On Purpose Productions detached garage studio

Sandersd wrote:

Flex duct is not a good choice for long runs as it has a high friction coefficient. A better choice is to fabricate out of ductboard or use insulated sheet metal ducts. My best advice is to keep researching until you thoroughly understand how a system goes together and what materials work best under what conditions. Then you can evaluate any recommendations by HVAC contractors based on your specific needs. Reference: http://www.toolbase.org/PDF/DesignGuide ... ystems.pdf http://www.bookmarki.com/Bob-s-House-Un ... 765373.htm http://www.standexadp.com/install.htm http://www.bookmarki.com/Manual-D-Resid ... 765500.htm http://www.acca.org/store/product.php?pid=318 http://www.hvaccomputer.com/gtarget1.as ... DQod820_Qw http://www.energy.ca.gov/efficiency/qua ... dures.html http://www.engineeringtoolbox.com/hvac- ... -t_23.html http://ducts.lbl.gov/ http://www.toolbase.org/ToolbaseResourc ... tegoryID=6

Hi Sanders, Thanks for chimmin' in and for the great links. I did wrestle with whether or not to use the flexduct. I have discussed with my contractor the issue of increased back-pressure due to sagging of the duct, and the possibility of the HRV automatically switching up to a higher setting as a result. He also spoke to the supplier about my particular install and special requirements. As of right now, I feel okay about going ahead with it but since my contractor just went away for two weeks I've got some time to examine things a little more - I'm definitely going to read through those links! - Greg

Sandersd wrote:

Make sure you use pressure treated lumber and a foam seal under the bottom plates or anywhere else wood contacts concrete. Wood + concrete = rot.

Well - I ended up using the foam strip but I didn't use pressure-treated lumber for the foot plate. I probably should have. I GOT MY PERMIT TODAY!!!!! Man! It took 3 incredibly frustrating and nerve-racking months but now its all official! :D :D

Update! It's been far too long since I last posted and I have achieved a few things. Here's pics and descrips; Pic 1&2 - Because the existing door at the back of the garage opens into the room I had to raise it to get the subfloor installed. But since I'll be building a frame that spans the outer and inner walls (inner walls not built yet) I ended up pulling out the door and frame, raising it and putting the existing door back on temporarily. The sill was actually leaking pretty bad before and getting the surrounding studs wet on the inside so I also fixed that while I was at it. I then also finished off the drywall 'beef' and insulation in the surrounding stud cavities. Pics 3,4,5&6 - In order to cut out the new doorway on the side of the garage, which will be the main entrance, I had to excavate an area on the outside and install a retaining wall. Before and after pics. I'll be putting down some flagstone and we'll pretty things up with some planters on top of the wall. More to follow....

and more.... Pics 1-3 - After supporting the ceiling truss temporarily I cut out the opening for the new doorway with a reciprocating saw for the wood and circular saw with masonry blade for the cinder block. I scored the block and then hammered it out. On the one side I broke out too much block and had to fill it back in with mortar. You can also see the finished outer leaf wall in front of the garage door. And the Dricore subfloor system just went in recently with the help of a friend. I'll likely use tapcom screws in places where its not down snug on the concrete. There's a 1/4" gap around the perimeter where I plan to put backer rod and acoustic caulk before building the inner leaf walls. Pics 4-6 - The HVAC contractor installed the HRV in the attic as well as the flexduct (which I decided to stick with) and the rough runs for the mini-split. They put the intake and exhaust ports in the gable end of the attic. I plan on building a silencer box to go on both the supply and exhaust ports of the live room but not on the ports for the control room. I'll be posting my plans shortly to get some feedback. more to come.... :D

looking good :)

John Sayers wrote:

looking good :)

Hey, thanks John! More pics and descrips; Pics 1&2 - Just yesterday I cut out and built an attic access door in the gable end (access from exterior) for servicing the HRV. It still needs to be painted, weatherstripped, trimmed and caulked on the outside and a doorstop on the inside. Having the access point in the gable end means I don't have to penetrate my layers of soundproofing :wink: Pics 3&4 - This is the design of the silencer box that I'll likely be building very soon. I would build two, putting one on each port in the live room. The second pic attempts to show how I plan to position them. Half of the trap is above the outer leaf with the flexduct attaching directly into the side. The bottom would be flush with the lower edge of the inner ceiling studs so that the finish drywall would actually go right up against the bottom of the trap. The dimensions of the trap makes a 14"x14" square which allows it to sit in between the 16"OC inner ceiling studs without touching them. I'll likely use 1/2" OSB for the outside of the box and 5/8" duct liner covering the inside. Honestly, I've wondered whether I actually need the silencers or not. The flexduct isn't going to carry sound well at all and there is quite a bit of length with many bends as it is. And of course, adding the silencer would really increase the restriction of air flow which may result in the HRV having to switch to its 'high' speed. I'm not really concerned with leakage from the live room to the control room but rather leakage from the live room outside. But I just don't know....Any thoughts?

