Building a refrigerated warehouse

[gaz]

Hi Guys,

I am new here and would appreciate any feedback.

Firstly I must say that I know nothing about engineering/refrigeration as I run a business and am looking at building a new refrigerated warehouse for my business.

Right now I have a consultant who has been servicing my old warehouses running on *****.

OBviously that's what he knows best.

Another friend who is running on ammonia is telling me ammonia is the way to go.

So I am confused in the midst of all these advice.

What direction should i take?

And what are the steps or procedure I should take that are typical of building a refrigerated warehouse?

Thanks in advance.

[Josip]

Hi, Gaz :)

Welcome to RE forums.


Hi Guys,

I am new here and would appreciate any feedback.

Firstly I must say that I know nothing about engineering/refrigeration as I run a business and am looking at building a new refrigerated warehouse for my business.

Right now I have a consultant who has been servicing my old warehouses running on *****.

OBviously that's what he knows best.

Another friend who is running on ammonia is telling me ammonia is the way to go.

So I am confused in the midst of all these advice.

What direction should i take?

And what are the steps or procedure I should take that are typical of building a refrigerated warehouse?

Thanks in advance.

Both ideas are good (I am ammonia guy and I will support ammonia;)), but....

To give you some good advice you must give us full info about your refrigerated warehouse - cold store:

-goods (one or more/mixed or not, etc...)
-cooling temperature -from X (C/F) to X (C/F)
-quantity of goods
-just cooling or some other activities like sorting, packing , etc...
-your idea about cold store..seems you want multipurpose cold store

Some other guys will come maybe with additional questions, but that's the only way for help..

Best regards, Josip :)

[gaz]

Hi, Gaz :)

-goods (one or more/mixed or not, etc...)
-cooling temperature -from X (C/F) to X (C/F)
-quantity of goods
-just cooling or some other activities like sorting, packing , etc...
-your idea about cold store..seems you want multipurpose cold store

Some other guys will come maybe with additional questions, but that's the only way for help..

Best regards, Josip :)

Hi Josip,

Thanks for the prompt reply.

-goods (one or more/mixed or not, etc...)

300 sku varying from meat, dairy produce, to dry goods

-cooling temperature -from X (C/F) to X (C/F)

1) -18 to -20 degrees celcius (freezer)
2) 1-4/5 degrees celcius (chiller)
3) dry warehouse - normal room temperature


-quantity of goods

1) freezer - 1500 MT - 2000 MT capacity
2) chiller - 200 MT capacity

-just cooling or some other activities like sorting, packing , etc...

Need pick face and after pick area - Seems like this is the hardest to estimate how much space needed.

There will be a production room but that's a separate matter.

-your idea about cold store..seems you want multipurpose cold store

Yes multipurpose as I import a range of food products.

Anything else, please ask thanks.

[Josip]

Hi, Gaz :)




300 sku varying from meat, dairy produce, to dry goods


1) -18 to -20 degrees celcius (freezer)
2) 1-4/5 degrees celcius (chiller)
3) dry warehouse - normal room temperature


1) freezer - 1500 MT - 2000 MT capacity
2) chiller - 200 MT capacity


Need pick face and after pick area - Seems like this is the hardest to estimate how much space needed.

There will be a production room but that's a separate matter.

Yes multipurpose as I import a range of food products.

Nice project;)

In freezer are you going to keep ice cream? Anyhow here you must use direct cooling system.

For chiller and A/C area is better to use indirect system with enough capacity for production area/room later on. Did you think about FIFO system for dairy products -chiller room/s and for A/C too?

What about capacity for A/C room (chocolate, sugar, salt, rice, flour, candy -wafers, caned goods) ?

4 big rooms (freezer room, diary-meat chiller room, A/C room) or maybe couple of smaller rooms

Handling (receiving/delivery) area can be quite specific (unloading/loading ramps for big or small trucks, fast doors, number of fork lifts, etc.. ) but you know daily traffic in tons, or number of daily trucks in/out...anyhow must be discussed well.

See this also, quite a lot to read:

http://www.refrigeration-engineer.com/forums/showthread.php?t=2188&highlight (http://www.refrigeration-engineer.com/forums/showthread.php?t=2188&highlight=pallets)
http://www.refrigeration-engineer.com/forums/showthread.php?t=2070&highlight (http://www.refrigeration-engineer.com/forums/showthread.php?t=2070&highlight=pallets)
http://www.refrigeration-engineer.com/forums/showthread.php?t=7858&highlight (http://www.refrigeration-engineer.com/forums/showthread.php?t=7858&highlight=pallets)
http://www.refrigeration-engineer.com/forums/showthread.php?t=7757&highlight

Recently we design and install one similar ammonia/glycol cold store in KSA (±20000 m³) but each new project is a new challenge.

Hope this is of some help to you;)

Best regards, Josip :)

[gaz]

Josip,

Thanks for the great links.

By the way, 1 very important question - I just realised my warehouse frontage will be facing west, which means the loading/unloading dock will be facing the afternoon sun.

Of course it is not ideal, but will it be a barrier or huge disadvantage?

[Peter_1]

1) -18 to -20 degrees celcius (freezer)
2) 1-4/5 degrees celcius (chiller)
3) dry warehouse - normal room temperature

1) freezer - 1500 MT - 2000 MT capacity
2) chiller - 200 MT capacity

-just cooling or some other activities like sorting, packing , etc...


What size do you have in mind?
What's 1500 MT and 2000 MT capacity?
What is 300 sku?

Whatever you want to build, insist that a system is installed with an as low as possible condensing temperature.
Can you use warm/hot water in your business?
What's the average temperature in winter and summer in your country?

