John Sayers’ Recording Studio Design ForumAn archive of johnlsayers.com, 2003–2022

Help with a basic Ventilation Setup

Started by Matt Whritenour on 17 April 2008. 16 replies. In the Library under HVAC and ventilation.

Originally posted at johnlsayers.com, topic 10488.

Matt Whritenour
Hi, I'm going to be building a drum booth in my basement and I'm trying to keep the cost down as much as possible. So far I've made the window and this weekend I'm going to get the door jam all setup so that i know the exact sizes i need so that I can begin framing. This Link: http://www.johnlsayers.com/phpBB2/viewt ... highlight= has the shape I am going to be constructing except i changed a few things like instead of the interior walls being 10' the exterior walls will be for easier construction, ect. Since it's just a drum booth and in my basement I don't want to and cannot spend the money on a type of hvac setup, I just want to be able to force air from the basement (which the basement is finished) into the booth and I probably also need a type of exhaust in the booth. I kind of stuck with this trying to figure out the best/cheapest way to do it while not letting too much noise in from a fan and not letting too much noise out. I've had Ideas like using 2-3" pvc pipe to make a duct starting from outside the booth near the ground where the air is colder then the pipe would go up the wall and enter the booth from the top of the wall, Thinking I can rig a small fan like a 120mm computer fan to bring air in and possibly have one on the outtake sucking air out, but I'm not sure if that would move enough air, or how loud the fans would be and how much noise would escape through the pipe. Hopefully my post makes sense and someone can help me with a cheap solution or possibly chime in if my idea would basically work. Thanks, -matt
rod gervais
while you're a it - you better figure out a way to heat that air in the dead of winter - and a way to dehumidify the room in the warm and hot months of the year. Rod
Eric_Desart
BradJacob wrote:
Damn Glen, you sure are good with those drawings!
:mrgreen: Yes he is ...., very much so ...... And I'm jealous, still hoping the holy spirit will help me doing the same. :( But I'm scared I'll have to do and learn it myself.
Ro
Gulffo sure has got too many free time.... and I'm glad he does :) Darn that's some good drawingskills.
Matt Whritenour
around how much will it cost for a system like this? and are there 2 fans? one for intake and one for outtake? I was hoping i wouldn't need an exhaust fan that the air would make its way out the exhaust pipe anyway. All the fans i find are more than i'd like to spend but i'd be able to stretch it a little bit but 2 fans is just gonna add on a lot. thanks!
gullfo
thanks for the compliments... Eric - you can always tap me to help you out with things you need drawn up :-) you need the 2 fans to keep the flow... i've seen some Panasonic exhaust fans with 0.3 sone levels w/ 75-100cfm. and i believe they're reversible in terms of flow... http://www.energyfederation.org/consume ... 30_85_1358
Corbin
Gulfo I have two questions... 1) How would you reverse the air flow for the units? When you wire up the unit would you just flip hot & cold? 2) Would 1 unit on the exhaust that removes air be just as effective as 2 units that push and pull? In other words would a single exhaust unit effectivley create a cyphon for the air in the room and eliminate the noise from a second unit? Thanks! And very nice drawings.... mark
rod gervais
Corbin wrote:
Would 1 unit on the exhaust that removes air be just as effective as 2 units that push and pull? In other words would a single exhaust unit effectivley create a cyphon for the air in the room and eliminate the noise from a second unit?
Actually - your best installation would be to push air into the space - pressurize the space - and then balance using a barometric damper to control the required flow - leaving the room slightly pressurized. Negative pressure rooms invite outside sounds in - positive pressure helps keep them out. Remembering (of course) that where air can go - so goes sound. You don't need a lot of static pressure - but can set it how you wish - the key is picking up the fan that provides the flow you want at the static pressure you desire. So if you want 125 cfm of fresh air - and you pick one capable of producing that with 1" of static pressure - then you can pressureize the room to an inch of static pressure and get all of your flow. You do not (at these volumns) require 2 fans - and I can't see the benefit in being able to reverse them - what do you gain? To change from heat to no heat is simple - you install a heating element - hook it up to a thermostat that installs directly inside the duct (downline from the heating element) and then wire it into a switch in the control room to turn the fan on and off. If your comfort level for air blowing on you is 70 degrees - then simply set the t-stat to roughly 72 degrees - (they swing about a 6 degree variance - 3 below setting to 3 above setting) That will average slightly higher than the 70 you want (72 to be exact) nut will only be about a degree below where you like it in the worse case. When it's on and the temps are above 72 degrees outside it just never calls to warm the air - all you do is hit the switch when you walk in the room (or if you want - tie the power into your light switch - when the lights are3 on the fan is on). that is about as simple as it gets. As far as quiet goes - that is a function of the noise produced by the fan itself (either traveling through the duct or through the structure) - plus the noise produced by the movement of the air through the duct. It is a simple matter to take the duct size and increse it to produce exactly