estesbubba Posted August 9, 2015 Report Share Posted August 9, 2015 I insulated my shop well and even on the hottest days it stays under 80 degrees in there. The problem is most of the summer the humidity in there has been in the upper 70's even when it's less outside. Now it's tolerable to work in there with those conditions but I'm finding the humidity isn't good for table sled runners and spraying waterbornes. All 3 of my table saw sleds won't even drop all the way into the miter slots and they're made of QS hard maple. So do you guys think a dehumidifier would do the trick? I have a 1200 sq/ft shop and wondering if anyone has suggestions? I don't have a floor drain but could probably pop a hole somewhere for it to drain outside. Quote Link to comment Share on other sites More sharing options...
Tpt life Posted August 9, 2015 Report Share Posted August 9, 2015 Mike, did you sheet with OSB? Is there a vapor barrier under the OSB? Did you paint the OSB? A dehumidifier will help, but it is nice to know why the humidity is being retained. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 9, 2015 Author Report Share Posted August 9, 2015 OSB is painted with poly vapor barrier under it. Concrete floor isn't sealed which could be adding moisture. We've also had a very rainy spring and summer. Quote Link to comment Share on other sites More sharing options...
Tpt life Posted August 9, 2015 Report Share Posted August 9, 2015 Sealing the concrete is recommended by some, and avoided by others. You certainly will get some moisture moving through. The OSB being painted means that it will take on and release moisture more slowly. This is not a value statement, just the way it is. If I recall, your shop is enormous. The size of the unit needs to be figured for the space or it will run all the time to no effect. AC in the plans? Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 9, 2015 Author Report Share Posted August 9, 2015 Shop is 1200 sq/ft and 120,000 cu/ft with R-19 in walls and R-44 in ceiling. My original plan was to get some type of AC unit but since it's under 80 on hot days it's not too bad in there. Also my windows slide horizontally instead of vertically so window units are very limited. I'm looking at a 70 pint on Amazon which I can get open box for $180. It says it can handle rooms up to 1400 sq/ft. With it hovering around 78% in there during summer, if it could get it to 50-55% it would make a big difference. The humidity number isn't as important as getting the table saw sleds to work again http://www.amazon.com/Frigidaire-FAD704DWD-Energy-70-pint-Dehumidifier/dp/B00AU7GZXE/ref=sr_1_1?ie=UTF8&qid=1439139796&sr=8-1&keywords=frigidaire+dehumidifier 1 Quote Link to comment Share on other sites More sharing options...
Janello Posted August 9, 2015 Report Share Posted August 9, 2015 (edited) Lack of air movement is the problem, Mike. Get a fan going and you'll see the humidity drop down below 70, even with windows closed. Edited August 9, 2015 by Janello Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 9, 2015 Author Report Share Posted August 9, 2015 (edited) Lack of air movement is the problem, Mike. Get a fan going and you'll see the humidity drop down below 70, even with windows closed.With the dew point 80 and humidity 94 outside I'll hold off testing this as it will probably raise it! Edited August 9, 2015 by estesbubba Quote Link to comment Share on other sites More sharing options...
Janello Posted August 9, 2015 Report Share Posted August 9, 2015 With the dew point 80 and humidity 94 outside I'll hold off testing this as it will probably raise it!I didn't mean to imply bringing in outside air with the fan....just moving....circulating the inside air will drop the humidity. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 9, 2015 Author Report Share Posted August 9, 2015 I didn't mean to imply bringing in outside air with the fan....just moving....circulating the inside air will drop the humidity.Oh I know I was just joking its damn humid today! I'm going to turn on my heater blower now and check it in a few hours. Quote Link to comment Share on other sites More sharing options...
Tpt life Posted August 10, 2015 Report Share Posted August 10, 2015 Lack of air movement is the problem, Mike. Get a fan going and you'll see the humidity drop down below 70, even with windows closed.Defies my experience. Certainly won't hurt to try. Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 10, 2015 Author Report Share Posted August 10, 2015 Well the heater fan and air filtration have been running for close to a day and the humidity has bee 78-80% the entire time. Ordered the dehumidifier yesterday and hopefully that will do the trick. If it weren't for the table saw sleds I probably wouldn't care. Quote Link to comment Share on other sites More sharing options...
Janello Posted August 10, 2015 Report Share Posted August 10, 2015 Well the heater fan and air filtration have been running for close to a day and the humidity has bee 78-80% the entire time. Ordered the dehumidifier yesterday and hopefully that will do the trick. If it weren't for the table saw sleds I probably wouldn't care. Maybe it's because there is a lack of Air conditioning. All I can tell you is that I was running my A/C at about 70 deg and my humidity reading was 70%. I ran a pedastal fan for about 20 minutes and the humidity reading dropped to 60%. Quote Link to comment Share on other sites More sharing options...