[lana]

Hi everybody,

I think the question gaz asked is common everywhere.
Yesterday I had a client who asked exactly the same question.
I, as Josip said, am a "*****" guy so I should support that:p , but if we want to be fair and keep our professional ethic then we must explain the differences, advantages and disadvantages of each system, then let the client decide.

By "*****" system I mean Direct expansion with "*****".

Here is what I suggest.

1- Initial cost of '*****' and ammonia system is different. For small capacity the initial cost of "*****" is much less than ammonia. But for very large capacities the initial cost of "*****" would be higher. The reason is simple, the number of units that should be installed to give that capacity will be too much and therefore, the cost of everything escalates. Like installation cost and equipment.

I can not give any specific capacity that over that the ammonia system must be considered.

2- Running cost. Again the above discussion is valid. Above a certain capacity, the running cost of the "*****" system will be higher than ammonia, and vis versa.

3- Maintenance and service. For ammonia system there is one engine room with all the equipment there, but for high capacity "*****" systems there will be many engine rooms or set of equipment (in technical terms circuits). So the maintenance of several systems is more time consuming and costly than one.
On the other hand ammonia system has lots of valves which will require maintenance and service.

Other thing is the availability of the required specialists for each system.

4- Ammonia is poisonous and flammable. This part is always puzzled me:confused: . If the products are not packaged then in the event of ammonia leak, the products can not be used anymore. This happens many years ago in the Zürich slaughter house and they had to burn all the meats. Also we had ammonia leak in a Kiwi fruit cold store and ....a lot of damage.

For big capacities, I always suggest that :
pay a small fee for both systems initial design (not so in detail) so that the consultants can estimate the initial and running cost for you.
This will be the basis of your decision.

I would appreciate any expert comments on this.

Thanks
LANA

[Josip]

Hi, Peter_1 :)


What size do you have in mind?
What's 1500 MT and 2000 MT capacity?
What is 300 sku?

Whatever you want to build, insist that a system is installed with an as low as possible condensing temperature.
Can you use warm/hot water in your business?
What's the average temperature in winter and summer in your country?

Metric ton = 1000 kg = http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FTon&ei=UMVCRpn5MpiYnQPKwPT5Dg&usg=AFrqEzfa_a01Kau5L2CGx0p9QXWGn-QtEg&sig2=8xdg2mn8vWkKkSPOS_08JA


SKU = http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FStock_Keeping_Unit&ei=fsRCRuOqHqiqnQP10Kz3Dg&usg=AFrqEzeTWGK4yhEPYxoqMpEw9_q3-4gRLw&sig2=RD1oiMruibiKlZtb4qj5YA

Not an item important for us Peter;)

Best regards, Josip :)

[Josip]

3- Maintenance and service. For ammonia system there is one engine room with all the equipment there, but for high capacity "*****" systems there will be many engine rooms or set of equipment (in technical terms circuits). So the maintenance of several systems is more time consuming and costly than one.
On the other hand ammonia system has lots of valves which will require maintenance and service.

Other thing is the availability of the required specialists for each system.

4- Ammonia is poisonous and flammable. This part is always puzzled me:confused: . If the products are not packaged then in the event of ammonia leak, the products can not be used anymore. This happens many years ago in the Zürich slaughter house and they had to burn all the meats. Also we had ammonia leak in a Kiwi fruit cold store and ....a lot of damage.

Thanks
LANA

Just two comments;)

-why you need many engine rooms for ***** installation:confused:

-there is NO SAFE refrigerant!!!

Best regards, Josip :)

[lana]

Hi Josip,


Thanks for your comments.

Maybe I didn't explain well. I mean there is a unit for each room. These units can be in one engine room or at different places as the piping allows.



-there is NO SAFE refrigerant!!!



I agree;) .

Thanks

[gaz]

Josip,

Thanks for the great links.

By the way, 1 very important question - I just realised my warehouse frontage will be facing west, which means the loading/unloading dock will be facing the afternoon sun.

Of course it is not ideal, but will it be a barrier or huge disadvantage?

Any advice guys on above?

Secondly, is there any template or calculator available to calculate storage cost per pallet or per mt?

With that, then comparison between public warehouse and self own becomes easier.

Thanks.

[gaz]

What size do you have in mind?
What's 1500 MT and 2000 MT capacity?
What is 300 sku?

Whatever you want to build, insist that a system is installed with an as low as possible condensing temperature.
Can you use warm/hot water in your business?
What's the average temperature in winter and summer in your country?

Hi Peter,

I think Josip was kind enough to explain the first 2.

Why build a lowest possible condensing temperature? What's the advantage? And of course disadvantage? And from cost point of view - sounds higher, right?

I do not see why warm/hot water is prohibited. To explain more clearly, my company imports and distribute food products of all varieties. Sort of like Sysco but obviously no where near their figures. Pure distribution with some value added services such as portion control etc.

Peter, I am from Malaysia and only 1 weather that is HOT and HUMID. We're looking at 30 and above degrees celcius all year round.

Thanks and look forward to your advice

[lana]

By the way, 1 very important question - I just realised my warehouse frontage will be facing west, which means the loading/unloading dock will be facing the afternoon sun.

Of course it is not ideal, but will it be a barrier or huge disadvantage?

This will add to the cooling load requirements and not a big deal. If the insulation is of good quality and installed properly then no problem.



Secondly, is there any template or calculator available to calculate storage cost per pallet or per mt?



NO. that 's the consultant's job to estimate the total cost after design.

Good luck
LANA

[gaz]

Hi everybody,

By "*****" system I mean Direct expansion with "*****".

