Negative Refrigeration Cooling effect

[Kenny Pollin]

Can anyone explain the afore mentioned?

[NoNickName]

It's a mistery to me.... (the game commences, for the usual fee, plus expenses, confidential information, it's in a diary, this is my investigation, not a public inquiry...)

[US Iceman]

Hi Kenny,

You did not provide very much information or related context.

Without any additional background, I would have to say... Heating.

[Kenny Pollin]

Hi, i think i have it covered, i was refering to supermarket refrigeration cabinets i think i now understand that it is the over spill of cooling from the cabinet into the shopfloor, it is a figure that the HVAC engineers then require to size shop heating cooling equipment. Do you understand this to be the answer?

[US Iceman]

Well I have to say that is a new term for me. Have not heard that one before, However, I can see their concern. The store aisles do get cold.

The term is not very intuitive at first glance. It must be one those that are made up to describe a certain effect.

Perhaps one of the supermarket mods will see this and comment.

[Andy]

Hi, i think i have it covered, i was refering to supermarket refrigeration cabinets i think i now understand that it is the over spill of cooling from the cabinet into the shopfloor, it is a figure that the HVAC engineers then require to size shop heating cooling equipment. Do you understand this to be the answer?

Kenny
welcome from N. Ireland

Dairy cabinets are the main problem, well freezers by there nature hold a cold well of air so the spillage is lessprovided the A/C does not blow the air out of them
Rule of thumb would be 30% of your dairy refrigeration capacity is what is taken up by refrigerating the shop air entering the cabinets. It can be more if your cabinets are overstocked, it can be less if using night blinds at night, but then you wouldn't be heating much at night.


We use heat recovery on the refrigeration plant to recovery much of the losses in heating to reheat the shop air.

The best way to heat the cold Isle is underfoor heating. Never let the A/C or ducted heating blow into the cold Isles, it just causes a negative effect, making both your refrigeration and your heating run harder to defeat each other.

Kind Regards Andy

[nh3simman]

I did the aircon design and installation of a big supermarket.

There were many cabinets for dairy, meat... In this particular design, the room load was all cooling and the refrigeration cabinets gave me a potential saving of 40% of the total room load.

In the end, I decided to select for the full cooling load. The reason was because the shop was part of a shopping centre and the chilled water was from central plant. I used a VAV air handler so the air and chilled water flows would be controlled anyway.

But, I had the capacity for the space without the refrigerating cabinets. All I needed was a call from the owners telling me that the "new client" does not have enough cooling. You know how these places shops move around.

For the airconditioning, there is a potential saving. Whether you take the credit depends on the application.

[750 Valve]

Kenny
Never let the A/C or ducted heating blow into the cold Isles, it just causes a negative effect, making both your refrigeration and your heating run harder to defeat each other.

Kind Regards Andy

Wish a major chain over here could get that through there heads Been fighting this issue for a while now. They blow warm unbalanced air behind the cases and out under the kickplates - may be alright if the air velocities were balanced... causes HAVOC when 2 cases put in a corner (90 degree) arrangement or with small aisles.
They used to have the air flow reversed, using the kickplates as the system return air and drawing the cold air from the aisles, controls, electricals and drains get VERY dirty drawing air from floor level, imagine the return air ducts!