Sizing a freezer

[modestmouse]

I have a customer who wants to increase the tonnage on his walk in.currently it has a 7.5 ton & 5 ton the dimensions are 70' x 20' x 10' he s wanting to replace the 7.5 with a 10 ton. it s a meat locker they try and hold it at -10.the 5 ton is actually a back up to the 7.5. I m not experienced in sizing freezers. 10 tons = 120,000BTU/hr. From 8am to 5pm there s alot of traffic from customers so the rate of air change is triple that of normal walk ins. I guess what I m wanting to know is the formular for sizing the equipment. 14,000 ft/3 , @ 90 degree outside ambient, -10 to 0 range.any help would be appreciated.

[nyrb]

Try this for starters. A proper load calculation needs to be done or you will likely just be spinning your wheels.

http://www.uscooler.com/?q=refrigera...izing-estimate

[Fridge Repairer]

You know how I size my freezers for the most part, I call Mike Mcgovern at United Refrigeration in Bensenville IL. at 630-521-9100. He will ask you questions like the surrounding box air temps, Type of door way, cooler panel thickness, Foam type, ect. He's good. They are very nice and helpful.

[bunny]

I have a customer who wants to increase the tonnage on his walk in.currently it has a 7.5 ton & 5 ton the dimensions are 70' x 20' x 10' he s wanting to replace the 7.5 with a 10 ton. it s a meat locker they try and hold it at -10.the 5 ton is actually a back up to the 7.5. I m not experienced in sizing freezers. 10 tons = 120,000BTU/hr. From 8am to 5pm there s alot of traffic from customers so the rate of air change is triple that of normal walk ins. I guess what I m wanting to know is the formular for sizing the equipment. 14,000 ft/3 , @ 90 degree outside ambient, -10 to 0 range.any help would be appreciated.

If you are saying the customer currently has a 5 HP and 7.5 HP compressor, he most certainly does NOT have a 5 ton and 7.5 ton systems.

Best to check the compressor capacity chart and see what your actual capacity is. You will find for your application it quite different than 1 HP per ton.

[Dad]

There are calculators in the Educational Forums.

http://hvac-talk.com/vbb/forumdisplay.php?f=205

[modestmouse]

Thanks everyone

[hceptj]

I usually do the load calcs myself but anytime I'm not sure, I stop by United (sort of like Fridge Repairer) and they have a form you can fill out and they will get the proper equipment spec'd out for you.

I use the Heatcraft program:

http://proselect.heatcraftrpd.com/he...13531708787439