Here is what I suggest.

1- Initial cost of '*****' and ammonia system is different. For small capacity the initial cost of "*****" is much less than ammonia. But for very large capacities the initial cost of "*****" would be higher. The reason is simple, the number of units that should be installed to give that capacity will be too much and therefore, the cost of everything escalates. Like installation cost and equipment.

I can not give any specific capacity that over that the ammonia system must be considered.

2- Running cost. Again the above discussion is valid. Above a certain capacity, the running cost of the "*****" system will be higher than ammonia, and vis versa.

3- Maintenance and service. For ammonia system there is one engine room with all the equipment there, but for high capacity "*****" systems there will be many engine rooms or set of equipment (in technical terms circuits). So the maintenance of several systems is more time consuming and costly than one.
On the other hand ammonia system has lots of valves which will require maintenance and service.

Other thing is the availability of the required specialists for each system.

4- Ammonia is poisonous and flammable. This part is always puzzled me:confused: . If the products are not packaged then in the event of ammonia leak, the products can not be used anymore. This happens many years ago in the Zürich slaughter house and they had to burn all the meats. Also we had ammonia leak in a Kiwi fruit cold store and ....a lot of damage.


Thanks
LANA

Lana, thanks for your insight.

Looking at the above pointers, basically what you are saying are:

1) ammonia has cheaper 1 time implementation cost (subject to certain sizes which i think I fall under anyway)

2) ammonia has a cheaper maintenance cost (unless not many specialist around that region)

3) what we know is ammonia is more efficient and consumes less energy and will save cost over long term

In summary, the only reason why people choose ***** or avoid Ammonia is because of the potential conseqeunces from a leakage?

[gaz]

NO. that 's the consultant's job to estimate the total cost after design.

Good luck
LANA

That's not what I meant.

I already roughly know the cost of my entire new warehouse.

I believe there must be a template or a way to calculate my storage cost per pallet or per mt if I do indeed build the warehouse?

thanks

[lana]

1) ammonia has cheaper 1 time implementation cost (subject to certain sizes which i think I fall under anyway)

2) ammonia has a cheaper maintenance cost (unless not many specialist around that region)

3) what we know is ammonia is more efficient and consumes less energy and will save cost over long term


There are no absolute answers to these. All depends on the size of the system, the complexity of design and other factors.
As of ammonia is more efficient, there is no question. I think it is not comparable to "*****s". It's thermo physical characteristics are unique and the best.


In summary, the only reason why people choose ***** or avoid Ammonia is because of the potential conseqeunces from a leakage?

Not necessarily, sometimes the cost is the issue.

[gaz]

In freezer are you going to keep ice cream? Anyhow here you must use direct cooling system.

For chiller and A/C area is better to use indirect system with enough capacity for production area/room later on. Did you think about FIFO system for dairy products -chiller room/s and for A/C too?

What about capacity for A/C room (chocolate, sugar, salt, rice, flour, candy -wafers, caned goods) ?

4 big rooms (freezer room, diary-meat chiller room, A/C room) or maybe couple of smaller rooms

Handling (receiving/delivery) area can be quite specific (unloading/loading ramps for big or small trucks, fast doors, number of fork lifts, etc.. ) but you know daily traffic in tons, or number of daily trucks in/out...anyhow must be discussed well.


Josip,

No ice-cream. Mostly meat and other frozen food stuffs.

What is direct/indirect cooling system? and benefits/drawbacks?

In food we always try to practice FIFO. But I think what you are saying is incorporating it into the design, is it? Anywhere I can find more details?

Right now looking at 2 or 3 freezers and 1 chiller.

Question - where should I put the loose goods, or products that are picked and less than full carton? Should I have a small room to allocate this or just have a after pick area in the big freezer?

Right now, I am also torn between 2 designs.

1) unloading/loading bay does not have refrigeration. upon unloading, truck will move straight into ante/chiller and then freezer.

2) unloading/loading bay act as both ante and chiller where trucks part right to the door. And from there, into the freezer from ante/chiller.

Obviously, I am looking from cost perspective but my technical knowledge or experience is not good enough for me to assess cost/long term benefits ratio properly. I would not want to cut any cost that will bring more drawbacks in future.

Thanks.

[lana]

That's not what I meant.

I already roughly know the cost of my entire new warehouse.

I believe there must be a template or a way to calculate my storage cost per pallet or per mt if I do indeed build the warehouse?

thanks

OK, I don't understand you then.
Is this correct : You need to estimate that for each Ton of product how much you have to pay to store it?
If this is correct then there are some factors you have to include.
1- The initial cost you spent for the entire warehouse. Then you choose a pay back time. Estimate the total tonnage that would be stored for that time. Then you will know the initial cost for each ton.
2- Running cost: Electricity, maintenance, Service, Workers,.... (calculated for each Ton).

If you add these figures then this should be the cost for each ton. But it is difficult to do because you have to assume so many things.

Cheers

[gaz]

Not necessarily, sometimes the cost is the issue.

Lana - cost = 1 or 2?

1) one time setup cost
2) longer term cost (energy, maintenance, cost of refrigerant etc?)

[lana]

Lana - cost = 1 or 2?

1) one time setup cost
2) longer term cost (energy, maintenance, cost of refrigerant etc?)

Could be both.

[Peter_1]

The lower you can condens, the lower your running cost and this can give you huge benefits, especially in your hot country.
Water is a very good storage device and makes it easier to condens low. You then can use this heated water.

A rough calculation: if I count 200 tons and meat = +/- 700 kg to 1 ton/palet, then this is 200 to 250 pallets.
1 pallet +/- 1 m³, so 250 m³.
This is a freezer of +/- 30 x 20 x 4 m.

