My New Studio Build (perhaps overly detailed)

[silky smoove]

Why not get a Bard unit like they put on the sides of portable school buildings. They are only a couple grand and have OSA supply.

Following up on this: They look like REALLY slick units. Conditioned air, fresh air, and a built-in ERV in a single package is very appealing. The problem is that they're big. Too big to locate on the cap blocks of the retaining wall, which is the only place the outdoor unit can live. The problem is depth. I can only accommodate something up to 13" deep, and the smallest of these units is just a little over 17". To hit ideal specs I'd need to go with the next size up from the bottom which clocks in at around 2' deep. That basically makes this a non-starter, which is unfortunate because they seem really cool.

With regard to AC. If it's a matter of not having it at all vs having to turn it off when you record the choice seems clear to me.

I agree, but if I can get it installed myself, minus the refrigerant hookup, there will be no reason not to just get a unit of sufficient capacity that it can run on a low setting while recording.

You'll also need fresh air regardless of if you do a ductless unit.

Correct, which is what I was getting at earlier. That part is a little tricky in terms of construction (i.e. making it as silent as possible), but not too bad. The main room ventilation will live in a chase that goes into the storage vestibule, which will eat up some floor space, but I'd rather lose it there than in the main room. I can use the top of it as instrument case storage, so not all is lost.

 

[mpm32]

Following up on this: They look like REALLY slick units. Conditioned air, fresh air, and a built-in ERV in a single package is very appealing. The problem is that they're big. Too big to locate on the cap blocks of the retaining wall, which is the only place the outdoor unit can live. The problem is depth. I can only accommodate something up to 13" deep, and the smallest of these units is just a little over 17". To hit ideal specs I'd need to go with the next size up from the bottom which clocks in at around 2' deep. That basically makes this a non-starter, which is unfortunate because they seem really cool.

This may not be optimal because you have carefully considered aesthetics when building your walls but couldn't you build a bump out of the wall that will serve as a pad for the 2' unit?

I just looked at the Bard site and although I didn't look at all of the specs, a lot of the units look to be wall mounted. Would one of those work for your application?

I would email them, give them your specs and see what they have to offer that fits your specs.

 

[silky smoove]

It's an exterior unit, and as such would have to sit on top of the retaining wall that's supporting the building. There are cap blocks at the top of said retaining wall that are 13" deep. There is no option to "bump out" that wall. If this were an interior unit (and they do make this variety) I could make adjustments to the interior framing, but I can't take the hit to floor space.

 

[bludog]

I just looked at the Bard site and although I didn't look at all of the specs, a lot of the units look to be wall mounted. Would one of those work for your application?

I would email them, give them your specs and see what they have to offer that fits your specs.

That was my first thought. Most mini split outdoor units can be hung cantilevered from the wall so you don't need to use the ground or roof space. This is common in cities.

 

[bludog]

Like this: http://cmrmechanical.com/contentimagedata/portraitforweb/7/mitsubishi-mini-split-outdoor-unit.png

Happens to be a different brand, but many of the brands will do this (LG, Fedders, Friedrich, etc.)

 

[silky smoove]

Hanging them off of the exterior walls makes sense, except that in a studio environment where minimizing wall penetrations, especially those associated with items that go all the way through the isolation perimeter (the HVAC system is the only component that does this on my build), becomes paramount. I'd rather go with a mini split than a self-contained unit. One with a floor-mounted interior unit and an AHU that's less than 13" deep will keep penetrations to a minimum and are also less expensive than these all-in-one units.

 

[beans-on-toast]

I've seen studios where to keep noise as low as possible, they had a separate building for the HVAC equipment and buried conduits running to the studios.

Could a unit mounted on the shed wall or a nearly ground slab with underground conduits be quieter?

 

[silky smoove]

Could a unit mounted on the shed wall or a nearly ground slab with underground conduits be quieter?

It definitely would be, but the construction would be infeasible. The trench distance would be quite long (~30') and would cut across an existing irrigation system. It's not cost feasible, and the noise savings would be minimal since the big problems come from wall penetrations, regardless of where the AHU is located. Additionally when refrigerant lines exceed 16' extra steps are needed to ensure a proper vacuum seal.

 

[Marial]

Sounds like the storage closet is really the only option. Man... what a journey. I'm sure it will be awesome when it's done though.

 

[bludog]

Hanging them off of the exterior walls makes sense, except that in a studio environment where minimizing wall penetrations, especially those associated with items that go all the way through the isolation perimeter (the HVAC system is the only component that does this on my build), becomes paramount. I'd rather go with a mini split than a self-contained unit. One with a floor-mounted interior unit and an AHU that's less than 13" deep will keep penetrations to a minimum and are also less expensive than these all-in-one units.

I'm not sure I was clear, this is a mini split unit (not self-contained/all-in-one AC). The interior unit is mounted where ever you want inside and the exterior unit is hung on the exterior wall. The only penetration to the interior is the small hole for coolant and power lines (one combo line). Yes, you would need to mount the brackets to the exterior facade but I'm not sure that would compromise your sound barrier.

You've done some very deep research so perhaps you've already vetted this option, but based on your reply I think you may have misunderstood me. Hopefully this is more clear and a viable consideration. I may be the one who is confused here, if so sorry to belabor a moot point.

Research metropolitan/urban apartment building mini split installations. In NYC, you see the mini split exterior units mounted on the side of buildings all the time - often on the 2nd and 3rd stories to keep off the ground and out of view. These are not self-contained PTACs or thru-wall ACs, they are splits. I work in appliances and I live in NYC, I see it A LOT. Best! Loving your project!

