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Originally Posted by pavo6503

I've been asked to design the refrigeration system for a walk in meat cooler at a customer's house. He's a farmer/hunter and wants to store his meat in it.

The guy is set in his demands, so a couple things MUST be done his way:

He's had 2 railroad containers buried behind his garage and has a hole cut between the two of them. The walls and roof are being insulated with 6" foam, the floor is wooden. He's set on using an insulated exterior door for the entrance. None of this is my idea, so I know it's not the correct way to do this.

Anyway, each "room" is 6'9"x7'6"x18'7" (originally 8'x8'x20'). There is a 30" passage between the 2 boxes about 30" from the wall.

I'm suggesting he go with 2 evaporators separated with solenoids and a single condensing unit outside. We'll need about 20' of piping for each line, suction and liquid.

Where can I find the information, charts or program to determine what size equipment I need for this job? I've repaired plenty of these things but never designed one, so this is my "big break" into the process.

Thanks for you help.

Based on quick load calculations without knowing exactly what's in the box and the quantities of the product, here's what I get (based on 95degree condenser ambient and 35degree box):

Average duty calculation puts you at 9,300btu per box.
Heavy-duty calculation puts you at 10,700btu per box.

I think you'd be well covered if you based your equipment selection on 11,000btu's per box with that passage way you speak of. I, too, would try to convince the owner to use two separate condensers, but it's his money. I prefer HTPG's load calculation software, as some of the others will short change you on your btu's.

Originally Posted by Fridge Repairer

I call the guys at United Refrigeration to help me size things up...

That's exactly what I did. One store wouldn't give me an estimate during the call while another would hook me up even though e don't have an account with them. Huh? Whatever.

I call the guys at United Refrigeration to help me size things up. There really good at the branch I go to. Based on what he says id go with a slightly bigger unit. Its almost impossible to figure out your exact load based on the box. But being under ground and 6 inches on top insulated door being slighty larger than estimated as a regular box should cover you. Just my opinion.

Originally Posted by pavo6503

I'll take that to heart, but honestly we don't want this guy's business. I DO want some info on selecting equipment though, it is well worth learning.

Heatcraft has a very good source of information for load calculation and equipment selection in the Heatcraft Engineering Manual.

The load calcs are based on the method as published by ASHRAE. It's well worth the education to do a few hand calculations before stepping up to one of the many computer-based applications which are readily available.

Starting on p.21, there's an excellent section covering the proper selection of equipment for walk-ins. Study it and do a few for practice. If you have any questions, post them here and we'll be glad to help you out.

BTW, welcome to HVAC-Talk! Also, please fill out your user profile so we can get to know you a little better.

I'll take that to heart, but honestly we don't want this guy's business. I DO want some info on selecting equipment though, it is well worth learning.

great idea

I would consider using two condensing units so you would have some redundancy

http://www.hvacfun.com/f-design-refrigeration-syst.htm. At this site it has your dimensions and talking about 800 lb of meat

walk in refrigerator design

I've been asked to design the refrigeration system for a walk in meat cooler at a customer's house. He's a farmer/hunter and wants to store his meat in it.

The guy is set in his demands, so a couple things MUST be done his way:

He's had 2 railroad containers buried behind his garage and has a hole cut between the two of them. The walls and roof are being insulated with 6" foam, the floor is wooden. He's set on using an insulated exterior door for the entrance. None of this is my idea, so I know it's not the correct way to do this.

Anyway, each "room" is 6'9"x7'6"x18'7" (originally 8'x8'x20'). There is a 30" passage between the 2 boxes about 30" from the wall.

I'm suggesting he go with 2 evaporators separated with solenoids and a single condensing unit outside. We'll need about 20' of piping for each line, suction and liquid.

Where can I find the information, charts or program to determine what size equipment I need for this job? I've repaired plenty of these things but never designed one, so this is my "big break" into the process.

Thanks for you help.