Cooling a large warehouse!

[robwizard]

As some of you guys might remember I run a skatepark with a couple of other guys.. and in the summer the heat is ruthless! We are located in an old warehouse unit with a roof of cement/asbestos panels, clear plastic sheeting and assorted bits of metal and expanding foam! Little to no insulation and two doorways, one massive and the other quite small. The unit is approx 8,000 sq ft.

My question is this.. can anyone think of a viable way of reducing the temperature? I have been looking at some of them big 40" warehouse fans.. I thought sticking one of them by the big door to blow cool air in might help? But I'm concerned at the cost of running it? I have seen examples in the USA of people using solar powered ceiling fans but I'm not sure that would be an option here as the roof is really high and the cost of setting that up would be pretty nuts I reckon.

anyway if anyone has any suggestions I would be glad to hear them, I figure a lot of guys on here must work in large units and warehouse?

Cheers

 

[Spark plug]

Roof mounted fans are probably the best place to start the will draw the hot air out from the top of the building, causing cool air to be drawn in through vent doorways etc.

I don't think solar powered fans will be up to it as you will have a very large amount of air to move in order to make any difference.

 

[wristpin]

Whether it's heating or cooling a badly insulated building it is going to cost.
You mention bits of foam insulation but spay foam on the underside of the roof sheeting will reduce heat soak from the sun. - again not cheap.
There was/is a firm called Colt Ventilation who advertised in Industrial Exchange and Mart who make venting "chimneys" that sit on the roof apex and open automatically to allow warm air out by convection drawing cooler air in through low level vents - no fans or energy input required.
Farmers dry grain by blowing cold air through ducts in similar buildings but it takes energy to do it.
I don't think that standing a fan by the door will be effective unless there is a matching "exhaust" to create air movement.

 

[Robotstar5]

We had "fire exhaust fans" in the roof of the factory (designed to clear smoke) and we ran them in reverse to blow downwards in warm weather. The maintenance manager decided this was just blowing the warm air from the roofspace down so it would be more effective to run them normally to draw the warm are out and cooler air in from the doors, the workers complained they were no good, I can only think it was psycological (sp) feeling the draft on them?.

 

[awemawson]

I had 100 mm of spray foam put on the inside of my barn when I converted it to a workshop. Made a HUGE difference but cost thousands.

Cheapest cooling is drawing your input air through a water curtain, but obviously it has humidity implications, and if the water re-circulates you have to guard against Legionaries disease.

 

[brightspark]

3 choices insulation on the inside . solar reflective paint on roof and roof fans .roof fans are best as the heat is in the roof so u already have the convecton to pull the lower cool air up and through and the fans pulls it out even faster

 

[edd]

I am working in a new distillery which, when running, will generate loads of heat.
The building is designed with vents at high level and inlets at floor level on 2 walls.
The floor vents run the length of the walls.
The natural convection is used to circulate the cooler air.

Fans are great if you are stood In front of them, not much will be felt everywhere else.

 

[Rudi McAnichal]

…venting "chimneys" that sit on the roof apex and open automatically to allow warm air out by convection drawing cooler air in through low level vents - no fans or energy input required…

The higher the roof, the better this works. Use of “stack effect” is common practice for livestock buildings, and options include “protected open ridge”, spaced roof sheets, etc. Several websites explain design calculations. For retro-fit, the choice of method is very dependent on spacing of the top purlins, and on whether you need total exclusion of moisture or can tolerate a small amount of rain penetration. It would be worth visiting farms or cattle markets to get some ideas.

Vents high up in gable walls are another possibility. We opened access panels about 20m above ground level in a tall building, and were nearly knocked over by the blast of air.

 

[dannyp]

there is no cheep way.

40" fans are unlikey t help much bt will at least make it look like your trying. as for cost of running them its going to be next to nothing compared to the other options

 

[robwizard]

Hmmmm.. insulating the roof is out of the question really so I guess none of the other things will do that much either. I have a few big drums of aluminum paint which appeared one day.. it is for roofing I believe. That might help to reflect some of the heat away? And there are already three big vent holes in the center of the roof so perhaps installing fans into them to draw some of the heat might be the best way to go?

 

[brightspark]

Hmmmm.. insulating the roof is out of the question really so I guess none of the other things will do that much either. I have a few big drums of aluminum paint which appeared one day.. it is for roofing I believe. That might help to reflect some of the heat away? And there are already three big vent holes in the center of the roof so perhaps installing fans into them to draw some of the heat might be the best way to go?

as i said earlier natural convection of heat up through holes in the roof and with the fans pulling is the best option

 

[robwizard]

Thanks Brightspark! That is the route I shall go down

Cheers

 

[Psychosaffa]

Paint the inside of the roof black, and paint the outside of the roof white. I've seen it done to shipping containers used as storage in South Africa, and it seemed to make a big difference.

 

[rtcosic]

Paint the inside of the roof black, and paint the outside of the roof white. I've seen it done to shipping containers used as storage in South Africa, and it seemed to make a big difference.

I understand painting the outside white or silver to minimise solar gain, but I'm puzzled about painting the inside black?

How does that help?

 

[Psychosaffa]

Black absorbs heat on the one side, and the white or silver will reflect it away on the other side. It seemed to work quite well.

 

[KemppiFrog]

You could try evaporative cooling by having fine sprinklers on the roof. Esp with fibre cememt panels being vaguely porous.

 

[julianthegypsy]

Spray foam insulation is probably the easiest if you go that way. They come in and hit it and its done in a day. Makes a huge difference, winter and summer. Then roof vents as suggested will make another big difference. With insulation and proper venting, you shouldn't even need fans if the roof is quite high.

 

[SiPMerlin150]

unless it got to the 40 degree C inside like it did here last november, it's livable

 

[steviec_lj]

Paint the inside of the roof black, and paint the outside of the roof white. I've seen it done to shipping containers used as storage in South Africa, and it seemed to make a big difference.

Black doesn't absorb heat though.

A black object absorbs all wavelengths of light and converts them into heat, so the object gets warm.

A white object reflects all wavelengths of light, so the light is not converted into heat and the temperature of the object does not increase noticeably.

So yes, paint the outside white to reflect the light.

 

[lchris21]

google transpired solar collectors.......use the sun to your advantage to reduce your heating costs when the temperature drops and help reduce your overheating problems when its out???
must be plenty of government grants out there for green energy projects