We have a client wit a freezer of +/- this dimenions but the pick and place happens mostly in the freezer (the cold chain may not be broken, at least here in Belgium)
Same for the chiller, pick and place in the room.

Don't forget that the initial install cost for an NH3 is much higher then a DX system.
You can use the soil under the freezer isolation to subcool your liquid. You need anyhow a heating system. This heating is then for free and it will give you big savings.

[Josip]

Hi, Gaz :)


Any advice guys on above?

Secondly, is there any template or calculator available to calculate storage cost per pallet or per mt?

With that, then comparison between public warehouse and self own becomes easier.

Thanks.

As per my humble knowledge people use to build cold stores and rent them to make profit. There is not other way to preserve food and every day more and more.

No need comparison;) just try to make a good facility (maybe with bigger initial cost but low running costs, environment friendly) and try to run it for many years:)

Best regards, Josip

[Josip]

Hi, Gaz :)


Josip,

No ice-cream. Mostly meat and other frozen food stuffs.

What is direct/indirect cooling system? and benefits/drawbacks?

In food we always try to practice FIFO. But I think what you are saying is incorporating it into the design, is it? Anywhere I can find more details?

Right now looking at 2 or 3 freezers and 1 chiller.

Question - where should I put the loose goods, or products that are picked and less than full carton? Should I have a small room to allocate this or just have a after pick area in the big freezer?

Right now, I am also torn between 2 designs.

1) unloading/loading bay does not have refrigeration. upon unloading, truck will move straight into ante/chiller and then freezer.

2) unloading/loading bay act as both ante and chiller where trucks part right to the door. And from there, into the freezer from ante/chiller.

Obviously, I am looking from cost perspective but my technical knowledge or experience is not good enough for me to assess cost/long term benefits ratio properly. I would not want to cut any cost that will bring more drawbacks in future.

Thanks.

Where to start :confused:

-direct cooling is when you use refrigerant in your evaporators within cold room - this is "must" for low temperature rooms below -18C

- indirect cooling is when you use primary refrigerant ammonia/***** to cool down glycol (we call that primary refrigeration circuit) and then you pump cooled glycol through your room coolers to cool your goods - applicable for your chillers and for A/C rooms.

Benefits of indirect cooling are: less refrigerant in primary circuit, less valves, connections i.e. less places for possible leaks, more safe.

Drawbacks: little bit higher installation and running costs due to double cooling circuits.

Of course, you are going to build a new cold store why not incorporate this in design:confused:

About FIFO racks and systems you can use Google just write FIFO and enjoy:D

Another question: what about control of goods: in, out, on stock, to order due to minimum on stock etc....(with barcode reader/writer)?

Loose goods, maybe you can use one separate area in one room for all, but due to hygienic reasons maybe is better to use a separate room this is a must in meat industry for "problematic/suspicious" quality meat.


Right now, I am also torn between 2 designs.

1) unloading/loading bay does not have refrigeration. upon unloading, truck will move straight into ante/chiller and then freezer.

2) unloading/loading bay act as both ante and chiller where trucks part right to the door. And from there, into the freezer from ante/chiller.

Why torn:confused: you need only one and good solution (ok maybe I do not understand this, can you post some architectural scheme of your cold store)

You are living in hot and humid area...your truck bay and manipulation area must be of special design to reduce penetration of hot and humid air and increasing your refrigeration load:eek:

and here is your answer:


Obviously, I am looking from cost perspective but my technical knowledge or experience is not good enough for me to assess cost/long term benefits ratio properly. I would not want to cut any cost that will bring more drawbacks in future.

Best regards, Josip :)

[US Iceman]

I would recommend the loading/unloading docks be refrigerated for this reason: Any time the doors are open to the coolers or freezers the warm moist air flows into those rooms also. When this happens the evaporators in those rooms pick up the water as a frost on the evaporators. This is an expensive way to dehumidify the air.

If you keep the docks at about 35°F (1.6°C) to 45°F (7.2°C) this will remove a large percentage of the moisture as a liquid on the coils in the dock area. These evaporators should be blowing air towards the dock doors.

Inside of the coolers or freezers DO NOT install evaporators over a door from outside. These collect a lot of frost and water and make a mess!

I believe an ammonia system using a liquid overfeed will provide you with the best operating economy. It may cost more initially, but the energy savings help you to increase your profits.

I would also suggest two evaporating temperatures. One for the freezers and one for the coolers & dock evaporators.

And, a good condensing temperature to use is 90°F (32.2°C). This increases the cost of the evaporative condenser, but also decreases the energy use during the warm months.

You should also investigate how you will be charged for electricity. If you have cheaper power during the night hours you may be able to save money. These power charges are usually referred to ON-Peak and OFF-Peak. ON-Peak hours are during the early morning to late afternoon. Your utility can advise you on this.

Be careful selecting compressors. If you use large screw compressors then are inefficient when the operate at reduced capacity. Reciprocating compressors are very good to fix this.

Also, use hot gas defrost. It's cheaper to operate than electric defrost.

[gaz]

The lower you can condens, the lower your running cost and this can give you huge benefits, especially in your hot country.
Water is a very good storage device and makes it easier to condens low. You then can use this heated water.

A rough calculation: if I count 200 tons and meat = +/- 700 kg to 1 ton/palet, then this is 200 to 250 pallets.
1 pallet +/- 1 m³, so 250 m³.
This is a freezer of +/- 30 x 20 x 4 m.