 

[beans-on-toast]

It definitely would be, but the construction would be infeasible. The trench distance would be quite long (~30') and would cut across an existing irrigation system. It's not cost feasible, and the noise savings would be minimal since the big problems come from wall penetrations, regardless of where the AHU is located. Additionally when refrigerant lines exceed 16' extra steps are needed to ensure a proper vacuum seal.

Who would have thought that the cost of HVAC and electrical would approach the cost of the building.

The tiny house community is pushing a lot of boundaries. Perhaps they have useful HVAC solutions. Tiny house studios?

 

[Marial]

Who would have thought that the cost of HVAC and electrical would approach the cost of the building.

The tiny house community is pushing a lot of boundaries. Perhaps they have useful HVAC solutions. Tiny house studios?

Probably not, the requirements, as silky pointed out, are completely different. Not to mention it seems like a lot of the impetus for the tiny house movement is to be environmentally sound and/or off grid, so modern climate control might be less of a concern? That said, who knows? Not me!

 

[winegamd]

Tiny houses probably just use window units since they are not as concerned with sound proofing.

 

[beans-on-toast]

Mini-splits seem to be common for those that want to cool their tiny house. Found a couple of tiny house studios, not a lot of details.

 

[silky smoove]

I'm not sure I was clear

Oh no, you were perfectly clear, and it's definitely a good idea, but it comes with some drawbacks that are outweighed by the convenience of having everything in one package. Most notably a few extra wall penetrations. On that front you were correct that it wouldn't make a ton of difference to the isolation perimeter, but in a game of inches, I'll take all of the help I can get in terms of maintaining the isolation perimeter. The other downside to this that I haven't gone into detail about in this thread, save for a mention about 20-some pages ago, is what I have planned for the area adjacent to where the exterior unit will live. One of these larger, all-in-one units would preclude construction of my next project which will be just north of the studio.

Who would have thought that the cost of HVAC and electrical would approach the cost of the building.

I think it's going to be okay after watching some installation videos of a mini split system. I'm confident in my ability to do it myself, save for the pressure test, purge, and refrigerant vacuum portion. I'm now budgeting $2,000 for the HVAC. The electrical is still a mystery since my electrician pulled a no-show and I haven't rescheduled. He's done work on my house before, so I know he's good, but as such he's in high demand, and evidently not very good at communicating/scheduling. I'm throwing a wild guess of $5,000 for the electrical, but hopefully it's cheaper. Either way, the HVAC and electrical should only amount to about half of what was originally quoted for HVAC alone.

The tiny house community is pushing a lot of boundaries. Perhaps they have useful HVAC solutions. Tiny house studios?

Both of my fellow Washington-state'ers answered this as well as I could.

Probably not, the requirements, as silky pointed out, are completely different. Not to mention it seems like a lot of the impetus for the tiny house movement is to be environmentally sound and/or off grid, so modern climate control might be less of a concern? That said, who knows? Not me!

Tiny houses probably just use window units since they are not as concerned with sound proofing.

 

[beans-on-toast]

I think it's going to be okay after watching some installation videos of a mini split system

I saw this installation on This Old House. The unit came precharged but they still had to pressure test the external lines. They glanced over how to properly bend the lines without kinking them. There are simple tools for that, like brake line benders.


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[silky smoove]

That was one of the first videos I watched on the topic. I've found others that get into more specifics about using the flare wrench and not kinking the copper line.

 

[beans-on-toast]

The valves on the unit in the video make charging easier. I'd want them on any new system. On my home AC, there's a small tube that's simply crimped to seal it. Not the best way to do it but not uncommon.

 

[silky smoove]

Looks like my BTU/h need is around 8,000. That doesn't account for oversizing to allow for lower fan speeds (i.e. running a larger unit on a lower setting for quieter operation while achieving comparable heating/cooling), but it's a good starting point. Here's an example of a 12,000 BTU model that's floor-mounted, has an extended warranty (that you pay for of course), and all of the required extra "stuff". This is the first one I've priced, but at the very least coming in just under $2,000 is encouraging.

 

[beans-on-toast]

It's difficult to evaluate the noise specs of mini-splits. They can get creative when evaluating their products. Some stores have them set up and running so can see and hear what they can do. A very good studio HVAC system will be around 10dBA but I doubt that you can find a mini-split that can come close to that.

220VAC vs 120VAC is another consideration.


Microphone noise levels according to Neumann:

WHAT’S A GOOD SELF-NOISE FIGURE?
Anything below 10 dB-A is extremely low noise. The exact figure is unimportant, as even a very quiet recording room will contribute quite a bit more ambient noise than 10 dB-A. Typically, extremely low self-noise figures are only found on modern day large diaphragm condenser mics, such as the Neumann TLM 103.

11-15 dB-A is still very good. You may be able to discern some very slight noise in critical applications. But usually, such noise is impossible to hear in the context of the whole mix. 11-15 dB-A is about as low a self-noise figure as you’ll find on a small diaphragm condenser (such as the Neumann KM 184) or an excellent large diaphragm condenser with tube electronics (such as the Neumann M 149 Tube).

16-19 dB-A is good enough for most purposes. You may hear some noise when you record relatively quiet instruments, but it’s usually unobtrusive.

20-23 dB-A is a pretty high self-noise figure for a studio microphone. This is an area where every decibel counts, because we’ve reached a noise level that’s clearly audible. Such noise figures may be acceptable when you record loud sources, but not for anything below speaking level.

24 dB-A and above: Such self-noise figures are unworthy of a studio microphone.

Self-noise is rarely specified for dynamic microphones. That’s because their noise performance is largely dependent on the microphone preamp used. As a rule of thumb: Dynamic microphones on an ultra-low noise preamp reach self-noise figures of about 18 dB-A.