the same volume of air at a lower velocity - so air movement should never be a problem. The motor noise is also easy to handle - through the use of vibration isolating hangers to stop the possibility of physical transfer through the structure (reccomended even if you are hanging it from the outside room) and then the use lined duct and finally introducing the air into the room via an isolation box. Reality is that for what you are talking aabout here now - this is no big deal - we do this sucessfully with huge systems in commercial facilities all the time - move a LOT of air - and never have a problem with any sound at all. We are moving 1350 cfm of air directly above the desk in a studio I designed in the Phillapeans - the owner of the studio can't hear it (or anything else)- can't feel the flow (the cool air just sort of drops slowly into the room) - and a microphone directly below a supply register dumping 450 cfm can't pick up any disturbance. How difficult can it be with 125 cfm of air? Sincerely, Rod
clunk
Rod I am wondering if this contradicts advice you gave in another post in which you say
rod gervais wrote:
Some fans push better than they pull - for example - those Broan Fans I provided info on earlier- - the don't want to see duct before the inlet........... I usually want my fans to be connected to the exhaust side of the equation - that is then taking the fan noise and sending it away from the critical space......... which is what I do with stand alone specialty fans.........
rod gervais
clunk wrote:
Rod I am wondering if this contradicts advice you gave in another post in which you say
rod gervais wrote:
Some fans push better than they pull - for example - those Broan Fans I provided info on earlier- - the don't want to see duct before the inlet........... I usually want my fans to be connected to the exhaust side of the equation - that is then taking the fan noise and sending it away from the critical space......... which is what I do with stand alone specialty fans.........
I don't believe so - I think I was speaking of a whole system there (I would like to see a link to your quote) - in a whole system I always tie my fresh air into the exhaust side of the system - which is the return air side - and then I install a relief with barometric pressure control upstream from the inlet - this way you're still pressurizing the room. Also - there may be cases where someone has used undersized duct - and can't change it - at which point you don't have much choice but to choose more noise than the duct itself might produce (fan noise) - or just deal with the velocity issue - In those cases I would generally reccomend that they install an outlet fan instead of an inlet fan - give up on the pressurized room because of the cost in additional noise........ But, again - I have to read the post i made to determine the context......... but I don't believe I contradicted myself (I'm usually pretty carefull about that). So post the link please........ Rod
clunk
Hi Rod thank you for getting back so soon on this, here is the link http://www.johnlsayers.com/phpBB2/viewt ... ion+baffle The reason I ask is that I had been planning out a ventilation system for my own studio build and having read this post totally changed what I had been planning from an exhaust sytem to a push system, in my situation I plan to use a fan capable of pushing/pulling about 500 cubic meters per hour. From my reading of this post I had assumed that to develop a positive pressure in a room you had to push air into the space while pulling air from the room created a negative pressure. Could you please clarify this. I had posted a question about this earlier but the only advice I got was a post suggesting I was ignoring your advice which I was not. If you want to look at this it's here : http://www.johnlsayers.com/phpBB2/viewtopic.php?t=10681 I will be updating it this weekend with a drawing of the proposed system and I would appreciate your thought on this The rest of my studio build can be found here : http://www.johnlsayers.com/phpBB2/viewtopic.php?t=10177 Again thanks for getting back on this, all the best Clunk
rod gervais
Clunk - Just what I thought - this was a case of a severly reduced duct size (a 44% reduction of the minimum reccomended duct size by the fan maufacturer - and that size is smaller than you would want for a studio. So no - no contradiction. AS long as you are oversizing the duct so you move large volumes at low velocities - AND - the fan is remote from the room and not connected directly will all hard duct - then a puch into the room (with barometric relief) is the BEST way to go - If you have an air handler - then you want to tie this into the return air side of the system directly before the air handler - and then go downstream at least 10' to install your pressure relief to the outside world. Not all that tough......... If this is stand alone fresh air - then you are going to have to temper it somehow - to make it warm in the winter and probably less humid in the summer......... See if any of that makes sense......... Rod
studio_drums
I recommend spending your time and energy looking into a way to cool the room rather than heat it. In my experience practicing drums in smallish enclosed spaces, they heat up very quickly and do not require heating of any kind. Trust me- cooling and recirculating the air in the room is the most important part of your project! So please do yourself a favor and do not rule the cooling part out of it...fresh air will certainly help to a point...is there a way for you to cool the room outside of the room so that you're recirculating cooler air?
xSpace
Kevin Myers, a columnist for the Irish Times wrote "Summer in this country is a fraud . . ." They are familiar with cold days.