We have a client wit a freezer of +/- this dimenions but the pick and place happens mostly in the freezer (the cold chain may not be broken, at least here in Belgium)
Same for the chiller, pick and place in the room.



Peter,

Apologize if I have been clear enough.

Total warehouse = 2000 tonness

Freezer = 1200 - 1500 tonnes

Chiller (1-4 celcius) = 200 tonnes

Dry (room temp.) = 200-300 tonnes

Would help if you can recalculate. Thanks :)

So with the storage capacity above,

1) lowest condensation possible solution still viable and works?

In this method you propose - using hot water that will result in the lowest condensation temperature - what is the technology or system called?

Is this safe? Is this industry practice and considered a best practice?

2) pick and place still in each product's original storage room?

[gaz]

This will add to the cooling load requirements and not a big deal. If the insulation is of good quality and installed properly then no problem.

LANA


Lana,

Adding to cooling load requirement = higher cost? Or you are saying as long as they do a good job, it will be nothing on top?

[gaz]

Hi, Gaz :)

As per my humble knowledge people use to build cold stores and rent them to make profit. There is not other way to preserve food and every day more and more.

No need comparison;) just try to make a good facility (maybe with bigger initial cost but low running costs, environment friendly) and try to run it for many years:)

Best regards, Josip

Josip,

It's going to cost quite some amount, so I have to be sure. Long term capital and real estate gain of course are there.

The only thing unsure is whether I can do it as efficient as the public warehouses, hence the need to calculate cost per storage per tonne to compare.

[gaz]

[quote=Peter_1;66845]

We have a client wit a freezer of +/- this dimenions but the pick and place happens mostly in the freezer (the cold chain may not be broken, at least here in Belgium)
Same for the chiller, pick and place in the room.

quote]

in this method, your client reserve some space for the fork truck to place pallet from racks in order for the staff to pick and then what do they do with the rest of the pallet? leave it there? or do they put back the pallet into the original rack (less picked amount)?

[lana]

Lana,

Adding to cooling load requirement = higher cost? Or you are saying as long as they do a good job, it will be nothing on top?

Hi gaz,

It really depends on the amount of the load. If it is too much then definitely will effect the equipment size and therefore, higher cost. But if it is a reasonable value which is covered by the calculation safety factor then no problem.

If the insulation is of good quality and also installed properly then everything would be OK. But if it is not ,then it will add to the equipment size and also running cost.

Cheers

[Andy]

The lower you can condens, the lower your running You can use the soil under the freezer isolation to subcool your liquid. You need anyhow a heating system. This heating is then for free and it will give you big savings.

Now that is a smart idea. Put the liquid off the condenser thru a heat exchanger cooled by a glycol loop thru the ground under the cold store and you have an very effective subcooler and free heat to stop under floor frost heave.

Kind Regards Andy:)

[gaz]

Hi, Gaz :)

Another question: what about control of goods: in, out, on stock, to order due to minimum on stock etc....(with barcode reader/writer)?

Loose goods, maybe you can use one separate area in one room for all, but due to hygienic reasons maybe is better to use a separate room this is a must in meat industry for "problematic/suspicious" quality meat.

Why torn:confused: you need only one and good solution (ok maybe I do not understand this, can you post some architectural scheme of your cold store)

You are living in hot and humid area...your truck bay and manipulation area must be of special design to reduce penetration of hot and humid air and increasing your refrigeration load:eek:

Best regards, Josip :)

Josip,

1) Initially it will be manual and then once the system is implemented, bar code scanning in but not out. Out will probably still be manual.

2) Have thought about using separate rooms, but then I will have 3 separate rooms with different temperature - could be a bit of a nightmare?

For delivery no problem - just chuck all the orders in the loading bay after picking and load.

3) torn between below:

Truck --> Unload/loading dock (non refrigerated) --> ante/chiller (2-4 degrees celcius) --> freezer
Truck --> Unload/loading dock/ante/chiller (2-4 degrees) --> freezerOption 1 save money on unloading/loading dock as the chiller i need is not that big.

[gaz]

I would recommend the loading/unloading docks be refrigerated for this reason: Any time the doors are open to the coolers or freezers the warm moist air flows into those rooms also. When this happens the evaporators in those rooms pick up the water as a frost on the evaporators. This is an expensive way to dehumidify the air.

If you keep the docks at about 35°F (1.6°C) to 45°F (7.2°C) this will remove a large percentage of the moisture as a liquid on the coils in the dock area. These evaporators should be blowing air towards the dock doors.

I believe an ammonia system using a liquid overfeed will provide you with the best operating economy. It may cost more initially, but the energy savings help you to increase your profits.

I would also suggest two evaporating temperatures. One for the freezers and one for the coolers & dock evaporators.

And, a good condensing temperature to use is 90°F (32.2°C). This increases the cost of the evaporative condenser, but also decreases the energy use during the warm months.

Be careful selecting compressors. If you use large screw compressors then are inefficient when the operate at reduced capacity. Reciprocating compressors are very good to fix this.

Also, use hot gas defrost. It's cheaper to operate than electric defrost.

Iceman,

1) If docks are refrigerated from 1.6-7°C as per your suggestion, when dock doors are open for incoming truck, wouldn't that be bad for the refrigerated dock?

As 1 of the option is to have the dock double up as chiller to put my dairy products (2-6 °C).

2) Using Ammonia vs ***** is still an unresolved issue for me, partly because I am still considering the effect of Ammonia leakage which means bye bye stocks.

Anyway to overcome this risk?

3) Why 2 evaporating temperate for the different rooms?

