I have been doing research online for the past week on geothermal systems and I would like a little advice.  The company that I work for is located in central Missouri and we have welding shop.  During the winter the shop has some heating but since the welders are running the through out the day the air has to be circluated to get all of the smoke and smog out of the shop.  We would like to heat the air that is being pumped into the shop.  We are thinking about using 4 or 5 industrial exhaust fans for both sides of the shop to create a cross wind to free up the area of the smog.  The area that we are trying to vent is about 200' x 60' x 35' high.  A vertical closed-loop system would be the way to go with the way our shop is set up.  The heating does not have to be that much (about a 10 to 20 degree F difference in air entering and leaving) and what ever cooling that we can get is a bonus.  I am wondering what size unit and how many (if two smaller units would be better) that would work for our application.  Any other information would be helpful also.

Thanks

It is impossible to size a system w/o knowing the design conditions and the number of air changes you need per hour for your particular industrial application. My gut reaction given the size of the building you cite and the activity therein you are way past the single digit tonnage systems we discuss here.

I agree, there is 10 to 20 or more tons easy to do that. You cant economically air condition a space with those kind of air changes.

I think that your best bet is to cool the people directly. I assume that you are trying to get some relief to the folks actually doing the welding. A company called Movin-cool makes 1 and 2 ton water cooled units with wheels and 4" directional discharge ducts that can blow on someone thats really hot, like a welder. The water cooled units should Geo loop.

I've heard of Movin-Cools. Grainger sells them, I think. Pricey, if I recall. Geo-looping some kind of spot coolers makes perfect sense - forget cooling the whole space.

A new Walmart in my area has registers over the cashiers in the otherwise unconditioned seasonal area. I've seen the same thing over individual workstations at a massive ceramics factory in North Carolina (Lennox - the famous tableware)

Depending on the number of workstations, you'll still likely need commercial tonnage. Plan for 100% makeup air as you'll want to be certain to draw return air from a clean source, likely outdoors. No reason it can't be geo.

The atmosphere being so corrosive, it is common a paper mills to waterloop (sometimes plant wide) all the individual control and computer room HVAC units. Air source equipment dies early in mill conditions

Proper way to do this is via a mechanical contractor (not a local residential HVAC Co) to sort out all the nuances of this specific application.

Keeping the shop at say 72 degrees all year is not a big concern... We are looking to heat/cool the air that will be pumped into the shop to help out our current system. We have a system of pipes in the floor for heating. I was looking at 3 air changes/hour and placing some sort of radiator over the inlet fans.

Sounds like what you need is one or two big HRVs.

Sounds like what you need is one or two big HRVs. The HRV will recover the heat from the dirty air you are venting so you won't need to heat it.

A simple formula may help here.

BTUh = cfm x (1.08 x delta T)

With this, you could decide on the delta T (the change in temp. for the air coming in) after an HRV. You'd also know the cfm each HRV puts through it. Now, with that info, plug it in, and that will tell you the BTUh capacity you'd need for the preferred delta T of air. This would have nothing to do with the load of the building. Rather, it would have to do with the air exchange heat gain/loss.

If you did want to incorporate heating and cooling the building, that's a far more difficult/involved calculation. You'd need to have that engineered.