WillieIV Posted August 10, 2015 Report Share Posted August 10, 2015 Mike, I'm in Iowa and can feel your pain. I have a similar set up in regards to insulation in my shop although it's smaller than your's - 24' x 32' w/ 10' ceiling. I purchased an 18,000 BTU window AC unit and had my contractor cut a hole in the wall for it. It stays in year round and during the summer I set the thermostat on it at 75 degrees. This is the first year the humidity in my shop got to the 80% level and I'm saying its due to the crazy wet weather we've had here in Iowa. No matter what I did for temp on the AC I couldn't get rid of the humidity. I ended up buying a 60 pint Frigidaire dehumidifier and after the first week of running I'm down to 50% humidity. Now that I've been down to that level at the most i have to dump the water bucket once per week. So far it's doing a great job maintaining the humidity. I don't think you'll be sorry with your purchase. I'm happy I did it. Quote Link to comment Share on other sites More sharing options...
AceHoleInOne Posted August 10, 2015 Report Share Posted August 10, 2015 Have you tried bring the sleds in the house? Hopefully your home is air conditioned? Maybe get a few hours out of them before they swell again with moisture. -Ace- Quote Link to comment Share on other sites More sharing options...
Tom Cancelleri Posted August 10, 2015 Report Share Posted August 10, 2015 Mike, stop trying to fit your Roubo in the miter slot, and your problem will be solved. Have you thought about mini split A/Cs? Quote Link to comment Share on other sites More sharing options...
Tpt life Posted August 10, 2015 Report Share Posted August 10, 2015 Maybe it's because there is a lack of Air conditioning. All I can tell you is that I was running my A/C at about 70 deg and my humidity reading was 70%. I ran a pedastal fan for about 20 minutes and the humidity reading dropped to 60%. This makes more sense. You are using the AC as a dehumidifier (for the sake of this discussion) and the fan just kicked up some dead air. 1 Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 10, 2015 Author Report Share Posted August 10, 2015 Mike, stop trying to fit your Roubo in the miter slot, and your problem will be solved. Have you thought about mini split A/Cs? I've thought about it but haven't had the need yet because:1. I just don't do much woodworking in the summer because I'm busy with a lot of other stuff and if I did it year-round don't think I would enjoy it as much. For me, woodworking season starts when football season does - there's nothing like having the games on while playing in the shop. 2. On the hottest days it's under 80 degrees in there which is pretty tolerable. If I start to think it's warm in there, I just go outside for 5 minutes and sweat my ass off, then go back in and it feels like AC. Here is something interesting. I have a friend who has a pole barn that is bigger than mine and he hasn't insulated it yet. He has a 9500 BTU portable AC and it does nothing to lower the temp or humidity. Yesterday he decided to run it in dehumidifier only mode and it dropped the humidity 15%. Quote Link to comment Share on other sites More sharing options...
rodger. Posted August 11, 2015 Report Share Posted August 11, 2015 (edited) My last house was built right on top of the water table, and the basement would never get below about 65 RH, with a dehumidifier running 24/7/365. The floor would get damp in spots at times, and I also ran two ceiling fans down there. I was always worried about finishing the basement as the humidity was ripe for nasty stuff to grow.I sold that house last year, so I believe the new owner has installed some type of full house dehumidifier or such. He stores antiques down there. Edited August 11, 2015 by franklin pug Quote Link to comment Share on other sites More sharing options...
Jeremy Carlsten Posted August 12, 2015 Report Share Posted August 12, 2015 Mike, I'm in Iowa and can feel your pain. I have a similar set up in regards to insulation in my shop although it's smaller than your's - 24' x 32' w/ 10' ceiling. I purchased an 18,000 BTU window AC unit and had my contractor cut a hole in the wall for it. It stays in year round and during the summer I set the thermostat on it at 75 degrees. This is the first year the humidity in my shop got to the 80% level and I'm saying its due to the crazy wet weather we've had here in Iowa. No matter what I did for temp on the AC I couldn't get rid of the humidity. I ended up buying a 60 pint Frigidaire dehumidifier and after the first week of running I'm down to 50% humidity. Now that I've been down to that level at the most i have to dump the water bucket once per week. So far it's doing a great job maintaining the humidity. I don't think you'll be sorry with your purchase. I'm happy I did it. The rain and humidity here in ia has been aweful! I went out to my shop after not being able to for a few weeks and found my crosscut sled with mildew on it! Quote Link to comment Share on other sites More sharing options...
Brendon_t Posted August 12, 2015 Report Share Posted August 12, 2015 Note to self, don't go to Iowa Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 13, 2015 Author Report Share Posted August 13, 2015 Got my dehumidifier yesterday and in 12 hours it dropped the humidity from 78 to 37! The humidity outside this morning is 90% so looks like this unit might do the trick. Only downside is it added 3-4 degrees to the inside temp but that was with it running in continuous mode. I now have it set to auto mode at 50% and see how the temp is. What is ideal humidity for wood shop? Good news is I tested my table saw sled and it slides in runners again! Quote Link to comment Share on other sites More sharing options...
wtnhighlander Posted August 13, 2015 Report Share Posted August 13, 2015 Ideal RH% for your shop would match the RH% of wherever your builds will eventually live. 1 Quote Link to comment Share on other sites More sharing options...
estesbubba Posted August 13, 2015 Author Report Share Posted August 13, 2015 Having the humidifier set at 50% does raise the temp 3 degrees but it feels the same in there. 81F at 50% RH has a heat index of 82F 78F at 80% RH has a heat index of 82F Not quite house comfort but definitely good enough for playing in the shop. Quote Link to comment Share on other sites More sharing options...
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