4) The 32.2 °C condensing temperature is considered high or low? Reason I am asking = trying to find relation to Peter's suggestion on lowest condensation will be huge advantage

5) in what situation does reduced capacity happens? People are highly recommending me screw compressions for reasons I have to find out honestly.

Thanks.

[gaz]

Guys,

I got this from my supplier's contact in the states.


Generally it comes down to square footage. Ammonia is more cost-effective. If you are 5,000 sq. meters (50,000 square foot) or larger than go with Ammonia. If you are smaller, go with *****. It is more cost-effective due to high cost of Ammonia equipment.

This is really an industry rule of thumb that we use.

Any truth in the above statement?

[US Iceman]

1) If docks are refrigerated from 1.6-7°C as per your suggestion, when dock doors are open for incoming truck, wouldn't that be bad for the refrigerated dock?

As 1 of the option is to have the dock double up as Chiller (http://www.refrigeration-engineer.com/forums/glossary.php?do=viewglossary&term=36) to put my dairy products (2-6 °C).


Several things you need: When a trailer backs up to the dock doors, the back of the trailer is sealed by what we call door seals. They are thick foam pads (a cushion in effect) that seals the back of the trailer to prevent excess hot, moist air from entering the docks.

The purpose of refrigerating the docks is to reduce the amount of moisture that flows into the docks and subsequently the coolers or freezer.

Whenever the outdoor air has a high relative humidity (high moisture content) this adds a significant cooling load to the refrigeration system.

Another concern is to have the trailer temperatures low before the dock doors are opened to the trailer. Empty trailers sitting in the sun get very warm. Their refrigeration units should be started earlier enough to cool them down.

If you use the dock as a staging area for getting product ready to ship, it should be refrigerated to prevent condensation on the product.



2) Using Ammonia vs ***** (http://www.refrigeration-engineer.com/forums/glossary.php?do=viewglossary&term=185) is still an unresolved issue for me, partly because I am still considering the effect of Ammonia leakage which means bye bye stocks.

Anyway to overcome this risk?


You need to use ammonia gas detectors anywhere there is ammonia in piping or other components. Since this refrigerant has a very strong odor, any leak is usually noticed very quickly.;)

Another aspect is the actual installation. I prefer to have all joints welded (either butt weld or socket weld). Threaded joints are dependent on the care of fabrication when the pipe threads are cut and the condition of the cutting dies. Although some flanges are necessary, I would try to keep their use to a minimum.
The system design pressure also plays a part of this. You want the system design pressure (& the pressure relief valves) to be high enough to prevent unintended ammonia releases from occurring if the power goes out during warm weather.

Ammonia leaks and releases are very rare. When they do happen it is usually caused by a person who does not understand the work they are doing, or poor design/installation practices have been used.



3) Why 2 evaporating temperate for the different rooms?


This suggestion is meant to improve the system efficiency and lower the cost of operation. The cost of operation improves if you run the higher temperature loads (coolers and docks) at a higher evaporating temperature.

If you have only one lower evaporating temperature for the freezers (that is also used for the warmer cooling loads) this is more expensive to operate. It might be cheaper to install a single temperature system, but they do cost more to operate.

You have to look at your various air temperature requirements and see if you can find some average evaporating temperature for the refrigerant. I normally see at least two average evaporating temperatures that can be used.



4) The 32.2 °C condensing temperature is considered high or low? Reason I am asking = trying to find relation to Peter's suggestion on lowest condensation will be huge advantage.


Peter is 100% correct. You do want to keep the condensing temperature as low as possible. Most normal design parameters for ammonia condensing temperature is 35°C (95°F).

In the warm weather when the relative humidity is high you have some limits on what you can do. The outdoor humidity and the total condenser capacity restrict how low you can condense in the summer.
(I am assuming your system will use evaporative condensers)

My suggestion of using 32.2°C for the design condensing temperature was intended for the summer operation as a reasonable selection method to lower operating costs during the summer. You can increase the capacity/size of the condensers but the actual installation costs become higher than what you might save, if the larger condensers are used.

The key to this is to allow the discharge pressure to operate at the lowest possible level during any weather condition.



5) in what situation does reduced capacity happens? People are highly recommending me screw compressions for reasons I have to find out honestly.


The types and sizes of the compressor to be installed is based on three things: total capacity required, changes in cooling loads, and judgement.

If the total cooling loads can decrease by 50% (or more) for any reason you need to investigate the different times and reasons they do so.

A screw compressor does not operate efficiently at low loads, while a reciprocating compressor does.

You need a profile of the load changes so the compressors can be selected to provide the best operating efficiency at ANY operating condition.

Most people will see a large cooling load and automatically select several large screw compressors to meet the 100% cooling load requirements. While that provides the required capacity, it does not usually offer any advantage to lowering or minimizing operating costs.

[US Iceman]

Generally it comes down to square footage. Ammonia is more cost-effective. If you are 5,000 sq. meters (50,000 square foot) or larger than go with Ammonia. If you are smaller, go with ***** (http://www.refrigeration-engineer.com/forums/glossary.php?do=viewglossary&term=185). It is more cost-effective due to high cost of Ammonia equipment.

This is really an industry rule of thumb that we use.

Any truth in the above statement?


Some. You have to remember this is based on some rules-of-thumb. These statements are based on expected installation costs and initial equipment costs., but do not necessarily reflect the total operating costs.

The costs depends on the above factors, plus the physical size of the facility and the total cooling load required.

You may also hear another general statement that direct expansion systems are cheaper to install than liquid overfeed systems. Again, this is a general statement and not always true for a fairly large system capacity.

Any of my suggestions so far are based on what is normally seen here in the US and reflect the concern for minimizing operating and installed costs.

