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post #1081 of 1186 Old 05-18-2014, 06:11 PM
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I feed about 5 people off my Flexraid media server so my issue is usually upload bandwidth. I've seen three streams of 720p 4mbps work simultaneously at my parents, my brother, my friends... All while wife streaming on out roku and I'm playing on iPad so I have little to complain about. Before the $8 a month Comcast blast upgrade and the upgrades to my server I was lucky to get one stream to work. Now with the i7 in the server, no more 5400rpm WD drives (they are slow) and Comcast blast everything is smooth sailing.
My raid has the Hitachi 5400 HDD... as you can see much slower than my SSD.

Denon 4520ci, (3) JBL 2360As/EV DHA-1s, (3) 1/4 Pie bass bins, MiniDSP 2x4s, (4) Klipsch HIPs, (2) Klipsch KP3002s, PS3, XBox 360, (3) Intel NUCs, Monoprice Redmere, Monster HTPS7000, 2 SUPER SPUD subs, Panasonic AE8000us SeymourAV 180 (195" diagonal) scope screen, Yamaha P7000s (for the subs), (2) Yamaha P2500s amps for the front (3) bass bins.
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post #1082 of 1186 Old 05-19-2014, 05:17 PM
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My raid has the Hitachi 5400 HDD... as you can see much slower than my SSD.

No not really. I think you are stuck in 10/100 mode (the same thing I cautioned Fred about earlier above) because your speed seems to suggest that.

88 207 080 (bits per second) =10.5151033 MB per second

Remember mbps and MB per second are different! I also cautioned about this too.

In 10/100 mode you top out about 10-11MB a second (exactly what you have).

In 10/100/1000 you get gigabit speeds (which is 125MB/sec theoretical, but can be 90-110MB in real life depending on how long your runs are, how many bends in cables, and the quality of your router or switch and LAN cards)

My first suggestion would be check to see if your router is only 10/100 or if your machine or LAN cards are only 10/100 ? You want to invest in a cheap ($20) gigabit switch that is 10/100/1000 is an easy fix to get full network speed. I hate to derail Fred's theater build though, so if you need more help start a thread in the HTPC section and PM me a link and I can help out.

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post #1083 of 1186 Old 05-22-2014, 10:48 AM
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When is the next theater progress update due ? confused.gif

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post #1084 of 1186 Old 05-22-2014, 02:55 PM - Thread Starter
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That's a great question; a question for the ages... If you know what I mean. I don't use the "L" word, but things move at their own pace.

In better news, Plex works great. smile.gif I was always a little frustrated by my Boxee, especially the network functions, so imagine my surprise when Plex practically set itself up and worked with virtually no tweaks. (I've only had a handful of meta-data errors out of many hundred files.) I lent out my Chromecast, but I hope that integrating it in the system will fix me up for a good long while. Actually, now's probably not the time to start into details, but eventually a rack mounted NAS and HTPC sounds like a great option, or maybe a TiVo along with it - but the TiVo makes for too many UIs and interfaces.
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post #1085 of 1186 Old 05-22-2014, 03:03 PM
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When is the next theater progress update due ? confused.gif

Right after you start your theater build thread!!! tongue.gif
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post #1086 of 1186 Old 05-24-2014, 10:28 AM
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Right after you start your theater build thread!!! tongue.gif

Not till I have a plan ! I want to wait till I have the final dimensions, everything is contingent upon that. I'm actually a lot more solid on my ideas and plans for theater than the rest of the house tongue.gif

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post #1087 of 1186 Old 05-27-2014, 02:28 PM
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Quote:
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Right after you start your theater build thread!!! tongue.gif

Quote:
Originally Posted by Mfusick View Post

Not till I have a plan ! I want to wait till I have the final dimensions, everything is contingent upon that. I'm actually a lot more solid on my ideas and plans for theater than the rest of the house tongue.gif
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post #1088 of 1186 Old 06-23-2014, 06:21 PM - Thread Starter
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Wow... a month without a post again. Good news is that I got some more subfloor and GG down on the riser yesterday. Trust me when I say you don't need to see the pictures. There aren't any, but if there were, they would look just like this one, but with an extra layer of subfloor, and may a little GG squeezing out the front.
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post #1089 of 1186 Old 07-02-2014, 09:21 AM - Thread Starter
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Well here's a lesson learned, but not too dearly. I finally got the downstairs HVAC system up and running this morning.

When we initially moved in, the HVAC company explained that there was some goofy wiring, but everything seemed to operate normally. The thermostat that was installed was incompatible in some way (I think it wouldn't run the heat or something), so I removed it long ago. Last week I bought a new thermostat and went to install it. The weird wiring left me unsure that I had done it right, and the compressor didn't come on - so I paid the guy to come back out today and make sure everything got hooked up and still worked.

