insulated 30x40 - exhaust fan recommendation & Dehumidifier

I have a 30 deep by 40 wide by 12 foot tall red iron steel building with (2) 10ft x 8 ft non insulated roll up doors on the 40 ft side & (1) man door on the 30 ft side of the building; I have also added a carport style building in front of the shop against one of the large roll up doors. Building is approximately 12 years old and is fully insulated, however the roll-up doors do not seal well at the floor. I have been using this shop for the last 5 years and for some reason this year has just been unbearable to use in the peak of summer. I don't have a thermometer out there but it has to be over 90 degrees and a TON of humidity inside the shop. I have a desk job and am not used to working in these conditions and while I can do it honestly it is making it hard on me to want to work on cars in the shop in these conditions. This is a hobby of mine and on average I spend 3 hrs-ish two nights a week and occasionally 6-8 hrs a weekend in the shop working - so it is very low use environment. I do not currently have any shop fans or exhaust fans so the most movement the air inside the shop gets is when I open all the doors but it is VERY minimal and does little to escape the air.

I have two issues:

1. The heat is outrageous I don't want to install an A/C system I just want it to be more comfortable so I will not dread working in the shop and getting drenched with sweat.

2. I have a lot of humidity inside the shop. In the winter time the cars & my chrome tools and toolboxes are covered with dew.

I don't know if a shop fan would help both of these issues or if I need both an exhaust fan and a dehumidifier?

I was looking at this 18" 3000 CFM fan with shutters attached to it from Northern tool (link below) I'm not sure if this is too big or not big enough, I am new to construction/remodel. I literally do not know anything about this type of stuff but I am very mechanical so I should be able to get it mounted no problem.

http://www.northerntool.com/shop/tools/product_200446030_200446030


My other question - what do I use to control the fan? just wire it to a switch and cut it on upon entering the shop or should I have it on some kind of a thermostat? can someone please point me in the direction on this?

Thank you all for the help!
-Gibson

The Northern fan is a good value choice.

Check this out before you decide - http://www.globalindustrial.com/g/hvac/exhaust-fans/exhaust-and-supply/exhaust-fan-shutter

I would use a variable speed switch, but just a switch is maybe good enough.

I have specific info on both on an old computer, will try to get it for you.

Obviously, make sure you have intakes, door open, or door closed w some intake vent(s). Marc

These things really range in price at same CFM.

Global is generally less $ than Northern.

Do your homework if you want to save $.

I spent alot of time on this item for our future building, similar to yours.

I will try to get you my specific info- final buying links - off the old comp. Marc

I tell ya, if you spend $600 on a 24kbtu "wall" ac, cut a hole, build a shelf outdoors, AND locate it where it would blow where you spend the most time, I really think you will be verrry happy you did it.

We are building a 30x40x10, will be splitting in half w a "movable" wall, and plan on getting 2 12k btu ACs for that half, southern E Tx.

Gonna rig it so I can turn it on from the house an hour before I go out.

I expect $60/ month in summer to do this like the hours you are saying.

Even just hang a 4 mil poly wall to seperate your cooled area if nothing more. Marc

Trying to help you how I can cause I really feel your pain .

It REALLY ***** when conditions hugely damper your enthusiasm to create and produce. Marc

Hey Marc, Really appreciate the help!

What do you mean by intake vents for the fan?

You are right it REALLY *****, I have 8 cars and 2 four wheelers to maintain and a lot of work I need/want to be doing but with it being so hot I have to go out there after dark and I still come back in needing a shower no matter how little or easy the work I am doing is. I just ordered a humidity monitor from amazon so it should be here tomorrow, I want to see how bad it actually is in the shop and then measure after the fan and see if I can tell a difference.

I think I want to start with an exhaust fan and see how that goes then decide if adding the AC is worth it. Do you have any recommendations on some kind of an auto switch or thermostat control for the exhaust fan?

maroon88iroc -----

What kind of climate, or State are you located in ?

I'll come up with some ideas for you. Marc

In the meantime, Id like to see an HVAC guy more familiar with whats available chime in with simplest/ cheapest line voltage tstat recommendation.