pics and descrips (sorry for the blurry pics :oops: ); 1. I Installed a flexible conduit (FlexPlus Blue ENT) through the soffit on the exterior, through the attic space and ending at what will be my equipment room. This conduit is for the cable company to run their coaxial line into the studio for phone and internet. 2. I completed the attic access door. 3-5. I built the duct silencer boxes using 1/2" OSB and 1/2" duct liner.

and more..... 1. I temporarily installed one of the silencers and powered up the HRV to test airflow. True to what I've heard, the HRV is essentially silent when on its low speed. And I was really happy with the velocity of flow on the exhaust port, which is what I hooked the silencer up to. :yahoo: I think I might wrap the silencers in 2 layers of drywall on all sides once they're fully installed. That should minimize sound traveling through the walls of the silencer into the attic, and out to my neighbors. 2. I got the 13 sheets of OSB and 26 sheets of drywall required to close in the ceiling. That's going to be a lot of work and it starts in about 5 minutes!!

Looking Good. where did you buy the duct liner from?? I having trouble finding it.

petrovinksy wrote:

Looking Good. where did you buy the duct liner from?? I having trouble finding it.

North York Plumbing & Heating in Aurora. They have 4' wide rolls of 1/2" and 1" in their shop for their own use. I don't think they usually sell it to the public. They charged me $2.00 per square foot and I needed 12. I'm sure one of the larger plumbing and heating shops in Hamilton should have some.....

moving right along..... Pic 1. The OSB starts going in. I tried to make my cuts a tight fit so I often had to use a planer shave edges here and there. Pic 2. Since I was a one-man crew putting up the OSB I put together this simple frame to hold up one end of the sheet while I held and screwed the other. Worked like a charm! Pic 3. Gettin' there. I sanded down the edges of the duct cut-outs and wrapped them in aluminum tape to protect the flex duct. Pic 4. I ended up covering the portion of the silencers that would be above my outer leaf with one layer of drywall. Pic 5. Once the OSB was up I caulked around the bottom edge with acoustical caulk. Pic 6. Done! I wasn't planning on caulking any of this layer but there are a few large gaps that I'll probably fill with some backer rod and caulk before starting on the drywall layers. One thing I really noticed while closing in the ceiling was how hot it gets in the attic when the sun is out. WOW! It made me wonder whether I should be adding a couple more vents in the outermost layer of the ceiling. There's only one currently for the just under 400 sq ft garage....I mean....studio :) I'll possibly add these from the outside the first time the shingles are replaced. That also made me wonder how much coolness will be lost through the run of refrigerant pipe that runs approx. 15 ft. through the attic? Although it is wrapped in an insulator...

Looks great, Im in the same process of putting my OSB up now too, and cutting around those damn trusses, sure does get hot up there huh? Loving the silencer too, u have inspired me to do my own, great work.

Hey Luv, Thanks a lot for the kind words. I've read through your thread as well - you've got an amazing space and I dig your layout. I had really been hoping for a space more that size but compromised in order to stay within town. Ultimately I feel incredibly blessed with what I've got. Yeah - cutting that OSB to fit snug between the studs was fun! Are you working mostly by yourself as well? Actually, In cutting the OSB I encountered my first consequence of buying cheap tools (I noticed you have a sweet Dewalt miter saw). My Ryobi 7.5" handheld circular saw started going all wobbly during cuts making it impossible to cut a straight edge. I've only had it since Christmas! I had to switch to my Ryobi jigsaw (also the cheapest I could get :roll: ) about 1/3 the way through the job. Oh well.....you do what you can.

Question: While closing in my ceiling and feeling how hot it gets up in the attic when the sun is out I started thinking about the wisdom of my mini split refrigerant lines running through the attic. It seems that in the summer I'll be running my refrigerant through an oven to get to the air handler unit and in the winter the pipes might be freezing.... Its possible to still pull them down at this point and I could probably run them within the 1" gap between my outer and inner leaf ceilings. In that case the insulated sleeves would be compressed a bit between each leaf but I'd think that would be fine. Any thoughts?

