Bandaiding insulation in metal building

[Robert Adams]

Ok I have the typical welded metal building. 2" square tubing on roughly 5' centers then covered in metal building insulation then the R panel is screwed to the frame. I am going to be spending allot more time in the shop working on the mustang and taking a break from woodworking. My shop is 20x30 insulated with 2 tons of AC which is not adequate in the summer. Right now it is 103* and 51% humidity. So heat index of 128 and summer is just getting started. 

     Well since the insulation is 100% compressed between the framing and skin that makes the entire frame of the shop essentially one massive radiator conducting heat in from outside. That framing gets quite hot. 

     My doors are insulated with the same fiberglass and are sealed up fairly well.

    

           Does anyone have any brilliant ideas to insulate that framing. The best option would be to take the sheet off and add a layer of foam then resheet the outside but that's not going to happen... So the only thing I can come up with is to take the scrap insulation I have and cut it to long strips to basically just cover the framing and then tape it to the existing insulation. On the upside that will cover up the ugly red tubing as well and it will all have the white vinyl showing.


             Oh and I am looking for a heat exchanger to run the well water through to help cool the shop. The water temp is 68-70 out of the ground and I might as well use that to cool the shop when the yard is getting watered. I think in the future I will replace my 2 ton unit with a 3 ton package unit which is much easier to filter the air for than minisplits. The best solution is to move north but LOML is making that very hard to do.

[whatline]

Google DuroDyne. They sell attachment fasteners to hold insulation to ductwork. They have a self adhered plate with pin you can put on the steel. Once the insulation...yours or even fiberglass duct insulation gets pushed onto the pins there a a plate that snaps on the pin to hold the insulation in place

[Robert Adams]

Google DuroDyne. They sell attachment fasteners to hold insulation to ductwork. They have a self adhered plate with pin you can put on the steel. Once the insulation...yours or even fiberglass duct insulation gets pushed onto the pins there a a plate that snaps on the pin to hold the insulation in place

      I forgot about those. The guys that do the commercial HVAC use them on their supply plenums. I will keep those in mind. If i go the tape route I will need about 400-500'(maybe more) of tape but even with the pins I will still have to tape them. Metal building tape comes in 150 foot rolls. 

      I like metal buildings but they are extremely difficult and costly to insulate after construction. If I built it I would have stick built it then put a blanket of poly iso around the framing then the steel. Oh and on metal buildings you have no walls to hang anything on so you have to add steel or stick build inside and plywood it. Basically build the building twice...

[daddo]

70* water isn't going to do anything. All your efforts, resources and money will be wasted.

On the 2" beams- Where will the heat go after insulating them? Most of the heat will still radiate into the building over the course of the day if you use only 2"- 4" of insulation. I'd use at least a R30 or better with an air gap. The rest of the heat will move back outside where it came from when the sun goes down. Far better to stop it than trying to divert it, but insulating them sure won't hurt.

I installed a 4 ton split system heat pump in a shop much like yours (30x50- 25' peak) and it will cycle on a 100* day (RH 70%) keeping it 76*- 77* in there. A 3 ton should do you fine.

[Robert Adams]

70* water isn't going to do anything. All your efforts, resources and money will be wasted.

On the 2" beams- Where will the heat go after insulating them? Most of the heat will still radiate into the building over the course of the day if you use only 2"- 4" of insulation. I'd use at least a R30 or better with an air gap. The rest of the heat will move back outside where it came from when the sun goes down. Far better to stop it than trying to divert it, but insulating them sure won't hurt.

I installed a 4 ton split system heat pump in a shop much like yours (30x50- 25' peak) and it will cycle on a 100* day (RH 70%) keeping it 76*- 77*  in there. A 3 ton should do you fine.

          I don't see why a 70* coil wouldn't take some heat away from a building when the air temp is 100* in it. All it takes is a radiator and a fan. The pipe coming out of the ground sweats like like I do outside since the humdity here regardless of temp. It would basically be just a supplemental and usually it would be running when the shop is very hot and the AC is not on.


