Ok so some build updates, design concepts, and some questions.
I stuffed the bays of the garage door with EPS foam so that when I stand the wall up, the OSB on the "inside-out" wall will touch directly against the door/foam. There will be no gaps, and it will be one continuous, sealed mass leaf. I attached the OSB to the frame, and with the help of some friends, we stood it up, and I secured it in place. Next up will be adding mass to the stud bays, then caulking the shit out of the perimeter and the drywall in the bays.
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Thinking a LOT more about the ERV situation, I started putting down on paper (or in this case, sketchup) how this would work/look. I'm not crazy about it because it's going to take up significant space in the room, but I am concerned with making sure I'm getting adequate fresh air in the room when I have 3+ people in there playing music, sweating, breathing hard, etc... as anyone should be. So here's what I'm thinking.
There are two ERV units that meet my needed specs.
This one and
This One
The first one is pretty small in dimensions and is much more affordable. It's marketed as an AEV (Air Exchange Ventilator), and by the descriptions, it seems to function much like an ERV or HRV, but for some reason doesn't have the same name. The second one is really slim (albeit longer and wider), so it would sit very high up on the ceiling, effectively not taking up much space at all. It is double the price, but it seems to be a good option. I understand Fantech is a good brand, so I probably can't go wrong with either one.
I will put the unit up towards the ceiling as high as I can on the north wall (which is where the garage door is, and where that new wall was built and stood up). The mini split will be on the west wall, and i'll have the fresh air duct feed the air right into the path of the mini split so it gets cooled/heated immediately. The exhaust duct will run along the perimeter of the room so that it's opening is on the opposite side of the room from the fresh air inlet. I imagine this will help make sure the air in the whole room is being adequately exchanged. I can build the silencer boxes so the supply and return ducts from the unit go directly into them, and then they penetrate the wall and take the air outside. This is how I imagine in. Please excuse the crude drawing of it. It's not exactly to scale, but you get the idea.
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I am thinking about possibly building the silencer boxes inside the wall, instead of inside the room. This would help maintain real estate in the room. What are your guys' thoughts?
I also don't know how I'll run the ducting inside the room. I don't want it to look like shit, so I'm hoping maybe I can make it look "industrial", while not completely killing the acoustics in the room. I don't have space above the ceiling to run the ducts, so they have to be run inside the room. any thoughts/ideas/examples of how running a duct in the room could look/work?
I am about to build the interior frame, and as soon as I do, electrical and HVAC will need to be figured out so I can make sure I plan everything accordingly for when it's time to put up the OSB and drywall. I am planning on running a star grounding system with isolated ground receptacles. I have done a TON of research on how to do this, but I wanted to put it down on paper to run it by everyone to see if it makes sense, and is correct.
Right now I have a 200 amp main panel for the house. There is a ground rod right at the main panel, and another one at the front of the house bonded to the water pipes. Currently there is a 40amp sub panel in the garage, that is fed by 10ga wires in conduit underground. There are 2 hots, 1 neutral, and 1 ground wire. I want to turn this into a 60 amp sub panel, so I'm going to swap the 10ga wires with 6ga wires, and put a 60 amp breaker in the main panel. The only electrical penetration through my interior leaf will be the main power. I will be face mounting all outlets, switches, lights, etc to the drywall, all connected by conduit. As far as the star grounding system goes, I understand that each one of my IG receptacles needs to have a hot, neutral, and insulated ground. Each insulated ground will make a home run to a separate ground bus bar, that will then run all the way back to the main panels ground bus, but never touching the equipment ground bus (or ground conductors) in the sub panel. All the outlet boxes will be metal, and will be connected with EMT conduit, so that will act as the equipment ground for each IG receptacle. So this means I will need to run a 5th conductor (the isolated ground wire) through the conduit back to the main panel. These isolated ground receptacles (I'm thinking about 7 total) will be for audio gear only. I will have regular outlets and circuits for other things like lights, AC, refrigerator, etc.
Do I have this right? A diagram would probably be easier to understand. But with everything I've read and seen, this seems to be the correct way to do this. Anything I'm forgetting or should be aware of?