FINISHED IN 2020! Sharward's Partial Garage Conversion

sharward wrote:

Several of us are on the verge of installing fresh air ventilation systems and silencers, so hopefully this area will abe more effectively covered once we have them up and running with all the requisite pictures to go with them. 8)

I agree. There is far too little information on how to do it right here. I've been guessing most of my way out of doing mine. :roll: Congratulations on the mini-split. I just finished mine, and it is a great feeling. :)

Hey andyroo! Almost DT time! 8) Post pictures of your mini split system! We need a Mini Split Hall of Fame! :twisted:

Keith, What are you going to put in the gap between slabs? Does Rod recommend anything?

I don't have anything but air around my new slab, but I did cover the gap with a premium grade (Shaw brand) three-in-one laminate floor underlayment material that acts as a capilary break under the soleplates of my inner leaf wall frames. I used two beads of GE Silicone II caulk under the frames and along the outer foundation as a seal, plus I used a staple gun to hold the material up along the outer leaf so as to keep gravity from eventually peeling the material away from the caulk. The material has anti-fungal properties too. It's an unorthodox method, I'm sure, and it wasn't cheap, but I felt better about that than I would have using ordinary plastic sheeting. I took pictures - they're buried in this thread somewhere... In other news... I didn't report this before, but I had another snafu with the mini split: again it lost its cooling luster, so I again feared a leak in the system somewhere, bracing for the worst. Ends up it was just another bad connection on one of the refrigerant line flare connections behind the indoor unit. My tech tightened it up and tested both connections for leaks very thoroughly this time. Whereas before the fix the unit was pumping air through that was about 10°F cooler than what was being sucked in, after the fix it is about 28°F cooler! :twisted: Moral of the story: make the tech follow the instruction manual to the letter, and make that a part of your agreement ahead of time! If he had followed the documented procedures by tightening the connections to the specified torque and used the liquid soapy stuff to look for leaks on day one, it would have saved him two return trips and me a lot of worry! I just returned from four concerts over six days -- all three California Dream Theater / Redemption shows (San Diego, Hollywood, and Berkeley), plus Symphony X in San Francisco. :twisted: What an(other) awesome experience. I won't bore you with details, but suffice it to say that I'm pumped with inspiration and motivation to get this damned room finished so I can play! :twisted:

I was pretty lazy this weekend... It seems the energy I expended during my trip and concerts caught up with me. But I did drag myself to Home De(s)pot to purchase some stuff with which I'll be making my fresh air ventilation silencers. I've been testing the mini split every few days, and it's been running great with 25°F+ degree differentials. I really think there are no more leaks! Hopefully I'll have something worthwhile to report in the next week or two. --Keith :mrgreen:

Hey Keith, I'm waiting for more information on how you're going to do your ductwork. I'm really worried about compromising the integrity of my room.

I wish I had something to report. Unfortunately, all I have to report is that I have nothing to report. :-( We're in the midst of a big upgrade at work, so I couldn't work on my studio this weekend at all as I had hoped/planned. :x Hopefully I'll be able to accomplish something next weekend. Well, truth be told, I did cut some OSB and timber last weekend for a few hours -- pieces of what will become my silencers -- but there's nothing photogenic yet. :roll: --Keith :mrgreen:

