Installation query - Ceiling Mounted Evaporators

[sighmon55]

Please can somebody advise me as to what the industry "norm" is for fixings on ceiling mounted evaporators? I recently became involved in a case whereby a newly installed evaporator (single fan approx 25kg) came loose from it's fixings inside a walk in freezer. The installer had used 4 x .75inch self-tapping screws to ceiling mount. The freezer is standard design - aluminium skin, insulation and then outer skin.

I thought the suggested fixing method was studding?

[chemi-cool]

We use special bolts that holds the evaporator firmly to the ceiling.

[r.bartlett]

Best practice: nylon threaded rod

[monkey spanners]

Generally i like to use either nylon threaded rod on small evaporators and stainless steel on big ones. Something to keep in mind is it needs to be able to hold the evaporator up if it becomes full of ice which could be anything from a few kilos to a few tons.

One of the companies i subbie for has wooden beams built in to the roof panel where the evaporator is going to be sited and uses coach screws. This is because there is often no access to the roof to fit rods in the small shops he specialises in.

It would also be worth checking the manufactures recommendations.

Jon :)

[Tayters]

Nylon studding as Mr B and Monkey suggest.

The nylon is used to alleviate hygiene and corrosion issues I believe. Using 4" screws eh? Well depending on the thickness of insulation the screws may only have gone through 1 skin. If they went through both then best not kneel on the top fixings unless your name is Officer Murphy. Doubt if the coldroom skin is designed (thick enough) to hold that weight anyway. Bad job.

Cheers,

Andy

[sighmon55]

Does anybody know where/if there is any "industry guidelines" on this type of install?

[sighmon55]

I presume this method involves drilling through from topside all the way into the freezer - Certainly seems a secure method equivalent to standard studding.

[Peter_1]

Drilling through the panels will give you cold-bridges.
If you tighten firmly a bolt-through evaporator, you will have a small crater on the roof of the freezer (under the bolt/washer)where the condensed water will collect.
Therefore, the nylon threads like Richard proposed solves this problem.
We mostly slide a small piece of Armaflex over the bolts and glue it.

[sighmon55]

Going back to the original query - I presume using small (.75 inch) self-tappers in this case is a no no?

[Peter_1]

The original installer must attach his units in such a way that they under normal conditions can't fall from the ceiling, whatever method he wants to use for this.
In your case, the evaporator fas fallen from the ceiling under normal conditions, so he failed to accomplish standard, safe requirements.
If this should be a case for The Court, then I should take the install instructions of the manufacturer, measure the predrilled holes in the evaporator, and try to find how much load you can hang on a screw.

[Peter_1]

Something like this http://www.strongtie.com/products/quikdrive/fasteners/general_loadtables.html
or
http://www.tlshield.net/public/documents/112.pdf

[Andy]

Hello Gents:)

In my case I use stainless steel treaded rod up through the ceiling to cross beams suspended from the main building structure, with aramaflex sealed over the rods with silicone.
Small rooms can have the coolers supported by unistrut run above the room wall to wall with treaded rod dropped down through the ceiling. If you space the unistrut off the ceiling panel you can add some armaflex to the rod to stop cold bridging or sweating.

Screws unless stainless rust and break, ceiling panels have no support normally for you to fix anything to:mad:

Kind Regards Andy D

[lowcool]

i use 100mm square plates under the nut and washer with a liberal coating of silicone under the plate and around the threaded rod.good vapour seal and stronger support