calculation question

[jayjay]

I have a walk freezer ( 0 degrees F) that a tenent wants to add about 1000 lbs of pasta to everyday. The pasta is about 60 degrees F. Will this have a big effect on my cost to operate the units? How can I figure what this will add to the electric bill? He will also be opening the door three times a day. Is there a simple way to figure this? I'm not a refrige tech so be nice and make it simple.
Thanks

[NoNickName]

Is pasta warm and moist? What weight of water in percentage?
But mainly: why for god's sake you want to freeze pasta?

[lana]

But mainly: why for god's sake you want to freeze pasta?

I just love your accent :D :D :D :D

Anyway, Dear JayJay,
This job requires good cooling load calculation. In that you have to consider the loading per day and the entering temp., and many other parameters which you may know.
After you have the cooling load then you can select proper equipment to satisfy this load.
Good Luck.
Cheers:)

[chillin out]

How can I figure what this will add to the electric bill?
You don't have to, why don't you have a electric meter installed to the property?

Chillin:) :)

[Electrocoolman]

You don't have to, why don't you have a electric meter installed to the property?

Chillin:) :)

Agreed!

Jay....You also need to bear in mind that some "Freezers" are NOT designed to freeze, but only designed to STORE pre-frozen goods.

ECM

[Dan]

I am going to wing it here. Lana and no Nick, feel free to rip me up.:)

You will have what we call a sensible load... the amount of heat you need to remove to bring the pasta down to the freezing point, then you will have what we call the latent load which is the amount of heat it requires to freeze the product, and then you will have another latent load which is how much heat is required to bring the pasta to the storage temperature.

The books I have don't list pasta. I would assume that it is already dried and has less than 20% moisture conent.

Thus 1000 lbs X .2 = the equivalent of 200 lbs of water. It takes 200 X 28 deg F = 5,600 Btu's to lower the temperature from 60 deg F to 32 deg F. Water requires 144 btu's to freeze each pound, so we have .2 X 144 X 1,000 = 28,800 btu's. And add the load of lowering the frozen product temperature to 0 deg F. .5 X .2 X 1000 = 100 btu's. Thus you have a load of 5,600 + 28,800 + 100 = 34,500 btu's.

Let's say you have a 10 X10 freezer. You already have a unit sized to remove about 8,000 btu/hr or approximately 192,200 btu per 24 hour period. Your pasta load will increase your electric bill for the freezer approximately 20%. This equates to at least 10 kw. At $0.10 per kw times 8,760 hours in a year X .7 cycle duty factor (compressor run time), you have at least an added cost of about $6,000.00 per year, or $500.00 a month.

http://www.professionalpasta.it/dir_3/3_techno/3_dry_/chap_3_1.htm#formulas1

This web site gives me the impression that I am assuming about double the moisture content of the pasta. In which case, you are looking at an increase in electric consumption of $250.00 or so per month.

[lana]

I am going to wing it here. Lana and no Nick, feel free to rip me up.:)
.

Hi Dan,
You are completely right. It is all down to cooling load calculation.
Cheers:)

[NoNickName]

I still miss the point in freezing pasta. Pasta is dried and packaged, never frozen unless already cooked.

[jayjay]

Well thanks for all the responce's I'll try and respond to all,
First off he makes pasta and freezes it to sell. Thats his deal, Its much better fresh but hey???
I'm trying to install meters its complecated with the local utility and space for meters etc.
I believe this freezer was designed for pre frozen food it can bearly do that. Thats what I'm trying to explain to these guys that the unit is struggling to maintain temp.
Thanks Dan thats exactly what I was looking for. Thanks again.

[nh3simman]

Is pasta warm and moist? What weight of water in percentage?
But mainly: why for god's sake you want to freeze pasta?

Forget about the cooling problem, we need to know about this pasta.

[NoNickName]

I'll never help anybody wanting to freeze pasta. :-) Excuse me.

[jayjay]

O.K. The bulk of the pasta is raviollis. The taste fine when the are frozen then you just throw them in boiling water for a few minutes and its all good. They are with out a doubt better fresh. I have to be there wendsdays for that. Then you can almost just pour boiling water over them and eat it up.
Any way this seems a little off track for this forum but seems like some people were losing sleep over frozen pasta.
Thanks for your help (and a few laughs)

[ylaw]

Hi Dan,
I am very interested in your formulae.
Is there any links where I can find out more of these kinds? especially in SI unit? Thanks

[Dan]

Ylaw, why don't you try out this free software from Keeprite.
http://www.keepriterefrigeration.com/calcrite/RTcalc1.htm

[BigJon3475]

"To make one pound of pasta, you need 2 cups of unbleached flour, 3 large eggs, and a 1/2 teaspoon of salt."

Specific Heat:

Eggs: .76Btu/lb/ºF
Flour: ..38Btu/lb/ºF
Salt:????

Salt lowers the specific heat of reg water from 1.0 Btu/lb/ºF to Salt Water which has a specific heat of .94Btu/lb/ºF....

You should be able to figure volumes of what he uses for his ingredients and figure out the specific heat of recipe for pasta......That's if he'll give it to you lol....

wet pasta just makes it that much harder by the extra lb's that is added by water weight....That's his main problem I believe...I'd..........walk away and go get some NY pizza and think over how to sell a better freezer for his application. :D But you'll need to prrof as to why.

[Sledge]

I still miss the point in freezing pasta. Pasta is dried and packaged, never frozen unless already cooked.


When you buy pasta from a commercial, mega corporation pasta maker, it comes as dehydrated, virtually tasteless sticks.
When you buy home made quality pasta from a small specialty pasta maker, usually selling to high quality restaurants or boutique type food markets, it is made and then frozen, to be cooked within a few weeks at the most. It is usually about 5 times the cost, but it tastes way better.

Married 20 years to an Italian chef