VAV and Dual-Duct system calculations

[mitcham]

Could anyone give me some clues and rule of tumbs for VAV and Dual-duct hvac system design? Can you please specify where can I find comprehensive calculation details of how sizing cold and hot air ducts and selecting appropriate units for commercial and school applicatios using these type of systems?

thanks

 

[steam4]

mitcham,
Do you have access to a set of ASHRAE manuals? If not, try starting here:

http://www.ashrae.org/

 

[lilliput1]

Why do you want to go dual duct? This waste energy because of simultaneous heating & cooling. Also the system uses more space & more ductwork. Go VAV instead. You may need reheat (for heating loads & to avoid dumping at diffusers) but this would be at the VAV box minimum volume.