These are for a McDonalds restaurant. They were originally downshots. The return sucked wild under the 14" curb and had mold and moss 2-3" thick covering the entire curb. They were 5 ton units and had 4-8" supply ducts hooked up and 1-14" return. We had to increase the supply ducts, put 1" plywood over the curb, install the sheetmetal caps, and do all gas, electric, and drains. Again if you knew the job, they don't manufacture replacements so side discharge worked best.
Tough job, looks OK, would be nice to coat all that duct the same though, so it looks uniform.
Don't eat there though, they have new slogan since the big shot of mckiy d's croaked, "big macs cause heart attacks"
Around here Mc Donalds only puts in the best and Califonria being so high on their efforts for energy efficency we use automatic fresh air economisers usualy a engineering requirement. Surprised to see thos fresh air hood like that on a Mc Donalds.