HVAC info?

[archive]

From: "Dave Martin" <dave.martin@x?????xxxx.xxxx
Date: Thu Nov 11, 1999 5:59 pm
Subject: HVAC info?

This question is probably only tangentially related to acoustics, but since
it has everything to do with control rooms, I wanted to post it here.

Is there a site or a book that gives useful information about installing
ductwork and figuring out the size of an air conditioning unit for a room?

I notice that most hardware and DIY stores have books on plumbing,
electrical, carpentry, even brick laying, but I haven't run across anything
specifically related to heating and air conditioning.

I would appreciate any pointers.

Thanks,

Dave Martin
DMA, Inc.
Nashville, Tennessee
dave.martin@n...

[archive]

From: "CactusFire (A.S.)" <cactusfire@x??????xxxxx.xxxx
Date: Thu Nov 11, 1999 7:49 pm
Subject: Re: HVAC info?

Dave, the best way to size your machine is to call the manufacturer and give
them your total cubic feet. They will then recommend a unit, and you should
then buy the next higher size, so that you can run it at it's lowest settings,
plus have a little room for expansion.

As far as installing ductwork, I like the flex ducting, which is very easy to
install, and surrounded by insullation. I think it will give you far less
headaches than galvanized ducting. As far as sizing the ducting, figure out
what you need (you can also get this from the manufacturer), then add 20%. For
instance, if your layout and volume call for 10" ducts, get 12" ones. This
will reduce the air velocity while keeping the circulation rate that you need.

As far as books, if you find one, let me know. Where I live, it's illegal for
a homeowner to do any HVAC work. It must all be done by a licensed mechanical
contractor. If this is a widespread policy, then it's no wonder there are not
any books on the matter.

Also, as it happens, I am currently finishing up an article on do-it-yourself
HVAC for Dan's site. It's not particuarly authoritative, instead, it's more of
a "this is how I did it" kind of thing. It might be helpful. Good luck,

Andy

[archive]

From: "Cliff Kaminsky" <cliff@x???xx.xxxx
Date: Thu Nov 11, 1999 7:50 pm
Subject: Re: HVAC info?

Look up ASHRAE (American Society of Heating, Refrigeration and
Air-conditioning Engineers) on the web. They should have some references.

Cliff Kaminsky
Vibro-Acoustic Sciences, Inc.

[archive]

From: Dan Nelson <dprimary@x??????xxxxx.xxxx
Date: Fri Nov 12, 1999 1:17 am
Subject: Re: HVAC info?

Try McGraw Hill at http://www.bookstore.mcgraw-hill.com/ and search for HVAC
they have about 20 books on the subject

Dan Nelson
www.studiotips.com

[archive]

From: "Dave Martin" <dave.martin@x?????xxxx.xxxx
Date: Fri Nov 12, 1999 4:47 am
Subject: Re: HVAC info?

>
>Dave, the best way to size your machine is to call the manufacturer and
give
>them your total cubic feet. They will then recommend a unit, and you should
>then buy the next higher size, so that you can run it at it's lowest
settings,
>plus have a little room for expansion.

Well, that's the general idea, but with a large format console and 120-140
rack spaces of equipment (much of it either tube or Class A), the heat
generated by equipment is way out of line with a typical home or office. The
last room I used for this in a basement that was approximately 15x25x7.5
feet; last winter, I never turned on a heater for that room, and during this
summer, if I turned the AC off for 45 minutes, the ambient temperature in
the room would rise to more than 85 degrees.
>
>As far as installing ductwork, I like the flex ducting, which is very easy
to
>install, and surrounded by insullation. I think it will give you far less
>headaches than galvanized ducting. As far as sizing the ducting, figure out
>what you need (you can also get this from the manufacturer), then add 20%.
For
>instance, if your layout and volume call for 10" ducts, get 12" ones. This
>will reduce the air velocity while keeping the circulation rate that you
need.

Flex duct looks sensible to me, but I was told that you can't split a run
(for instance, to take the main air duct and split it to two sides of the
room) from a flex duct; it has to run off of a galvanized duct. And it looks
as though my local Home Depot sells lined flexible duct in 25 foot sections;
form the unit that I intend to use temporarily, the distance is about 30
feet. I'm not even sure how you'd connect two of them together...

I'm actually wanting to do a couple of different things; the most pressing
is to run ducts into the garage that I'm currently using as a studio, and
the other is to start gathering information for a ground up studio that I'm
planning.
>
>As far as books, if you find one, let me know. Where I live, it's illegal
for
>a homeowner to do any HVAC work. It must all be done by a licensed
mechanical
>contractor. If this is a widespread policy, then it's no wonder there are
not
>any books on the matter.

Cliff Kaminsky, from Vibro-Acoustic Sciences, Inc. suggested

http://xp10.ashrae.org/bookstore/bookstore.html

which is definitely the site for books on this subject; now I get the joy of
narrowing them down...
>
>Also, as it happens, I am currently finishing up an article on
do-it-yourself
>HVAC for Dan's site. It's not particuarly authoritative, instead, it's more
of
>a "this is how I did it" kind of thing. It might be helpful. Good luck,
>
>Andy
>
I'll look forward to reading it, and thanks to all for the information.