Turns out that my thermostat wiring was mostly good - I hadn't connected the lead for the emergency heat (which I'll probably never use, but now it's connected and verified), so that's good. The other thing was that the power to the compressor was turned off at the panel, on an unmarked breaker. A little confidence and experience goes a long way. (That's why you hire pro's right?)

I also got an opinion from the guy about how to add my return duct, which has been routed for months, but not connected to the air handler. I was on the fence about how to balance the air pressures. I'm not 100% certain that his suggestion was the absolute answer, but I'll go with his first. The choice is in whether to add a new intake port to the box under the air handler, or just to expand an existing port and replace the duct. Feel free to skip over this net paragraph if you have no patience for mundane details of HVAC - OTOH, if you are a geek for this, here you go...

The basement was initially configured with 6 supply ducts - all flex and all 6" I think - and two return paths - one large grill directly through the wall into the air handler, and one 7" flex duct. The large grill provided return for the theater and adjacent space (the was no wall dividing them) and the 7" duct is in the stairs, providing return for the stairwell and other room; there is no return in the bathroom. Now that the theater area is separated, I've devoted two 6" supply ducts to it, and added one 8" flex duct for return. Since the door that previously separated the two basement areas has been removed, my thought was I could change the hole for the 7" flex to 8" and just get rid of the 7", allowing the single large grill to provide return for everything outside the theater. The alternative is to cut a new 8" hole and leave the 7" in place. I don't think I explained everything well enough to the repair guy, but he said he would add a new hole for the new duct. Can I get an opinion? Do you need a diagram to understand more clearly?

I feel good about this progress, because now I can start to consider the duct boots in the theater more confidently. The registers outside the theater are loud, but the unbooted ducts in the theater are pretty quiet for now - so that's a good start I guess.
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post #1090 of 1186 Old 07-02-2014, 10:38 AM - Thread Starter
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Duct boots: do they need to be built and installed as separate structures?

It seems I could just simply cut a hole int he soffit for the diffuser and call it a day. Probably better than that is to line to boot area with duct liner and install the diffuser. What advantage would building a boot to attach to the end of the flex duct provide? Maybe I just need to seal the duct against something to keep the conditioned air from leaking back into the other areas of the soffit?





I think I just need to seal the duct against something and then line with duct liner. Reasons to do something more involved?
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post #1091 of 1186 Old 07-02-2014, 11:05 AM
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Poorly sealed ductwork is often the most prevelent yet easily solved problem in HVAC and new construction. Duct leakage contributes to 10% to 30% of the heating and cooling loads in many homes. In addition, duct leakage can decrease comfort and endanger health and safety (extreme cases). Duct insullation does not provide an air tight seal. You should use duct sealing mastic with embeded reinforced mesh tape, and do a duct leakage test.

Nontoxic duct sealing mastic or Aluminum tape with UL-181 A or B rating with improved adhesives are slightly more expensive than silver tape but work better.

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post #1092 of 1186 Old 07-02-2014, 08:54 PM
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Quote:
Originally Posted by HopefulFred View Post
Duct boots: do they need to be built and installed as separate structures?

It seems I could just simply cut a hole int he soffit for the diffuser and call it a day. Probably better than that is to line to boot area with duct liner and install the diffuser. What advantage would building a boot to attach to the end of the flex duct provide? Maybe I just need to seal the duct against something to keep the conditioned air from leaking back into the other areas of the soffit?





I think I just need to seal the duct against something and then line with duct liner. Reasons to do something more involved?
Fred, if you seal then you should be fine.......I just built a plywood box, sealed, lined with sheetrock, sealed and lastly, applied Linacousic RC. Flex duct coming into box used appropriate transition with gasket.
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post #1093 of 1186 Old 07-03-2014, 06:16 AM
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post #1094 of 1186 Old 07-03-2014, 06:29 AM - Thread Starter
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Thanks guys. Maybe I can get to that this weekend.
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post #1095 of 1186 Old 07-03-2014, 08:21 AM
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Good progress! Now you can work in comfort... : )
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post #1096 of 1186 Old 07-03-2014, 11:34 AM
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I'm still trying to figure out your return duct layout. How does the total cross-sectional area change? Is your air handler under the stairs? Is that where the grill is? And then where does the 7" return run to again?

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post #1097 of 1186 Old 07-03-2014, 12:09 PM - Thread Starter
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JPA, I'll describe what I can, but posting from my phone, I may not have the images that might be needed.