[Josip]

Hi, Gaz :)


Josip,

1) Initially it will be manual and then once the system is implemented, bar code scanning in but not out. Out will probably still be manual.
2) Have thought about using separate rooms, but then I will have 3 separate rooms with different temperature - could be a bit of a nightmare?
For delivery no problem - just chuck all the orders in the loading bay after picking and load.
3) torn between below:
Truck --> Unload/loading dock (non refrigerated) --> ante/chiller (2-4 degrees celcius) --> freezer
Truck --> Unload/loading dock/ante/chiller (2-4 degrees) --> freezerOption 1 save money on unloading/loading dock as the chiller i need is not that big.

1. it is ok, if you find good store keepers no problem ;), you can run in that way. Later on when budget permits go to upgrade:D.

2. you are probably right, maybe better to use one separate place in each room (near the door to be always visible:cool:) to put loose goods (just find a person to take a good care about;)). Much better then to have additional rooms with separate temp.

3. Regarding utility of goods per day (in-out) 10%, 20%, 30% or more I will suggest you to make a big/bigger handling area and definitely cooled...to take care about your freezers not about chiller room

To explain this: if you have 2000MT cold store and daily utility only 10% what makes 200 tons think about how fast you can load/unload that.

In my opinion it is much better to incorporate dock bay in handling area. All freezer rooms you must equipped with double automatic fast doors with plastic or/and air curtains..making a small ante room...

Anyhow take a look at those links:

http://www.statusfluidpower.com/catalogue/dock_levellers.php
http://www.geapl.net/inflatableds.html
http://www.buildingdesign.co.uk/arch-3/industrial-doors/industrial-doors-uk.htm
http://www.jsaircurtains.com/products/SEURLF/ASP/SFS/PID.175/SFE/details.htm

Of course for more info use Google

Best regards, Josip :)

[Josip]

Hi, Gaz :)


Guys,

I got this from my supplier's contact in the states.


Generally it comes down to square footage. Ammonia is more cost-effective. If you are 5,000 sq. meters (50,000 square foot) or larger than go with Ammonia. If you are smaller, go with *****. It is more cost-effective due to high cost of Ammonia equipment.

This is really an industry rule of thumb that we use.

Any truth in the above statement?


The truth is sometimes somewhere in the middle....


Some. You have to remember this is based on some rules-of-thumb. These statements are based on expected installation costs and initial equipment costs., but do not necessarily reflect the total operating costs.

Maybe to check some more sources:

http://www.google.com/url?sa=t&ct=res&cd=3&url=http%3A%2F%2Fwww.iifiir.org%2Fen%2Fdoc%2F1055.pdf&ei=KO9GRv_kBqKinQPZtrgf&usg=AFrqEzcOCL9gLoqMtc-CBJkd_qQy7TWZMA&sig2=e4PpBY66AN5pXDFAazpIgA
http://www.google.com/url?sa=t&ct=res&cd=5&url=http%3A%2F%2Fwww.munters.co.kr%2Flink%2FFog%2520condenc.pdf&ei=xfVGRuTfMpuWnQOs07gv&usg=AFrqEzc2e6WRyKQrWcugyujxF_Zz5VE5Sw&sig2=2KuvjMzYsP7-jkfkDh838g
http://www.google.com/url?sa=t&ct=res&cd=6&url=http%3A%2F%2Fwww.devonline.gov.uk%2Findex%2Finformation_and_services%2Fenvironmental_health%2Feh-healthandsafety-intro%2Feh-hs-guidance%2Feh-hs-coldstore.htm&ei=xfVGRuTfMpuWnQOs07gv&usg=AFrqEzfZlqo_uEMBC0ZlN4wz8IMf74IJgw&sig2=taMrKsOdJgNf6SXPXBdpcQ
http://www.celsius-projects.com/index.php?page=6
http://www.fjb.co.uk/PublicationsFrameset.htm

A lot to read...and maybe to ask...
Best regards, Josip :)

[US Iceman]

Gaz,

Another source of information on owning and operatig costs may be available from the International Association of Refrigerated Warehouses.

http://www.iarw.org/index.asp

I belelive they have a lot of information that can be beneficial to you, however, I think you have to be a member to receive some of it.

A direct inquiry from you may be able to provide some of the data you are looking for.

[Josip]

Hi, Gaz :)


Lana, thanks for your insight.

Looking at the above pointers, basically what you are saying are:

1) ammonia has cheaper 1 time implementation cost (subject to certain sizes which i think I fall under anyway)

2) ammonia has a cheaper maintenance cost (unless not many specialist around that region)

3) what we know is ammonia is more efficient and consumes less energy and will save cost over long term

In summary, the only reason why people choose ***** or avoid Ammonia is because of the potential conseqeunces from a leakage?

Please read this:

http://www.refrigeration-engineer.com/forums/showthread.php?goto=newpost&t=7981

Best regards, Josip :)

[US Iceman]

Josip, that is a good article. That gentleman has been around ammonia systems for a long time.

[Sledge]

I have seen only one major frozen food storage wharehouse, which incorporated stacker cranes, with automatic storage and retrieval systems, stored 50-60,000 pallets. The stacker storage was kept at -20F, standard warehouse storage at -20F, a chiller at 35F, loading dock at 35F(I cant remember dock temp for certain)

They used ammonia for the freezers, and ***** for the loading docks.

The ammonia systems were all floooded evaps, with EPR's.

Loading docks were kept cold for dehumidification.

One consideration is the moisture on the dock floor. Condensation was terrible from hot humid air entering when dock doors opened, condensing on cold floors in dock, very slippery, safety nightmare for fork lifts, never solved.

