factory A/C too small

[Sledge]

Hi

So...here is the challenge; No money and too hot.

16,000 sq ft with 18 foot ceilings of light industrial factory, 50 people more or less, and minimal heat load from conveyor motors, and shrink wrap machines, divided into 2 rooms, 6000 and 10,000 sq ft respectively. Estimated 55-60 tons of cooling required to cool to 74 degrees F.

Also about the same sq ft of warehouse with skid shelving to the roof.

The intention is to attempt to find a way to vent some of the heat in the warehouse, and to cool the factory below 90 degree F in summer.

Until I came along they had quotes on installing a 7.5 ton cool only rooftop unit in each of the 2 factory rooms with no ducting, assuming cold air will fall and drawing R/A off the ceiling. I estimated the ceiling temp in the factory at 120-160 on a hot day. I think that the plan they have been sold on is not going to work and the grossly undersized unit will be subject to overloading and failure.
I was asked to quote and offered up 20 tons of cooling at the same price, in floor mounted split systems as a better alternative, thinking that they would work better due to the naturally lower temp at floor level..

I am having second thoughts, think that I am going to be dealing with a system that wont function well, and will be prone to failure due to excessive load.

Aside from installing 60 tons off cooling, any other ideas?

[momo]

Quick questions.
How humid is the area?
What season is it needed in ?
Are there humidity sentive products on the shelves?
Is the roof adequately insulated against radiant heat?

Reason: consider evaporative cooling with good air renewal flow... Quite a few US and Aussie firms manufacturer them and US manufacturers provide adequate design data for calculating the effectiveness of the principle. (Coast areas with sea breeze evidently of little use, but in the Prairies in a dry Summer it could help you.)

[LRAC]

Hi

So...here is the challenge; No money and too hot.

16,000 sq ft with 18 foot ceilings of light industrial factory, 50 people more or less, and minimal heat load from conveyor motors, and shrink wrap machines, divided into 2 rooms, 6000 and 10,000 sq ft respectively. Estimated 55-60 tons of cooling required to cool to 74 degrees F.

Also about the same sq ft of warehouse with skid shelving to the roof.

The intention is to attempt to find a way to vent some of the heat in the warehouse, and to cool the factory below 90 degree F in summer.

Until I came along they had quotes on installing a 7.5 ton cool only rooftop unit in each of the 2 factory rooms with no ducting, assuming cold air will fall and drawing R/A off the ceiling. I estimated the ceiling temp in the factory at 120-160 on a hot day. I think that the plan they have been sold on is not going to work and the grossly undersized unit will be subject to overloading and failure.
I was asked to quote and offered up 20 tons of cooling at the same price, in floor mounted split systems as a better alternative, thinking that they would work better due to the naturally lower temp at floor level..

I am having second thoughts, think that I am going to be dealing with a system that wont function well, and will be prone to failure due to excessive load.

Aside from installing 60 tons off cooling, any other ideas?

Forget it on the cooling side it will be mega bucks, you might have more success looking at evaporative coolers in the roof space.

Regards
Lrac

[lana]

Hi there,

As other gents said the only way (economic) is the evaporative cooling and this would work if the wet bulb temperature is not too high during summer.

Cheers

[Sledge]

There isnt an issue with the product being impacted by humidity. The plant is a privately owned re-packaging operation for drugs...Tylenol, Halls, Shampoos, etc. They put on bilingual labels, or package them for specialty promototional sales. They dont actually open up the tamper proof seals, rather they remove exterior shrink wrapping and labels, and rewrap it, etc. The product is not actually exposed to the atmosphere, anymore than it will be in the store.

The hot season is now until Sept. The humidity in Toronto is very high in the summer, making evaporative cooling not common.

There is no roof space, this is a flat roof, tar and gravel on tin pan, built on steel roof trusses. Doubtful that there is much insulation at all in roof. exterior walls are concrete block, minimal windows.

I was thinking of "swamp cooling", and a few roof top exhaust fans coupled with wall mounted barometric dampers.

I am also considering a series of fan coil units, circulating glycol, passing through a roof top dry cooler.

[frank]

So...here is the challenge; No money and too hot.

Says it all for me.

What do you expect for nothing?? - complete comfort??

Never mind guessing if you 20 ton of splits will do the job - why don't you carry out a full survey and calculations and then tell the customer what he NEEDS.

If he can't afford a proper job then walk away as the pain of trying to deal with an improper installation and a dis-satisfied customer will cause you to lose your hair like me!!

[Sledge]

Says it all for me.

What do you expect for nothing?? - complete comfort??

Never mind guessing if you 20 ton of splits will do the job - why don't you carry out a full survey and calculations and then tell the customer what he NEEDS.

If he can't afford a proper job then walk away as the pain of trying to deal with an improper installation and a dis-satisfied customer will cause you to lose your hair like me!!

I know! You are absolutely correct!

sometimes we get seduced by a customer who whines in just the right tone! The customer is at the moaning and hand wringing stage over the 20 ton quote. I was trying to come up with a cheaper creative approach, but I think I have to give the customer the formula

$dollars in=BTU out.

[momo]

Evidently evaporative can be deemed not suitable for your area.
Roof sounds a horrendous heat catcher, vented space and second layer of insulation would be a great help.

Apart from managers' offices and comfort ... there are good arguements for adequate T & RH control with respect of costs of A/C: product storage temperature for pharmaceuticals and cosmetics, manual operator errors and health and safety risks...

Basically, with higher temperatures operators make more mistakes on the production line and the danger of accidents increases... productivity/faulty workmanship creeps in with the associated costs of returned goods etc.

There is union, labour medical literature on this somewhere.
Happy hunting.