please provide. Any way according to the client Air-conditioning is necessary, although it’s not recommended for Vehicle Workshop. What’s your opinion on providing Package air conditioning through ducts?


Design Particulars of vehicle workshop
Total area ...... 1332m2
Total Volume.......8216m3
2 roller shutter doors......(2.5m*4m each)
There is office rooms attached to the workshop
6 Outdoor units placed inside the workshop (each of 2tone)
Separate fumes exhaust system already provided (One flexible pipe will connect to the silencer and emit the fumes out through pipe)
5 no of Exhaust fans provided (each 200 CFM maximum)
Roof.......Sand which panel with aluminum cladding


Ashre requirements
Minimum Ventilation rate in breathing zone........3.8l/s.person, 0.6l/s.square meter/ 6 no of air changes per hour
Minimum Exhaust rate......7.5l/s in case of fumes prevention, since we have fumes separate exhaust system we will consider average value 3.7, which is meant for parking garages.


Flow rates upon calculation
Fresh air.......880 l/s (Considering Minimum Ventilation rate in breathing zone)
Fresh Air.......13693 l/s (Considering 6 no of air changes per hour 6*8216m3/Hr So while converting to l/s we will get this)
Exhaust air.......4928 l/s (Considering 3.7 l/s . Area 3.7*1332)


Conclusion
1) Provide one ventilation fan supplying 7000 l/s fresh air (or 3 no of VFs each 2350 l/s)
2) Provide 5 number of Standalone units (Each of capacity 7.5 ton at 1300 l/s) total 6500 l/s and 37.5 ton (131.8 kw)
3) Provide one Exhaust fan extracting 5000 l/s (or 2 no of EFs each 2500 l/s)
4) Replace the 6 no of outdoor units from the workshop

Note: Workshop will maintain positive pressure

dandyme
03-29-2011, 05:28 AM
ok, i was with you right up to the point you started stating metric measurements.............

is there going to be a no breathing zone in this structure?:angel::whistle:

teddy bear
03-29-2011, 08:28 AM
If this is in a green grass climate, I suggest a couple of high capacity dehumidifiers to keep the humidity down when the outdoor dew points are high and the cooling load is low. Units the Ultra-Aire XL150H/Honeywell are capable of maintain <50%RH when there is not a enough cooling load.
Regards TB

ibnibrahim2000
03-29-2011, 10:32 PM
Dear TB, Thank you for your reply
But its not a green grass climate. Its in the Gulf region. So mostly the wheather will be hot. My concern is to know if the conclusions I made are practical?.....

flange
03-30-2011, 08:00 AM
I would offer a suggestion. I dont know what kind of vehicle workshop it is, but if its a bus depot for example, where you might find lots of diesel vehicles outside, you may need to treat the air for fume removal. There are bipolar products that can do that, as well as different types of filtration. This can help avoid that smell of diesel in both the shop, and office areas.