The floor under the freezer was kept warm by blowing warm air through ducts built into the floor, beneath the concrete. This would be free in a hot country, but in Canada we had to heat the air.

There is a real division between Ammonia and ***** in Canada, I dont know if it is same in your country. They are regulated by 2 different governmental bodies, and technicians are seldom licensed and/or knowledgeable in both systems. It may be harder to get service on Ammonia if people are not available.

It has been a long time since I worked on Ammonia, but I do remember they attempted to use a DX application, through the use of a HP and LP receiver, and a thermosiphen...and it didnt work well at all. I know there was some consideration

[acvr]

I hope someone answer to at least parts of it, I am going to write and try to make the perfect warehouse for my reference and everybody that what’s to make one or use it like a thesis (that is another thing I am doing, killing to birds at the same time J)
I appreciate when the question are answer to put the number so nobody gets lost

1) In my country there’s a huge need of cold especially for food, so I don’t know which area it’s more profit to refrigerate from food and which one has more demand. Knowing this we could know more about the size of the warehouse and its freezers. At these moments we are thinking about 3 freezers of 1500 mt2 and 1 cooling tunnel.
(It could be more or less depending of the research).

2) Why is the ammoniac more dangerous than the *****? I heard that both are toxic? Is it more dangerous because the ammoniac leaks?
Both are toxics the difference its that ammoniac leaks

3) How does the ammoniac alarm or sensors work?
By the strong odor of the ammoniac when its leaking

4) Whats the difference between freezer and chiller?

5) Before connecting the truck to the dock would it help to put a portable refrigerator to cool it down? Why?
Yes, because it helps to avoid loosing cold = energy from the docks and avoid humidity to enter to the docks

6) What’s the difference between direct cooling systems and indirect?
Direct cooling is when you use refrigerant in your evaporators within cold room - this is "must" for low temperature rooms below -18C
Indirect cooling is when you use primary refrigerant ammonia/***** to cool down glycol (we call that primary refrigeration circuit) and then you pump cooled glycol through your room coolers to cool your goods - applicable for your chillers and for A/C rooms.
Benefits of indirect cooling are: less refrigerant in primary circuit, less valves, connections i.e. less places for possible leaks, more safe.
Bad of indirect: little bit higher installation and running costs due to double cooling circuits.
(This info right or something is missing)

7) What is FIFO?

8) What tempeture should be use outside the freezers but in the warehouse?
If you keep the docks at about 35°F (1.6°C) to 45°F (7.2°C) this will remove a large percentage of the moisture as a liquid on the coils in the dock area. These evaporators should be blowing air towards the dock doors.
(This info right or something is missing)

9) Why do we have to unfreeze some process and places?

10) It’s better to use hot gas o electricity to unfreeze?
Hot gas
(This info right or something is missing)

11) If the warehouse its build underground at least part of it would the energy cost would be cheaper?

12) There are 3 kind of freezer? Why? What about pharmaceutics?
One for vegetable, eggs, wood. One for meat, fish and chicken. One for fast food
(This info right or something is missing)

13) Why the doors have to be of rubber and go up and down and not to the sides? Why can’t it be a sliding door or a double door (like the submarines)?

14) Which doors got the best technology and which has the best price and good technology?

15) How the humidity does plays in this game? And what does it affects?

16) Which brands of stock picker truck or pallet truck are consider the best?

17) How much space between stand should leave so the pallet truck can turn around?

18) How could I optimize the space of the freezer, it’s there a free program or some calculus that could help me to put the stands?

19) Which stands are better? Which dimension fit all? Witch materials are good for it?
Dimension that fit all: 1x 1,30x 1,70

20) What’s the perfect height for the freezer?
2002 ASHRAE Refrigeration Handbook: 8.5 to 10.5 m
(This info right or something is missing)

21) How much space should I leave between the boxes (paletas) in the stand that are in the freezer?
a) 5 cm floor to box, the space for the pallet truck to get the box and 5 cm to the roof
b) 5 % of the total volume of the boxes
c) 10cm between the lines of boxes, a 25cm gap from the walls and a 75cm gap between the ceiling panel
(This info right or something is missing)
22) Could I use the cold air of the refrigerate tunnel (when I finish using it) to cold something at the warehouse?

23) What is that about cleaning with ozone water? What for? And why this type of water?
Its for fruits or food that its not completely package to clean them up so they don’t get bad

24) Most of freezers have 100% air, why others need 98% of nitrogen or other component?

25) What’s a panel? How are they build? Which foam its better? How do you hang them from the roof? Why not make a structure from the floor to hold it? Why put on top of the floor panel concrete?
A panel its like a sandwich of 2 metal with a foam inside
26) How does it work freezing by gas at a lot of pressure? Why? Should be more expensive?

27) Does the cold affects to put a RDF system?

28) Is it true that you could say that 1 m2 needs 500 BTU approximate?

29) How much it’s a ton of cold?
30) If somebody has something to add I will appreciate
Thanks for helping in anything you can and helping other people with this question, I will keep in touch, to tell how the project its going, to ask knew things and to a port others things that mite help us all to be better engineers and business men’s and women.
I understand that all this its pretty easy for you guys, so I will be grateful if you could give me a link to read about each of this points

[Peter_1]

7. http://www.audioenglish.net/dictionary/fifo.htm
I've done my part ;)

[icecube51]

29 = 3517Watt or 12500BTU

Ice

[acvr]

thanks peter and icecube

[BoilerBoy]

Meat - 28
produce - 50
ice cream - -20
freezer - -10
docks - 35
cooler - 35
Ammonia all the way. Well maybe 718......