The air handler is under the stairs built on a plywood box, about 15"-18" tall. Of course the box is the return or intake chamber - air is ejected through the six or seven flex ducts out the top (totally normal as far as I know). One side of the return box is very close to the wall of the lobby area, and there is a large return grill - maybe 1 foot square, maybe a little more. One other face of the return box has a 7" flex duct in it, coming through the face of the stairs - a small return grill is positioned in the riser of the fifth or sixth step. That's it for returns in the entire basement.

Before, as the system was designed, the theater and lobby areas were a single space, enclosed by doors I have since removed. This area was served by the single large intake grill. That area was approximately 35'x12'x9'. The 7" duct was the return for the remainder of the basement: the stairwell, the other room, and the bathroom. The "other room" in this scenario is approximately 19'x12'x9'. The bathroom is about 6'x10'x8' and the stairwell is probably half of 4'x9'x12'.

By adding the wall for the theater and removing the door that separates the stairwell from the lobby, I still have two areas, but of different volume and heat load obviously. The theater is 12'x9'x22' and has an 8" flex duct I place for the return. That flex duct will transition to filling a space in the staggered stud end wall before opening through the soffit at the rear of the room. The wall space will be approximately 11"x5" and 7-8' tall, running from under the outside riser to the theater soffit.

That leaves the remaining basement area with two possibilities for how to handle the return air. That remaining area includes the lobby, the "other room," the bathroom, and the stairwell. For that total now combined area, I have the large 1' square return and the option to keep the 7" flex or discard it.

Hopefully you can make sense of that and help me crunch the numbers.
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post #1098 of 1186 Old 07-03-2014, 02:20 PM
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My gut reaction to this is keep it simple. If I understand what you've got, the theater has an 8" return that will tie into the HVAC return box. The rest of the basement now has a 12x12 return in the lobby and a 7" flex in the stairwell. I think I would probably leave those just as they are unless you find something not working properly. I see three things that might happen:
  • It all works just fine. We can hope!
  • If for some reason the bathroom side of the basement doesn't seem to be getting enough air, you may need to relocate the 7" return to the wall facing into that space and/or close off part of the 12x12 return. I can't see how that would happen, but fluid flow does some surprising things.
  • If you don't have enough flow from the theater, you may decide to remove the 7" return to get a little extra flow from the other returns. Although I would probably start by blocking it off to see it makes any difference. Again, another possibility might be to reduce the size of the 12x12 return depending on how things are balanced.

I'm sure there other possibilities, but having been down the HVAC path before, I really think you're best off with the simplest solutions. In this case, I think I would connect my 8" return from the theater and see what happens. If you need to make changes after that, then we can put our heads together and see what options we have.

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post #1099 of 1186 Old 07-03-2014, 02:49 PM - Thread Starter
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That's the perfect response!

Every time I get into an esoteric field of science or engineering I find myself overwhelmed with data and possibilities. Having never been trained as an engineer, I always forget to step back and consider the system intent and limitations. I tend to try to work from an infinite list of possibilities instead of working from the much shorter list of practical options. Kudos.
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post #1100 of 1186 Old 07-03-2014, 03:01 PM
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Quote:
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That's the perfect response!
……..
Well, if it's any consolation, I had to learn this lesson the hard way. If you need proof just search my thread for HVAC, duct, or fan

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post #1101 of 1186 Old 07-04-2014, 05:42 PM - Thread Starter
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I need to talk through something else here - JPA's assistance may be required... The air handler is rated 1240 CFM, 30,000 BTU/hr


The heat pump has similar specs; it's 2-ton instead of the 2.5-ton of the air handler. 23,000 BTU/hr, and if I'm reading this table correctly, should be matched to an AHU at 860 CFM.


My first reaction there is that it seems the AHU I have should somehow be limited to low fan. (960 CFM from the AHU to match the 860 CFM recommended for the heat pump) I spoke with the HVAC repair guy the other day, who said that if the blower in my AHU was to be run at multiple speeds that there would be a provision for that on the control board, but there isn't - so he says. Can anyone speak to that?

The real reason for this post is I'm trying to figure out how large the supply registers need to be. They'll come through the face (or theoretically the bottom if better) or the soffits - one on each side near the screen. The maximum height is about 6 inches, and the maximum length is about 36 inches.

The theater has 2x 6" flex duct supplies. JPA's field sizing chart estimates each 6" round duct can supply 75 CFM. My air handler has 6x 6" flex ducts feeding from it, 2 to the theater and 4 elsewhere. If they were all the same length and shape, they would all move the same volume of air. Of course, they're not, so how do I go about estimating the volume through the theater ducts? Short of taking the approach that I'll have to tweak the register size, which I can make peace with ultimately - what's the data I need to figure this? If I had the volume through each duct, I could figure the face velocity through a given register - right? But is there another way? Maybe I should just assume 75 CFM in each duct, and shoot for 250 fpm based on that.