OK, finally -- something to report, with photos! 8) I'm done with one of my silencers and I'm working on my second one now. It will be a virtual twin of the first. I hope this design will work -- I'm always one to jump on people who "guess" at solutions, but I have to admit that's what I'm doing in this case! :oops: I think and hope that I'm "overkilling" in a lot of ways that any shortcomings with this design will be compensated for and that this won't be a major "weak link" in my overall design... :roll: So, to recap a bit -- I had originally intended to have four very large (about 8' x 2' x 1') silencer boxes: two on the inner leaf and two on the outer leaf, two for incoming fresh air and two for outgoing exhaust air. These silencers would have looked like soffits along the ceiling in the back and front of the room. I decided along the way that would be too much work for me... :roll: ...and I've seen some examples and read some accounts of people building their silencers into their ceilings between ceiling joists. :idea: I decided to give that a shot. I also decided that I would try to get away with silencers only on my inner leaf. Since the ducting will be running into my attic, I figure that if I need silencers added to the outer leaf, I can build them later inside the attic where the ducting comes in from the studio. This would not be ideal, but I can do it if I must. The prospect of building them inside the attic is daunting, as getting the materials fed up into the attic space and assembled there (as I expect they would be too heavy to attempt to push up, especially working solo as I usually do) is not something I look forward to, so I am cautiously optimistic that it won't be necessary... :roll: I started out with a piece of 2' x 4' OSB, plus two sections of of 4' x 16" x 5/8" drywall screwed to it, with a fair amount of Green Glue sandwiched between each layer (OSB-GG-DW-GG-DW). I then took a couple of 9" x nearly 4' long strips of OSB and screwed them to some 4 foot long 2x4s, using Green Glue in the hopes of minimizing sustained resonance. I had to get "jiggy" with the jigsaw for this piece... I cut a 9" round hole into the outer leaf ceiling, fed through an 8" wide insulated flex duct, attached it to a very nice galvanized ducting elbow connector that smoothly transitions an 8" round duct to a rectangle measuring 12" x 3 1/4", using metallic duct tape along the way: Here's the silencer box sealed on the inside with acoustic sealant, using a putty knife to ensure a good "bite" to the OSB. This box is designed to hopefully "keep up" with the mass and isolation properties of the rest of the build. The box is nearly 4 feet long and measures about 9" high and about 13 1/2" wide. With the inner ceiling and the outer ceiling and the top of the box in between, that's three leaves, folks! :roll: ...But, as I understand it, it's pretty much impossible to build a silencer without creeping into three-leaf territory -- we just try to minimize it where we can and make up for it as best we can along the way, right? :? I then stuffed two batts of 3" thick Thermafiber SAFB (2.5#psf) into the top of the box, then used some plastic sheeting left over from my concrete pour to cover it up. This ensures that the fibers from the insulation won't break loose, and I think it will also provide a smooth surface for air to flow by, thereby reducing friction / static pressure. I also attached a register box that starts out with the same size opening as the piece on the other end (12" x 3 1/4"), which then makes a smooth elbow down to a generous 12" x 8" register opening. This side view is probably easier to follow -- you can see where the duct enters the outer leaf ceiling on the far right. I'm more than halfway through the second one now, as many of the pieces I had to cut for the first were cut at the same time as the second. Note that the fresh air ventilation system I have has 6" ports, so I'll need to reduce the 8" flex duct down to 6", probably as close as possible to the unit. The distance from unit to studio will be very close (laundry room adjacent to studio). I will try to keep the ducts as straight as possible with bends that sweep as gently as possible. My hope is that the 3 feet or so of 6" thick Thermafiber SAFB insulation that the sound will pass below prior to exiting the room will absorb at least some/most of the sound before it arrives at the penetration! :!: I'm almost afraid to ask, but any feedback from the pros would be appreciated before I paint myself too tightly into this corner! :shock: Thanks all, --Keith :mrgreen:

i'm no expert, but my first impression is that you might want tar paper lining the inside of the osb box. i remember something about this from paul's studio build, i think it was a suggestion from eric. something about moisture control. also, wouldn't fabric work better than the PE film you're using? the low freq waves will still get to the rockwool to be absorbed, but high ones might just reflect off the plastic and into(or out of) your studio. what you've got looks good, i hope someone with more expertise chimes in to help a bit. silencer boxes are a gray area round these forums. I was disappointed that rod didn't include anything about them in his book.

Hi Keith, Nice to see your progress. I know it's hot these days in Sactown. I also think the plastic is an odd choice. Isn't the rule that you want to use fabric you can easily blow through to cover up acoustic treatments? I used grey lanscaping cloth from home depot. It might be better to use something like that. It's very tough stuff, easy to use, you can staple it and it won't tear away. It's fine enough mesh to stop fibers (i think so anyway) but you can blow air right through it. I think i have a picture of the label somewhere in my thread. Dan

Use John Mansville Duct Liner - it has a black polymer coating and that was a part of the assembly when they tested it acoustically - The plastic is a bad move- and will increase air noise....... Rod

OK, cool -- thanks for the input guys. I'll see if I can get my hands on the duct liner.

By the way, I just wanted to say I had figured on using the plastic since I assumed low end TL was my biggest concern and that I might be able to afford a bit of high end TL inferiority in favor of using a material I had on hand and that was sure to not deteriorate over time... I must confess that I'm getting a bit of Why The Hell Am I Not Done With This Damned Thing fever and the temptation to Just Get The Damned Thing Built Already is calling out to me! :shock: :roll: :? :oops: But, I'm not fighting the advice I'm being given, so on I go with my quest to acquire The Proper Materials For the Job At Hand! ;-) Thanks to all who have responded. Dan, it's good to see you're still tuned in! 8) Now then... Which of these Johns Manville products is the one I need to get my hands on, and in what thickness?

