Air Aonditioner Design - Ducts

How much information is still available from the data plates on the original Carrier units? The most important item for duct design will be the cfm (or m³/h) of air flow over the cooling coils. This is just a guess, but for quietness you might want to size the ducting for a velocity around 1000 ft/min (or 300 m/min). You will have to determine how much air is to pass through the various subparts of the duct system.

Theoretically following are few methods used for duct design in a.c applications. Constant Velocity method Equal Friction method Static regain method. Ductulators are available to size duct. Or use simple formula Q= AXV. Assume the recommended velocity as per the ASHRAE standard and size the duct .

1. First of all, you have to know the size of restaurant and various heat producing equipment in there. There are many ways of calculating COOLING load from that information.
2. You have to know the orientation of the place. Any adjoining buildings-air conditioned or not. How many story the restaurant is?
3. Know the weather outside and come up with inside temperature to be maintained etc, etc.
4. No of people, Light load etc. Hours of operations etc

There are many books on the subject but you have to do your Home work first and come up with all the data required as outlined above.

Then comes the selection of equipment and I agree with the answers given hereafter.

Wish I could help you more. I can suggest some books. manuals etc.

You can E-mail me at rajk@gmx.us. i will be too glad to help.

Good luck.

Thakral

leave it to a pro.

Read the above responses. Especially the one from CONWAYMECH. Then add in the possible loads from a possible unbalanced make up air/ exhaust system and changes in air cooled refrigerators, freezers, ice machines, etc.