Commercial HVAC sizing

[QFCK2001]

hi all, I am an electrical contractor and will be wiring for a new Japanese restaurant in a shopping mall. The mall is brand new so this restaurant is going to be the first tenant. It's about 6000 sq ft, and it has 2 ac units installed, I was told they are total 30 ton. The power supply is at 480v 3phase, one unit is with a 100amp breaker and the other one is with a 30 amp breaker, however the wire size is only #10. I don't have the nameplate for these units, does anyone know how much power they draw? The restaurant owner inform me that his HVAC company want to install another 30 ton of AC to bring it up to 60 ton or 1 ton per sq ft, is that overkill? By adding another 30 ton of AC, it will require upgrade the current service to at least 400 amp from the current 200 amp. I'm trying to help the owner out as he's a good friend of mine. What are your comment? Thanks in advance.

[Dallas Duster]

You should find the MOCP on the unit`s tag. When you find the model and serial number of the unit you should be able to track down some operating specs on the web somewhere ,if not here on this site. So I guess the answer to your electrical queston is that more information is needed .
As for the sizing question there are programs with load calculation that need to be performed to correctly size HVAC equipment to a specific space.

Do a search for load calculations. Good Luck

[ROYAL1]

Get an HVAC company to go in and spec it out.

[QFCK2001]

You should find the MOCP on the unit`s tag. When you find the model and serial number of the unit you should be able to track down some operating specs on the web somewhere ,if not here on this site. So I guess the answer to your electrical queston is that more information is needed .
As for the sizing question there are programs with load calculation that need to be performed to correctly size HVAC equipment to a specific space.

Do a search for load calculations. Good Luck

I'll try to see if i can get the serial number, but isn't 60 ton for 6000 sq ft is a little over kill? By the way,the ceiling height is 10ft and there are 3 exhaust hoods in the dinning area, all are 1 horsepower.

[yellowirenut]

if the restaurant is buffet style and has rows and rows of hot tables then u need TONS of cooling. hopefully the HVAC contractor has done a load calculation.

[btuhack]

Heat up equipment as per nameplate, if that requires service bump, so be it. The owner will have to recover the expense thru business. Don't comment or offer equipment capacity opinions if you don't have adequate background knowledge, BIG MISTAKE. If you want to stray away from electrical comments( your area of expertise ), try commenting on paint colors, or beverage choices, or waitress qualifications, etc.

[klove]

Heat up equipment as per nameplate, if that requires service bump, so be it. The owner will have to recover the expense thru business. Don't comment or offer equipment capacity opinions if you don't have adequate background knowledge, BIG MISTAKE. If you want to stray away from electrical comments, try commenting on paint colors, or beverage choices, or waitress qualifications, etc.

Even if he's your friend, this is your best piece of advice. Be his friend and tell him you'll size his service to whatever they install. And advise him to get someone reputable to tell him what he needs.

[Jwise]

I frequently eat greasy cheeseburgers at a joint that is about 1000 sq feet. There is 6 tons of cooling in the place. On really hot days the owner of the place has to turn on window units to make the place modestly cool.
There is a lot to consider when sizing a unit, number of people, equipment, square feet of glass, how many times the door opens, and so much more. Square feet is only a portion of what needs to be taken into consideration. Sizing is best left to HVAC professional. Wireing is best left to electricians.

[dan wong]

hi all, I am an electrical contractor and will be wiring for a new Japanese restaurant in a shopping mall. The mall is brand new so this restaurant is going to be the first tenant. It's about 6000 sq ft, and it has 2 ac units installed, I was told they are total 30 ton. The power supply is at 480v 3phase, one unit is with a 100amp breaker and the other one is with a 30 amp breaker, however the wire size is only #10. I don't have the nameplate for these units, does anyone know how much power they draw? The restaurant owner inform me that his HVAC company want to install another 30 ton of AC to bring it up to 60 ton or 1 ton per sq ft, is that overkill? By adding another 30 ton of AC, it will require upgrade the current service to at least 400 amp from the current 200 amp. I'm trying to help the owner out as he's a good friend of mine. What are your comment? Thanks in advance.

I am in Phoenix, Arizona. most of the Oriental super buffet here are 6,000 to 8,000 square feet. They have many steam tables in the dinning room (no exhaust fan in the dinning room, only in the kitchen). We hook up per architectural drawing, as it turn out, they size it as 2000 square feet per ton, no complain from customers.

I am assuming you have the blue print, and the local jurisdiction already issued you a permit to go ahead, (does the blue print suggesting additional 30 ton?). I am further assume you post your question here because the Engineer or the architect seeking information from you (They often ask me what requirement do I need, hence my assumption). To provide that information, your best bet is look at the manufacturer data plate then check with the architect or the electrical Engineer.

I am guessing; you have a twenty-five ton unit and a 5 ton unit; total is 30 ton, is that correct?. As a former electrical contractor, the 100Amp circuit is adequate for one 25 ton, and the #10 wire fused with 30/30/30 is ok for the 5 ton. (In Phoenix, Arizona that would be ok. Your jurisdiction maybe different, you being a electrical contractor you should know)

.

[Jwise]

I am in Phoenix, Arizona. most of the Oriental super buffet here are 6,000 to 8,000 square feet. They have many steam tables in the dinning room (no exhaust fan in the dinning room, only in the kitchen). We hook up per architectural drawing, as it turn out, they size it as 2000 square feet per ton, no complain from customers.

I am assuming you have the blue print, and the local jurisdiction already issued you a permit to go ahead, (does the blue print suggesting additional 30 ton?). I am further assume you post your question here because the Engineer or the architect seeking information from you (They often ask me what requirement do I need, hence my assumption). To provide that information, your best bet is look at the manufacturer data plate then check with the architect or the electrical Engineer.

I am guessing; you have a twenty-five ton unit and a 5 ton unit; total is 30 ton, is that correct?. As a former electrical contractor, the 100Amp circuit is adequate for one 25 ton, and the #10 wire fused with 30/30/30 is ok for the 5 ton. (In Phoenix, Arizona that would be ok. Your jurisdiction maybe different, you being a electrical contractor you should know)

.

Did you make a typo? I find this very difficult to believe. Did you mean 200?

[dan wong]

Did you make a typo? I find this very difficult to believe. Did you mean 200?

Yes. thats a typo. it should be 200 square feet per ton. Thank for noticing.

[QFCK2001]

Thanks for all the suggestion. They are adding an 15 ton unit, and I am bumping the service up to 400amp.