Refrigeration Machinery Room?

[klarenbeek]

We have a locally owned Whole Foods type grocery store doing a remodel and expansion, including a complete upgrade of refrigeration systems. They are replacing several current split systems with the typical compressors on the roof with two rack systems, one for refrigerating and one for freezers. Each system will have 250-300 pounds of R-449A. The compressors and receiver tanks are going in a back storage/freight dock area consisting of about 7000 cubic feet. Based on that, the refrigerant charts bump that area into requiring it to be a machinery room. To avoid that, the contractor is proposing not installing the double swing doors in a doorway connecting that back area to the main store to allow the store space to be included in the calculations because they are now connected by a permanent opening:

1104.4 Volume calculations. Volume calculations shall be in
accordance with Sections 1104.4.1 through 1104.4.3.
1104.4.1 Noncommunicating spaces. Where the refrigerant-
containing parts of a system are located in one or more
spaces that do not communicate through permanent openings
or HVAC ducts, the volume of the smallest, enclosed
occupied space shall be used to determine the permissible
quantity of refrigerant in the system.

I'm assuming the doorway would meet the requirement for a permanent opening?

They also asked if they could change the doors to saloon style doors so there's still some sort of barrier between customer areas and the back area. There would still be 25 to 35 square feet of opening total above and below the doors.

 

[Mech]

From 2015 IBC 1006.2.2.2 Refrigeration Machinery Rooms.

. . . Doors shall be tight fitting and self closing.

 

[cda]

Refrigeration Machinery Room​

Is there a definition ??!

or quantity level when this kicks in???

 

[Mech]

Not real helpful, but here is the definition from 2015 IMC.

202 Machinery Room. A room meeting prescribed safety requirements and in which refrigeration systems or components thereof are located (see Sections 1105 and 1106).

 

[cda]

We have a locally owned Whole Foods type grocery store doing a remodel and expansion, including a complete upgrade of refrigeration systems. They are replacing several current split systems with the typical compressors on the roof with two rack systems, one for refrigerating and one for freezers. Each system will have 250-300 pounds of R-449A. The compressors and receiver tanks are going in a back storage/freight dock area consisting of about 7000 cubic feet. Based on that, the refrigerant charts bump that area into requiring it to be a machinery room. To avoid that, the contractor is proposing not installing the double swing doors in a doorway connecting that back area to the main store to allow the store space to be included in the calculations because they are now connected by a permanent opening:

1104.4 Volume calculations. Volume calculations shall be in
accordance with Sections 1104.4.1 through 1104.4.3.
1104.4.1 Noncommunicating spaces. Where the refrigerant-
containing parts of a system are located in one or more
spaces that do not communicate through permanent openings
or HVAC ducts, the volume of the smallest, enclosed
occupied space shall be used to determine the permissible
quantity of refrigerant in the system.

I'm assuming the doorway would meet the requirement for a permanent opening?

They also asked if they could change the doors to saloon style doors so there's still some sort of barrier between customer areas and the back area. There would still be 25 to 35 square feet of opening total above and below the doors.

SO A1

So how many pounds per 1000 cubic feet???

 

[klarenbeek]

Table 1103.1 has R 449A at 23 pounds per 1000 cubic feet allowed. At 7000 cubic feet, that allows 161 pounds before machinery room requirements kick in. What they want to do is have an open doorway between the back area where the equipment is and the main store, so then they can also include the volume of the store to give them the needed volume to not require a machinery room. Unfortunately the project square footage falls below the level where stamped drawings are required for mechanical. The refrigeration plan was not the most detailed to say the least. To throw another wrench into it the area where the compressors are located is also their incoming freight area.

I guess my question is what qualifies as a permanent opening in 1104.4 to combine adjacent spaces for volume calculations? Would having an open doorway (or mostly open if saloon doors are installed) meet the intent? I've considered using the adjoining spaces criteria from IMC 402.3 as at least something to go by for permanent opening sizing. Gotta love some of these crystal clear statements in the codes!

 

[Paul Sweet]

How can you assure that it will stay open?

 

[klarenbeek]

Original plan was full height double swing doors. They would be removed so it will be a cased opening, either no door or just saloon style doors with at least a couple feet above and below open.

 

[north star]

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Sounds like they are wanting their cake and eat it too !
"Permanent Opening" = cased opening, no doors or other
types of obstructions.

Freight loading \ unloading through a Machinery Room.
Yeah, ...that doesn't have trouble \ problems written all
over it.

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