Hey Onpurp, I'm pretty much working by myself as you are, not too fun when its comes to getting those sheets up there. I'm actually in the same boat you are, since the dewalt only cuts about 12" across, so all mine have been done with the circular saw as well, ill tell you what tho, I went through 4 reciprocating saws just trying to tear the floor up!! :shock: Not too mention the dewalt is on loan from my uncle. But again the place looks great, maybe you can give me some pointers if i get caught in a bind. Keep those pics coming!! Ian

NativeLuv17 wrote:

maybe you can give me some pointers if i get caught in a bind.

I certainly will if I can. I'm Greg by the way.

Nice work Greg - and I thank you for sharing your experiences building that damn studio :). cheers john

Those are damn kind words John! Although it was Ian who brought out the 'damn' :wink: I'm actually considering a significant change to my layout. I've been really concerned that the control room is going to feel cramped and tiny. I've been wondering whether I should do away with the small room to the right of my mix position which was to be my equipment room. This would allow me an extra 2 feet of width in the control room. In this case I would use the one remaining closet as my equipment/mic/everything else closet. I'd probably have just enough room to get behind the equipment rack in that little closet... However, this brings the width and length dimensions of the CR really close to square, even though the walls are angled and I plan on building a large cloud panel above the console that will effectively angle that part of the ceiling. I've been mulling this over for quite some time and I'm really torn. Framing isn't far off so I've got to make a decision!

I plan on building a large cloud panel above the console that will effectively angle that part of the ceiling.

The cloud won't change the room ratio, though! The dimensions of the room for figuring your ratio are taken from the finished interior hard surfaces of the walls. IE, from the inner leaf walls, floor and ceiling. Not from any acoustic treatment that you might have attached of those. The reason is because room modes are related to the standing waves that form between those boundary surfaces, and the most important (most detrimental) waves are low frequency waves, which implies long wavelengths. Waves are not affected much by objects that are smaller than the wavelength, and the waves just "wrap" around those relatively small objects. At the low end, wavelengths are around 1.7 to 17 meters. So anything smaller than that just isn't really visible to the wave, which includes most types of acoustic treatment. A cloud isn't really big enough (in terms of relationship to wavelengths) to have much effect on room modes. It does absorb mids and highs, though, which is what you want it to do. But it does not change your room dimensions. - Stuart -

However, this brings the width and length dimensions of the CR really close to square, even though the walls are angled

Try nudging the walls a bit, here and there, until you get close to a good ratio, then stick with that. You could slide over the let hand wall of your CR towards the right just a little, to improve your ratio and get you more space in both your LR and your rack closet. You could also move that wall between your rack closet and live room up the page a little, to give you more room in there. From decades of personal experience designing and installing video post facilities, I can tell you that you do NOT want to have a rack where there is barely enough room behind it to stand up behind it!!! Give yourself plenty of room behind the rack, or cabling it will be a nightmare. Also, do yourself a huge favor, and permanently install a couple of long strip lights (tubes) vertically up the corners behind the rack, to give you plenty of light while you work there. Get the kind that has both a transparent plastic cover and also a metal mesh grill over the front, so you don't break them while moving around... I learned that trick from the smartest video engineer I ever met, many years ago. And don't forget to allow for HVAC in that rack closet! Real small space, lots of equipment.... Heat will build real fast in there. - Stuart -

Soundman2020 wrote:

I plan on building a large cloud panel above the console that will effectively angle that part of the ceiling.

The cloud won't change the room ratio, though!

Hey Stuart - thanks for the thoughts. I'm not so sure a cloud panel wouldn't have any impact on room nodes though. I mean, I agree with all the acoustic principles you referred to but if we go strictly by those principles then technically the walls of my control room would also not be 'visible' by those lowest, most troublesome frequencies either. But the walls do have some impact (increasingly so with greater amounts of mass) and so we calculate at which frequencies that degree of impact will be at. So if my cloud is really just comprised of mineral wool and breathable fabric than it will certainly have very minimal impact but if I make it with walls of some reasonable amount of mass - more like a bass trap panel..... What do you think?

Soundman2020 wrote:

You could slide over the let hand wall of your CR towards the right just a little, to improve your ratio and get you more space in both your LR and your rack closet.

Actually, if I only move that wall to the right just a little it would actually make the room more square. I'd probably have to move it towards the left, making the closet and booth even smaller. :(

Soundman2020 wrote:

Give yourself plenty of room behind the rack, or cabling it will be a nightmare.

