[supersparky]

I m trying to install the residental central heat air condictioning .I wonder to know is the Area of the size all the branch duct have to equal the main supply duct that come from the unit.thanks.

[iltos]

this might help
http://www.kbduct.com/ducting_designtips.shtml

[supersparky]

thank you for you help, i would like to know how to install the central air condictioning. and what kind the tools do i need .Thank you again

[Wino]

Originally Posted by iltos

this might help
http://www.kbduct.com/ducting_designtips.shtml

Probably if he had a wood workshop. That's for negative pressure dust collection systems. S/he needs info on HVAC ducting which will be a positive pressure system with lower velocities and static pressure. The design of HVAC system duct, while similar to negative is much more complicated.........depends on room sizes, number of registers, AC blower volume, available S.P., etc and to properly design, need to refer to ACCA Manual for recommended duct velocities for heating/AC systems.

Generally, yes, the main duct and branches should be close to the main duct area, sized to produce recommended duct velocities with as little S.P. losses as possible. If I remember correctly the velocity should be 75 ft/s for negative duct collection systems. Having successfully designed, sold and installed hundreds of dust collecting systems, I wouldn't even attempt designing an HVAC system.