            Ideally yeah I would put up allot more insulation. Just need to do something to slow the transfer of heat as that's all insulation does. The heat will get in no matter what it just slows it. I wish some of that heat would go back out as the sun goes down unfortunately in the summer it will still be in the 90s after midnight and it barely makes it to 80* as the sun comes up.

            Yeah I figure 3 tons would be about right based on how the 2 ton handles it. I had a 2 ton at the time so that;s what went in it. I will be adding onto the shop a paint room which will be about 18x20. Basically just extending the building another 18' longer bringing it to 58' long. I would like to make that more of an L shape so it would be deeper than the existing building but that makes for some odd tie into the existing building at the roof line.

[daddo]

          I don't see why a 70* coil wouldn't take some heat away from a building when the air temp is 100* in it. All it takes is a radiator and a fan. The pipe coming out of the ground sweats like like I do outside since the humdity here regardless of temp. It would basically be just a supplemental and usually it would be running when the shop is very hot and the AC is not on.


      

 The coil would only be 70* at the entrance and maybe only for a foot or so, depending on chilled water coil and air flow and GPM of water. The rest would just be warmed water. Plan on flooding the yard to make any difference of maybe 0.05*. The time, materials and even free labor just wouldn't be worth it- seen it tried before. You'd do a little better to heat the shop in the winter with that.


If you had 55* water (Approaching the 40*-45* used to actually cool) and good flow, it would be more productive, however, you're not removing much if any humidity, so your dropping temps and keeping humidity which might encourage sweating on surfaces.  

 Hey- it never hurts to try. I think you should experiment and let us know how it works.

[Robert Adams]

 The coil would only be 70* at the entrance and maybe only for a foot or so, depending on chilled water coil and air flow and GPM of water. The rest would just be warmed water. Plan on flooding the yard to make any difference of maybe 0.05*. The time, materials and even free labor just wouldn't be worth it- seen it tried before. You'd do a little better to heat the shop in the winter with that.


If you had 55* water (Approaching the 40*-45* used to actually cool) and good flow, it would be more productive, however, you're not removing much if any humidity, so your dropping temps and keeping humidity which might encourage sweating on surfaces.  

 Hey- it never hurts to try. I think you should experiment and let us know how it works.

        The well is only for irrigation and we have a little over a half acre so it takes a long time to water the yard. It will be running 10-15 GPM. The water feed from the well is right next to the shop less than a foot from the building so it would just 90* right into the building. I may have a line on a free exchanger so will see. 70* water does a very good job at removing moisture outside because the humidity is so high here. The pipe coming out of the ground sweats allot and even if I have my 220' of hose running out front it will start sweating along it's full length. 
       And going by the dew point calculator for summer temps and humidity the well water temp would still be 10* or more under the dew point which is roughly 80*+

          Did some temp measurements in the shop. The framing is running at 105* to 115* depending on where it is which is on the cool side. We had a cold front come through yesterday and drop some rain and the high is only 97* so far. We were 103* and 52% humidity yesterday for about 4 hours and 100* since about noon and finally dropped below 100* around 5pm when the clouds from the rain started.


             LOML was out in the shop inspecting the Mustang while I was working on it and we talked about the AC and I brought up adding much more insulation to the roof and she didn't like the idea because of the lower ceiling space which is also storage space... The better solution is to order a pallet of solar panels and get them on the roof. Electricity production and shade for the roof.

[blackhat]

I wouldn't rely on self stick pins.  Beg, borrow or whatever a pin spotter.  The adhesive will fail.

[CLETUS]

100 degrees and 80 degree dew point? Holy crap.

[Robert Adams]

100 degrees and 80 degree dew point? Holy crap.

   Yeah really nasty this summer. Heat indexes in the 120s. Lots of rain this year as in our yearly rainfall for several years this spring. Rarely goes under 50% so far. I have a weather station that I can go back and check the stats on. I have been cussing and POed much more than usual when I go outside. I hate living here so much it's a constant slew of 4 letter words when I am outside...