• New! LinaTex™ - Textile Fiber Duct Liner
• Linacoustic RC™ - Fiberglass Duct Liner w/ reinforced coating system
• Permacote® Linacoustic® R-300 - Rigid Fiber Glass Plenum Liner Board
• Permacote® Linacoustic® HP - Fiber Glass Duct Liner

...and can anyone recommend an online source for a small quantity? :roll: And also, to clarify -- I'll be covering the 6" of Thermafiber that I have stuffed at the top of the silencer boxes with this stuff -- right? And... Should I also line the sides and bottom of the boxes with it as well? In the event that the Johns Manville product is not available to me locally or online in a small quantity, is there an equivalent/competitive product I might be able to substitute? --Keith :mrgreen:

keith your doing good dont rush it now. it will be worth it in the end mate.

sharward wrote:

Now then... Which of these Johns Manville products is the one I need to get my hands on, and in what thickness?

• New! LinaTex™ - Textile Fiber Duct Liner
• Linacoustic RC™ - Fiberglass Duct Liner w/ reinforced coating system
• Permacote® Linacoustic® R-300 - Rigid Fiber Glass Plenum Liner Board
• Permacote® Linacoustic® HP - Fiber Glass Duct Liner

...and can anyone recommend an online source for a small quantity? :roll:

Any of the last 3 should be fine - I am not familiar ith the first. 1 1/2" thick is hat I ecommend......... if you have an HVAC contractor - that is a sure bet - just buy it through him.......... if not - CALL THE MANUFACTURER.......... tell them your story and ask them here you should go - you would be surprised - JM even has some distrobutors that they will let you buy from even though you aren't in the biz........

And also, to clarify -- I'll be covering the 6" of Thermafiber that I have stuffed at the top of the silencer boxes with this stuff -- right? And... Should I also line the sides and bottom of the boxes with it as well?

I would remove what you have and substitute this for it - unless you really went overboard with your sizing - your clear space inside per linear foot of run shuld be a minimum of double your duct size feeding it........

In the event that the Johns Manville product is not available to me locally or online in a small quantity, is there an equivalent/competitive product I might be able to substitute?

Always preparing for the worse............ oh well.......... Any duct liner from any manufacturer - as long as it is black faced polymer lined - should be sufficient................ they are really all fairly comparable in that respect.............. rOD

I'd like to make sure the goal of the silencers is clear: to maximize transmission loss (TL). I don't care very much about a little noise from the air movement through the registers. I'm surprised that just having a large empty box lined with the JM duct liner is sufficient to do that. I thought I'd need to have fairly thick absorbtion material inside the box. I had been wondering if 6" (more like 5¼") of mineral wool across the top of the box would be sufficient -- and now it seems I'll going in the opposite direction -- less absorbtion, more open space... :? Granted, the duct liner acts as an absorber -- I'm just surprised that the absorbtion properties of the liner is better than thick mineral wool. Rod, you mentioned lab reports -- where might I find those? I'd like to study this more. I'm surprised this hasn't come up on this forum before... :? --Keith :mrgreen:

sharward wrote:

I'd like to make sure the goal of the silencers is clear: to maximize transmission loss (TL). I don't care very much about a little noise from the air movement through the registers. I'm surprised that just having a large empty box lined with the JM duct liner is sufficient to do that. I thought I'd need to have fairly thick absorbtion material inside the box. I had been wondering if 6" (more like 5¼") of mineral wool across the top of the box would be sufficient -- and now it seems I'll going in the opposite direction -- less absorbtion, more open space... :? Granted, the duct liner acts as an absorber -- I'm just surprised that the absorbtion properties of the liner is better than thick mineral wool. Rod, you mentioned lab reports -- where might I find those? I'd like to study this more. I'm surprised this hasn't come up on this forum before... :?

Keith, you're talking apples and oranges here.......... if outside noise getting into the room via the duct is an issue - then first you build a box based on the MAM system - and INSIDE of the stud cavity you use regular fluffy insulation (unless rockwool is just so much cheaper) because rockwool doesn't really add much if anything to the isolation equation. But - once you are done that - you have to deal with sounds traveling through the duct itself - and THAT is what the baffle system inside the box is dealing with - that and that alone......... The treatments you add inside your room don't do a whole lot for isolation from the outside world - they only help to attenuate that which exists within the room itself - the same goes for the box. Just go to the namufacturer's sites - they all list the test results for each of their materials........ For example- linacoustic: http://www.jm.com/insulation/performanc ... tic_rc.pdf Rod

