Spot cooler safe for building?

[miket]

We are looking into cooling a small computer room on the weekend while the building A/C is down. Total load is currently 9000 BTU and will ultimately reach 12000. The room has a supply and return off the main system. The building uses a plenum return.

We are considering two options. The first is a spot cooler with exhaust into the plenum. The second is a 1-ton mini-split.

The spot cooler would cost roughly one-third what the mini-split would; however, our HVAC contractor has raised the issue of potential structural problems to the roof from dumping the heat into the ceiling without the main system running. Our building manager isn't sure it's safe, either.

If we need to install venting, the cost would rapidly approach the mini-split's. We own the building.

Thanks for any comments.

[bku46]

Tell your contractor he full of crap, I have many spot coolers in operation at various sites doing just what you want. Spot coolers are your best option.

[ZeroCool]

They can cause all sorts of problems,in concrete buildings they can heat the slab above on a weekend shut down, if any common returns are nearby the heat can "roll" back into the space, They can put a load on an already taxed air handler for that floor by dumping extra heat, but its only a ton of extra air. People install them and don't maintain and the floats get stuck and flood, or the condesate line, if it pumps, gets bent/kinked.They usually use the air they have cooled for condenser air, so the room goes neg. drawing in outside the room air thats probably 85, or put that crappy second tube to pull the 100 degree air you are discharging back in. There are reasons most class a buildings only allow them for temp. situations i.e., if a tower goes down, system maint., etc. If you plan on staying any length of time go for the ductless mini, or a Liebert M/M, but hey, to each his own.

[bku46]

ZeroCool, I guess you havent been in the HVAC field too long, You dont have a clue of what your talking about. Spot coolers have been around a long time and never caused any problems that you claim. GET REAL DUDE!!

[service guy]

I agree with Bku spot coolers are no big deal, Every setup is not the same so it may not work for you but I have setup alot for emergency cooling usually I can make it work. Miket I would think about some backup cooling for your server room main system goes down you have some protection I think mini split is a wise choice it's a one shot deal are you going to rent a spot cooler everytime the AC is shutdown the mini split will pay for it self after 3 or 4 shutdowns. I'm not a salesman I'm giving you my honest opinion.

[wolfdog]

The spot cooler requires the condensate tank to be emptied and takes up valuable floor space.
Invest a little more in the mini split and you will be happier to have it on the roof and out of the way.

[ZeroCool]

Burger King Uniform waist size 46 is always right. Put in a unit for permanent operation that is listed as Temporary/Portable cooling. Why put in a split system in your house when you can use a window shaker like he has in his 14x60 double wide trailer. Speaking of Dudes, shouldn't you be picking a fight with one at the trailer park you live in for hitting on your baby's moma, DUDE. Get real, mall electrician. Miket, do yourself a favor, call another commercial installation company, get a second opinion and get them to permit the job to make sure its up to code. If thats what you want, then give it a try.

[rubobornot]

Real Cheap = Spot Cooler

Real effective = Mini Split with condensing unit in plenum

Really the Right way = An actual computer room system with the condenser outside or a water cooled condenser inside.

I just worked at a place that claims to have $250,000 invested in a server room that they are trying to cool with a spot cooler, never works right but all they do is complain that they can't afford the server to go down. And they don't want to spend 3-4 % of that total investment to cool the room right, why shouldn't the cooling equipment for a room of that nature be looked at the same way as the equipment it is trying to cool?

[R12rules]

Do a search for renting a spot cooler. Since this is temporary .... the expence is a 100% write-off.

[snipe70e]

He is tlking about a perminate not temporary insulation. that will run onloy on week ends.

If it will work will depend on building. I use to work in a set of high rise buildings and on a emergency situation we have used spot coolers. Some with sucess so with failure.

One of the failures was a large server room with a water source heat pump and demising walls on all sides. The discharge from the spot cooler was into the cieling return air plentumn. Because the condencer fan was pulling air from the room through the condencer to the cieling and back to the room it did not work. On the first day the temperature was OK. but by the second day it would begin to climb, by the third day it was better when the spot coller was turned off. The sorry thing was I could never convince the regioal engineer this was happening. His solution was to put in more spott coolers.

Class A buildings do not allow tenants to use them for a different reason. If the tenant wants 24/7 cooling they will have to put in a AC unit for the server room with a electrical meter. The landlord does not want to pay for the cooling twice and therfore will require the tenant to remove any spott coolers.

[dan sw fl]

Originally posted by rubobornot

Really the Right way = An actual computer room system with the condenser outside or a water cooled condenser inside.

... why shouldn't the cooling equipment for a room of that nature be looked at the same way as the equipment it is trying to cool?

Miket,

Do you require a RELIABLE A/C system?

IF Yes, READ complete post by RUBBOORNOT.

Do you require an ABSOLUTELY Reliable system?
If Yes, consider Liebert and electrical generator.