I know that most of the registers in the basement are unacceptably loud, and whatever standard size is (6x10?). It seems that the length of the ducts to the theater, which are the longest aside from the duct to the bathroom, which is very quiet and the same register as the others, would keep the registers quiet in the theater, but obviously I'd like to be sure. I can close off other registers to improve flow into the theater if I need to, so if volume is down in the long theater ducts, I can improve that after the fact.

Any thoughts?
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post #1102 of 1186 Old 07-04-2014, 09:02 PM
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4x24 for each supply. Would recommend a bar diffuser or linear slot diffuser. Either will work. DE recommends bar diffusers as they are slightly less turbulent.
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post #1103 of 1186 Old 07-04-2014, 09:06 PM - Thread Starter
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I have a hunch that's a number I can trust, but I have to ask anyway: did you calculate something for that, or do you just know somehow?
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post #1104 of 1186 Old 07-04-2014, 09:23 PM
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It's been calculated many times before and this is the minimum diffuser size to hit your FPM target IF you were truly pushing 75 CFM, but chances are you won't. My system is set to "high" fan for cooling and "low" fan for heating. In the high setting my system (2 ton, just like yours) puts out 860 CFM. The theater supplies are the first and third takeoffs from the main supply trunk line, which is a 14" round rigid duct. My anemometer measures the ducts at 65 and 63 CFM respectively.

As a footnote, my return duct has two rigid 90s and is connected directly to a rigid plenum box that the AHU sits on. The duct is 10" flex and goes to an oversized 14x14 return with the 1" panel filter (CFM dictates only a 12x12 return is needed, FYI). The panel filter can cause turbulence, so I have plans for a separate in-line plenum box that can be located close to the AHU that will handle the 1" panel filter and have an adjustable baffle to balance the return CFM with the supply.
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post #1105 of 1186 Old 07-05-2014, 07:38 AM
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Yup, sounds like your hunch was correct... : )
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post #1106 of 1186 Old 07-05-2014, 07:40 AM
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Just curious how you calculated 35.6% more procrastination ?
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post #1107 of 1186 Old 07-05-2014, 08:49 AM
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I've always felt that chart was making some significant assumptions. That said, I think you can size your return grills based on 75 cfm and be good. As TMcG pointed out, you are likely moving much less air due to the length of the run and the bends.

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Just curious how you calculated 35.6% more procrastination ?
Step one is to put it off till later.
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post #1108 of 1186 Old 07-05-2014, 09:48 AM - Thread Starter
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Quote:
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4x24 for each supply.
With 2 supplies and 1 return, the return should be approximately equal to the total area of the supplies, right? Or is there some adjustment to be made since I'm combining the two into one? (I wouldn't think so, just checking.) So I'm expecting to need somewhere around 200 square inches for return.

Shopping at HVACQuick.com, I'm looking at (2) Dayus DABL - Bar Linear Grill for an opening of 24" by 4" or do I need to go larger to get that much actual grill area? (pn in my basket is DABL-00-A-24x4-Brown-STD)
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post #1109 of 1186 Old 07-05-2014, 06:54 PM - Thread Starter
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With 2 supplies and 1 return, the return should be approximately equal to the total area of the supplies, right?
I think I've decided there is a better way to think about this. The 6" flex is designed for 75 CFM, but we upsize it at the grille to reduce face velocity and noise. Since a 4x24 rigid duct is designed for 330 CFM, I'll double that instead and find the rectangular duct size that's good for 660 CFM and use that for my intake grill. I think 8x18 looks good.

Too big?
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post #1110 of 1186 Old 07-05-2014, 08:04 PM
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Quote:
Originally Posted by HopefulFred View Post
I think I've decided there is a better way to think about this. The 6" flex is designed for 75 CFM, but we upsize it at the grille to reduce face velocity and noise. Since a 4x24 rigid duct is designed for 330 CFM, I'll double that instead and find the rectangular duct size that's good for 660 CFM and use that for my intake grill. I think 8x18 looks good.

Too big?
It's been a while since I sat down with our HVAC guy........I do know I have two 8" flex duct supplies with grills 12" X 24".

Returns were handled different for some reason but two 9" return flex duct with each grill being 85 square inches. I double check and had HVAC company guarantee 250 fpm ......

In 4300 cf room dead silent and is very well supplied with fresh air.

Based on your information provided, doesn't seem too large.....
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