Thanks for the clarification, Rod. I think I'm getting this. I do understand (and have understood for some time now, thankfully :-)) the fundamentals of Mass-Air-Mass, where the amount of mass in the leaves, their resonance frequencies, dampening that resonance (perhaps with the help of constrained layer dampening, such as Green Glue), and the depth of the air gap, all come into play. What I didn't (and may not still? ;-)) understand was how silencers are supposed to work. What I'm now hearing from you is that using a duct liner product, such as Johns Manville Permacote® Linacoustic® R-300 Rigid Fiber Glass Plenum Liner Board, or a competing product I discovered, Knauf Rigid Plenum Liner, is advised, and (this is key) the more lined surface area the air is exposed to, the better the silencer will perform. Do I have that right? If so, the surface area inside the silencer will be around 6" x 10½" x 32". I need to be sure this is a sufficient volume of surface area that will work for my needs. If it is not, I can afford the space to have the silencer drop down into the room, thus increasing that 6" height to 12" or perhaps taller if needed. I'd rather not, as I think the room will look better with a flat ceiling, plus the drywall and finishing will be easier to complete if it's flat... But I'm willing to do it if it is necessary. I'm currently waiting on a callback from [url=http://www.a-m-s[/url]Acoustical Material Services[/url] (their Sacramento area location is now 3.3 miles from my house :twisted:). They don't stock those products but they think they can order some for me. --Keith :mrgreen:

Phooey... I haven't heard back from AMS or the other place I called... :evil:

Keith, basically you want the free area (volume) inside the box to be double that of the supply to the box itelf........ Rod

I finally heard back from one place, saying they can't get their hands on Johns Manville Permacote® Linacoustic® R-300 Rigid Fiber Glass Plenum Liner Board. The other place hasn't called me back yet and I'm not confident. Ends up that I just discovered while surfing around the Johns Manville Web site that Permacote® Linacoustic® is discontinued, being replaced by Linacoustic RC™. Excerpt: "If you have a job with Permacote Linacoustic specified, don’t worry. Linacoustic RC is the perfect replacement. It’s virtually interchangeable with Permacote Linacoustic and, in some instances, actually superior." So it looks as though I'll be restarting my search for a local(ish) supplier of Linacoustic RC™ - Fiber Glass Duct Liner With Reinforced Coating System -- indeed, the exact "example" product that Rod told me to look at in the first place! :roll: --Keith :mrgreen:

hello mate hope all is well. have you got any further with your silencers and fresh air system?

Hey everyone, I've been so busy with work and distracted by other family-related things lately. Plus I've taken up tennis again and that's taking up some of my weekend morning time lately. Good exercise and lots of fun with the folks I've met playing here. I haven't touched anything in my room for about two months. I realize I'm heading right into the holiday season, but I'm going to really try to turn it back on in December and January. I can't believe I'm not done yet. I started this thread in January of 2005! Hopefully I can steal an hour or so during the week to figure out where the heck I can get a small quantity of good quality duct liner. Sorry I've been so absent here. --Keith :mrgreen:

Hey Keith, I had just entered another message in your "Not dead dead..." thread haha! Good 2 c u alive buddy. Now, quick tennis, give up on those extra timespending jobs and start cracking man. Build that studio! haha, no serious. We SHOULD have a live out there.

Merry Christmas (again) Keith! Perhaps your "layoff" on the studio work might be to your advantage. Remember the V cutting tool and PE "rope" (for sealing drywall joints) that I promised you a while back? Well, I still have them sitting a box to send you if your still interested. As to your duct board sourcing problem, I used an OC product (oddly enough called "Duct Board" that, at least until a couple of months ago) was readily available at my local supplier. The only stuff he had in stock we 1" thick and foil backed but I believe it's also available in 1 1/2" and 2". If you can find my thread, near the end of it, you can see the little "elbows" I made from the stuff for my send/return vents in the control room. It comes is 4' x 10' lengths and the last time I priced it, it was about $45/sheet (in W. Texas). When I got my original order, it was about $36/sheet so who knows how much it goes for today. My plenums were made from just the duct board (i.e., no plywood outer shell) and work just great! Of course, they are 24" x 24" by almost 30' long (one each for send and return air). If fact the only "problems" I ended up with in the HVAC system were: 1) The loudest sound in the big room is when the relay in the themostat clicks on and off and... 2) I neglected to see if my natural gas line in the building was actually connected to something outside the building. When they came to pressure check it before putting on a meter, it turns out you can pretty much just blow into the pipe. The gas company figures that the pipe collapsed somewhere under ground (on my side of the meter) and that more than likely, when the dentist built his office next to the studio (between me and the meter), it was built directly over my gas line (and was probably severed or capped off) in the process! Since it's illegal (in Texas any way) to build a structure over a functional gas line, they took the easy way out and made it non-functional. I <i>could</i> petition the city to have his building torn down but that would not help much with neighborly relations. The good side of this is that the rooms are so well insulated, a couple of small oil filled electric heaters I got from Walmart warm the place up from 55 degrees or so to a toasty 72 in 30 minutes or so and then they stay at that temp for a long time. Anyway, again, a Merry Christmas to you and your family. Sorry, no virtual turkeys this year! :-) len