I'll find you a speed control. Marc

Intake example -

http://www.aikencolon.com/schaefer-ws-200-aluminum-exhaust-fan-shutter-outlet-20-inch

http://www.aikencolon.com/assets/im...inum-exhaust-fan-shutter-outlet-datasheet.pdf

Oh, and when looking for fans, think "Agricultural ventilation"

Various farm buildings are the main use,hence marketing exposure for them.

I did a bunch of study, will yet find you the detail end results. Marc

Where are you located?

An inexpensive window ac or mini split really should be considered. Even a small ac unit can extract a huge amount of water out of a closed building and will have a big impact on keeping your tools and vehicles from rusting.

You really should do an internal fan as well and I personally would do an inexpensive ceiling fan and window ac unit over an exhaust fan which will not help the humidity as the lowest cost solution.

Based on your description, you have similar conditions to here in Mi where the cool nights make your interior cool, then you open the doors and the hot humid midday air flows in and condenses on everything. Using a fan to pull even more air in will really make it rain...until it is as hot as outside and your tools warm up too. A far better strategy is to condition some air and then minimize exchanging it with the outside under these conditions. If you were in a hot dry region, then the exhaust fan idea would make more sense IMO.

Radix is right on.

But, depending again where you are, there will be times of year when the high cfm exhaust fan will be a major asset.

Not so much the answer during high humidity.

Think of- roll up 4-6 mil poly walls, like huge "Roman Shade" rope mechanism, may be appropriate for you to contain most of your AC.

You'll certainly lose some of your AC money, may may be good overall in some situations. Marc

Location is central Georgia, temperature is mostly 95 degree's plus outside during the day and high 70's at night with humidity between 50% - 70% That is all current weather forecasts. I do not know what the inside temperature and humidity is but I ordered a humidity monitor last week that is supposed to be delivered today so I can tell you all this week.

Note that if you have an exhaust fan, you also need provisions for air intake. Depending on how tightly the building was built you'll probably get air leaking in around doors and windows but it should really have an intake louver matched to the size of the fan.

Also, if you have an exhaust fan (and air intake louver) a dehumidifier won't do any good, it will be like trying to bail out the ocean. The building needs to be sealed up for the dehumidifier to work.

Stuart in MN said:

..... The building needs to be sealed up for the dehumidifier to work.

Click to expand...

Exactly as I was thinking. Dehumidifier will help but it'll still be hot out there if you do were to seal it and run a dehumidifier.

Option 1: Look at a A/C unit and dehumidifier?

Option 2: Just get some high volume fans and start circulating air in order to keep yourself cool. Not gonna help your humidity problem.

Re: insulated 30x40 - exhaust fan recommendation & Dehumidifier

I'm in NE GA, your temp and humidity are going to look something like...



Edited for the correct pic. That's just now, in a stick built insulated garage. If life will cooperate, I'll have a mini split running in a few days.

Jason

Check this out. You have a number of options for control offered by Tjernlund.

http://shop.tjernlund.com/collectio...transfer-fans/products/cool-breeze-garage-fan

Pronounced as: CHURN-lund

my humidity gauge came in yesterday and I stuck it out in the shop this morning. Still hasn't got hot outside yet, Outside Temp was mid 70's.

89% humidity and 72 degrees inside the shop this morning at 7:15. I am going to leave it out there all day and will report back this afternoon what the results are.

Sorry, but $399 for 1200 CFM is way to spensive, even though it says including control. Marc

Folks REALLY need to search threads.

A window A/C will cool and dehumidify, but will cost a lot more to run than a standalone dehumidifier.

Had the humidity monitor in the shop all weekend, high temp recorded was 91 degrees with 78% humidity... Even when I was working in the garage last night - after 10 pm it was still 81 degrees and 71% humidity in there.

Its hot and I need to do something about it. I'm hearing different opinions - what should I do? It sounds like the best option would be to look into a mini split and an over head fan?

What do you all think about this 24K BTU mini split for $1,100

https://www.amazon.com/dp/B01DVW6FWK/?tag=atomicindus08-20

Pioneer gets good reviews as an affordable choice. The MRCool DIY I just installed looks exactly like that first pic with a different sticker, so we will see how it does. In the first two hours it ran yesterday, it dropped humidity 30%. Felt much cooler before the temp even dropped much.

Jason

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