I have a shed in my backyard that I am converting into a shaping/glassing space. I live in Hawaii. It gets hot and humid here. I want to put in an A/C unit into the wall. However, I also would like to work with the door open from time to time. What kind of ventialtion will I need? I have read a lot of info about ventiallation but haven’t seen too much info about using vents along with A/C. That kind of ruins the point of having A/C right? My shed is 15’x8’ and about 10’ tall. I have insulated and put 1/4’ plywood on the walls and ceiling to try and help keep it cool. There are no windows or vents as of right now. I have a double door opening and its nice to have open, but no air is flowing while open. Once installed, if the A/C is on, do I need any kind of ventialltion?
For health you need good ventilation. Best one’s is when new air is diffused from all ceiling surface and vaccum from all floor surface like in paint car room. Ideally air go through you from top to bottom at around 0,3 to 0,5 m/s speed. But like many of us you don’t built your room around ventilation system so you need to adapt. You want air come from larger surface from top and suck out at bottom of room through a filter to capture most “big” particule. Up to 10 micrometer, it’s not so difficult with high surface coarse filters. For flow rate you want to change all room air volume at least every minute. In metric it’s 4.5x2.5x3 (your room dims in meter)= 34 m3, 34*60=2040 m3/h is useful flow you need. Nominal flow of your fan box will depend from filters you use. Coarse G4 filters are good if you take air outside directly and for capture inside particules filters. Final pressure drop, when you need to clean/change this kind of filter is around 150 to 200 Pa so you need fan box that give at least 2000 m3/h at 200 Pa. For good efficiency it must be centrifugal fan box. From there you can work up to a realy simple system, open door and put a big axial fan at opposite wall like many shaping room. If like me you must reduce noise and capture particules you need to go with filters and centrifugal fan boxes.
Get around to a few shaping bays and observe their set-up. Having shaped and rented other shaper’s bays in Hawaii; I can tell you that the average bay has a 110 AC window mount hanging on the wall. If you put a vacum on your planer dust is greatly reduced. It is good to have some kind on exhaust/ventilation, but if you are in the bay on a hot day and running AC, you can’t have that open. If you want to shape with doors open or a fan exhaust running, do your shaping between 2:00 and 6:00 AM. I think what you will find for shaping bays in Hawaii is very basic. 110 AC.
Go down to The Surfboard Factory and ask around. I think it’s in Kapolei. Maybe somebody down there will look kindly on a brother and show you a hand shape bay or two.