If that little closet did become the equipment room than I'd hopefully be able to wheel the rack out part way through the doorway in order to get more wiggle room. It certainly will still be tight though. That's one of the compromises of this layout for sure.

Soundman2020 wrote:

And don't forget to allow for HVAC in that rack closet! Real small space, lots of equipment.... Heat will build real fast in there.

Unfortunately, getting conditioned air into my equipment room was never going to be an option. Since I'm using a mini-split I'd have to add a third air handler to the system, which would make a crazy expensive system a ridiculously expensive one. So opening the door when possible will be the system of cooling the equipment room :( Thanks a tonne for your thoughts Stuart! It's been a while since I had some.

I mean, I agree with all the acoustic principles you referred to but if we go strictly by those principles then technically the walls of my control room would also not be 'visible' by those lowest, most troublesome frequencies either.

Actually no, because the MSM wall works on an entirely different principle. It is a tuned system. Technically it is a bandpass filter that is tuned to the resonant frequency of the wall system. At the resonant frequency it is not only transparent to sound, but actually boosts sound through the wall. At frequencies above and below resonance, it blocks sound progressively better. Since the resonant frequency of your wall is designed to be as low as possible, and hopefully outside of the range of human hearing, it blocks all of the frequencies that are of concern to us humans. The walls of your studio will only be visible to the low frequencies if you build them wrong! For example, if you don't put enough mass into the walls, or have an air gap that is too small, or don't put enough fiberglass inside the cavity, then the resonant frequency will, indeed, be high enough that your wall will pass sound at frequencies where you don't want it to. But that isn't related at all to the issue of sound bending around objects whose dimensions are smaller than the wavelength. That's an entirely different thing. In any event, since your studio is supposed to be sealed airtight, waves are not able to "bend around" the walls, since they are prevented from doing so by the walls themselves. The walls. floor and ceiling define the acoustic boundaries of the room. So in order for your cloud to be able to change the room modes, you would have to build it from wall to wall, and seal it airtight to the walls. But then it would be a ceiling, and would no longer be a cloud!! :)

I'm not so sure a cloud panel wouldn't have any impact on room nodes though.

If you build the cloud large enough and massive enough then it might, indeed, add new modes to the room. But it will not affect existing modes, since they are defined by the room boundaries, not by objects within it.

So if my cloud is really just comprised of mineral wool and breathable fabric than it will certainly have very minimal impact but if I make it with walls of some reasonable amount of mass - more like a bass trap panel.....

Then it would be a bass trap AND a ceiling cloud! :) But it still would not have any effect on your room ratio, nor on the modes that are defined by the room boundaries, except perhaps to add a few more modes of its own. In order to change your room ratio, you have to change your room dimensions, and that means moving one of the bounding surfaces of the room.

Actually, if I only move that wall to the right just a little it would actually make the room more square.

You mean that right now it is wider than it is long? That means that you are firing your speakers along the shorter axis of the room, instead of the longer axis? If that's the case, then maybe you should rotate the room 90°, so that you can get the speakers firing down the long axis again. - Stuart -

Soundman2020 wrote:

Actually, if I only move that wall to the right just a little it would actually make the room more square.

You mean that right now it is wider than it is long? That means that you are firing your speakers along the shorter axis of the room, instead of the longer axis? If that's the case, then maybe you should rotate the room 90°, so that you can get the speakers firing down the long axis again.

{insert hand smacking forehead smiley} - I spoke to quick. I was really just considering the widest part of the room against the length. If I took a rough average from the widest and the narrowest to get the width then I'd have the following dimensions: H - 7' 7" W - 11' 8.75" L - 12' 5" A ratio of 1 : 1.55 : 1.64 Not all that great. My layout with the equipment room had a CR ratio of 1 : 1.3 : 1.65, which is actually quite close to Sepmeyer's second ideal room ratio. This is the decision I have: an ideal room ratio that may potentially feel small and cramped or more space with the likelihood of increased modal issues. I could move the wall between the booth and CR in as you suggested. If I move it 3" I'd end up with a 1 : 1.5 : 1.64 ratio - not a major improvement. If I move it more than I'm starting to defeat the purpose of the alteration. Compromise is the name of the game I'm playing.....maybe installing some drywall will clear my head :?

First layer of drywall and backer rod is up. Time for caulking again. I used up my first 2100' of backer rod about half way through the ceiling. I did end up pulling down the refrigerant lines from the attic. Once the outer leaf ceiling is complete I'll attach them to the bottom of the lower truss chord. Hopefully they won't be too much of a pain to work around when building the inner leaf ceiling. We'll see...