OSB vs. Plywood for Interior Walls in So. Florida

I have OSB on the inside of my 24' x 24' garage/workshop - 2x4 studs, kraft face insulation, 14" blown insulation in the attic - and installed a mini-split about 3 years ago and have had no problems. It keeps the shop cool in the summer and warm in the winter and has been surprisingly inexpensive to operate. The OSB makes it easy to hang things on the wall, although I still looks for studs if it's something heavy.

I guess that I should paint the walls one of these days to brighten things up......................

When I insulated by shed shop and office walls, I began by laying in that aluminized radiant barrier. The insulation went on top of that. I was surpirsed when we did the garage that the radiant barrier reduced roofing temperatlure by about 35 degrees. It only has an R rating of 4, but turning the infrared heat away is worth the effort to lay it in. I bought 4 ft wide rolls and cut them to fit between the studs. I also installed them between the ceiling joists, whice were not evenly spaced. Put R13 paper backed glass in next, then a 2 inch thick foam cut to fit precisely between the ceiling joists and held in place by finish nails hammered into the joists. No other covering on the ceiling. Walls are covered with a mix of ply and one whole 24 ft wall is covered in 1/4 inch pegboard. Never bothered with drywall in the shop. Stays warm in winter, but takes an hour to heat up when really cold. Small room AC cools nicely during summer here in the desert. I never painted the shops, just installed a lot of LED lighting

I can't offer much here as for the paneling but from what I used in the past in building I'd go OBS and save the money. Painting, well that's a personal choice. In my shop I hung all LED lights and they make any area bright. I took the fluorescent lights down and gave them away. I'll do the same in my garage before winter for sure. Now as far as the cooling units, here's where I'd pay close attention. Split, window, central all work the same. As a retired HVAC dude I can tell you many units were replaced when they only needed servicing, especially window and splits. I'm not a big fan of either but they do have their place. By splits I'm referring to units where the indoor unit is a wall hung fan and evaporator unit with the controls on it and the condenser (outdoor unit) sits outside with copper lines between them. Central units are similar except they have coils that are either sitting in a furnace or a boxed ducted air handler and the duct goes throughout the dwelling. The issue mostly is the return air. Regardless of system you have a fan and coil. The fan of course supplies air on the leaving side of the coil but also pulls room temperature air through the entering side into the cooled coil where the coil cools the air before supplying it back to the room. The coil is King and must be maintained (cleaned and filtered) properly or you will have declining performance resulting in higher operating cost, lower efficiency, and warmer air discharge. Installing the indoor unit where it is accessible for cleaning is extremely important. If used year round, a minimum of 1-2 times yearly depending on usage is best.

But key is filtering the air. Most all split units (wall hung) have a mesh type thin filter in the indoor unit which is almost useless but better than nothing. It requires a lot of cleaning and very often. Unfortunately there's little way to use a better filter in the unit due to the thickness restriction of the unit. I would think constructing a box that can fit in front of the indoor unit would allow the use of a 1" pleated filter. This allows much better air filtration thus keeping the coil cleaner. When you do need to clean the coil use an approved evaporator coil cleaner for the indoor and an approved condenser cleaner for the outdoor unit coils.

I use a 20x25x4" pleated filter in my central system at home. I installed this system 18 years ago and just replaced the indoor coil and outdoor unit (heat pump) but the gas furnace is still in great shape (dual fuel system with 5 zones). When we pulled the indoor coil off the furnace it was a clean and spotless as a new coil. That filter had stopped all the dirt from reaching the coil and kept the system very efficient over the years. It also prolonged the life of the system. I've replaced systems that were older but this one had developed a refrigerant leak that was proving very difficult to locate and we decided it was time to replace instead.

I know this is a long post and I apologize but most people have no idea of what should be considered when installing a unit. That includes window units. You'll need to take them out at least yearly and thoroughly clean them,especially the coils, so make sure they are accessible when planning. They are sealed systems like your refrigerators so putting gauges on them is not possible without installing ports which often led to leaks so temperatures are the only way to easily diagnose them. I've seen a ton of good units tossed and all they had were dirty coils. You should see 18-20 degree difference between room temperature and discharge temperature when working properly.

Feels a little weird hitting the "Post Quick Reply" button

Thanks for the post Steve. I like the idea of adding a 1" pleated filter in front of the indoor unit and will be looking into making or possibly buying one, if available. I hope the WEN air filtration unit that I'm installing helps with the dust. To help with the temperature I'm installing a radiant barrier under the R-13 faced pink stuff. Should help with the sun issue here in So. Fla.I'll be talking to HVAC guy about that filter when he comes to install the unit.

Funny how things go. Just when you think you've created the the best plan to get your shop up and running, you run into stuff that prolongs the process. I'll get progress pictures as I get really moving.

The electrical should be done by the weekend by a licensed/certified electrician. I have a 60A breaker in the main panel in the house and had a 6/3 wire run through the attic to a junction box outside the house and in front of the shed. He's running 6g THWN wire underground in a schedule 40 conduit into the old 150A house panel I'm using in the shed, then 12/2 & 14/2 Romex to the outlets. The 110v/ & 220v circuits are going to be on 20A breakers with each of the 6 220v outlets on individual circuit breakers. The 110v outlets will be split into 5 circuits - main lights, supplemental lights, air filter, AC (the mini unit is 115v), and 6 outlets.

OBG65 said:

12/2 & 14/2 Romex to the outlets. The 110v/ & 220v circuits are going to be on 20A breakers with each of the 6 220v outlets on individual circuit breakers. The 110v outlets will be split into 5 circuits - main lights, supplemental lights, air filter, AC (the mini unit is 115v), and 6 outlets.

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One issue here, 14/2 is only rated 15 amps. Your electrician can guide you on breaker sizes. How long a run is it between panels? Distance will have some affect on voltage drop if too far but again your electrician can make sure you're OK. Most of my work was design build computerized zoning systems. I did commercial and residential systems but what I enjoyed the most was control work. I cut my teeth on Carrier's VVT (variable volume, variable temperature) zoning systems and then their home controls (Comfort Zone). From there I learned Trane's zoning systems, Omni Zone, and Carriers fully modular system (name escapes me) that required a 6 week school to learn the basics for programing and designing. That was installed at a radar site with dual packaged systems, one duct system, alternating equipment runs, emergency backup starts in case one failed, and a ton of federal government requirements per the FCC. It was a nightmare and when finished, inspected, and passed they had us dumb down the system so their maintenance people could work on it. Basically went to T87 T-stats, relays and contactors while all those upto date and sophisticated controls went in a box never to be used again. All at an extra charge of course. The monetary fines for down radar site, not to mention the danger from lost coverage, is something no one wants to be dealing with. I saw the same with the telephone company and it's switch rooms, another big customer of ours. Redundancy is key and still there are times you can't cover everything. But that's another story.

Did I mention I'm glad to be retired......far less stress.