Dave Martin
DMA, Inc.
Nashville, Tennessee
dave.martin@n...

[archive]

From: Dan Nelson <dprimary@x??????xxxxx.xxxx
Date: Fri Nov 12, 1999 7:05 am
Subject: Re: HVAC info?

Dave Martin wrote:

>
>
> Flex duct looks sensible to me, but I was told that you can't split a run
> (for instance, to take the main air duct and split it to two sides of the
> room) from a flex duct; it has to run off of a galvanized duct. And it looks
> as though my local Home Depot sells lined flexible duct in 25 foot sections;
> form the unit that I intend to use temporarily, the distance is about 30
> feet. I'm not even sure how you'd connect two of them together...

They should have Y's and T's for flex at Home Depot it is galvanized I believe
they are the same for both galvanized duct and flex duct. You seal the inner
liner of the flex to the Y with foil tape and then they sell big tie wraps that
go around the outer liner to hold it on the Y.
How big is the present a/c? and the present room?

Dan Nelson

[archive]

From: "Dave Martin" <dave.martin@x?????xxxx.xxxx
Date: Fri Nov 12, 1999 3:45 pm
Subject: Re: HVAC info?


I'll check for Y and T's for Flex today - the present room is 22x25x9 (more
or less). the present unit (which is actually built to cool the upstairs, is
a 3 ton. I can run the main air send and return to the room through the
attic, though I can't access the entire room from above - I'll either have
to break it out once it gets to this room, or I'll just have to put the air
return as far from the send as I can get it and point the send so it shoots
across the room... Or I can let the ductwork jut hand from ceiling and let
everyone get over the fact that they can see it...

I realize that this is an inelegant solution, but as I said, this is a
temporary work space.

Dave Martin
DMA, Inc.
Nashville, Tennessee
dave.martin@n...

[archive]

From: "CactusFire (A.S.)" <cactusfire@x??????xxxxx.xxxx
Date: Fri Nov 12, 1999 6:23 pm
Subject: Re: HVAC info?

Dave Martin wrote:

> Flex duct looks sensible to me, but I was told that you can't split a run
> (for instance, to take the main air duct and split it to two sides of the
> room) from a flex duct; it has to run off of a galvanized duct. And it looks
> as though my local Home Depot sells lined flexible duct in 25 foot sections;
> form the unit that I intend to use temporarily, the distance is about 30
> feet. I'm not even sure how you'd connect two of them together...
>

This stuff is really easy to work with. You can get these galvanized joiners
that rotate in sections and which allow you to connect flexducting end to end
or at any angle. Like Dan said, you just peel back the outer cover and
insulation, then pull the inner sleeve over the connector, tape it, then pull
the insulation and cover back over and wrap these plastic cinchers (sp?) around
the whole thing. The connectors have ribs on them so that the cinchers easily
hold the ducting over the connector. Fortunately, all the materials are pretty
inexpensive.

In my tracking room, I have two 12" feeds which "T" up in the ceiling and give
me four ducts (also 12") blowing into the room. The air velocity is low at the
vents, but the volume of circulating air is quite high. It's kind of a thrill
every time I'm under a vent when the AC kicks in and I feel a nice wash of cool
air, but hear nothing.

>
> I'm actually wanting to do a couple of different things; the most pressing
> is to run ducts into the garage that I'm currently using as a studio, and
> the other is to start gathering information for a ground up studio that I'm
> planning.
>

I would love it if you would keep the list posted on your plans. In fact, I
think it would be interesting to start a database of construction tales from
project studio owners/builders. There are so many variable is designing and
building a studio that you just can't figure out until you have tried it. After
having built a few myself, I really respect those companies that will design
the building and oversee the construction to acoustic specifications. There are
so many little details. Even having hired a contractor to build mine, I still
find that taking care of all the little-- but so important-- details is almost
a full time job. Trying to do this and keep the existing studio running full
time has me at the end of my rope more often than not.

Andy

[archive]

From: john/blackcabin <rockin@x?????xxxx.xxxx
Date: Sun Nov 14, 1999 4:06 pm
Subject: Re: HVAC info?

Dave Martin wrote:
>
> From: "Dave Martin" <dave.martin@n...>
>
> >
> >Dave, the best way to size your machine is to call the manufacturer and
> give
> >them your total cubic feet. They will then recommend a unit, and you should
> >then buy the next higher size, so that you can run it at it's lowest
> settings,
> >plus have a little room for expansion.
>
> Well, that's the general idea, but with a large format console and 120-140
> rack spaces of equipment (much of it either tube or Class A), the heat
> generated by equipment is way out of line with a typical home or office. The

Dave,

Being a "rural" based electrical customer, you may want to consider
installing a smaller dedicated heat-pump for your garage/room.
IMO, the overall gains in the efficiency of your
cooling/heating/power usage far outweigh the cost of the additional unit.
When pressed, CEMC will even retro a larger transformer for you.

Oh... if you do build a dedicated building, just move the unit.
And... I really like the idea (and aesthetic) of using "exposed duct
work" in your garage.

John
--
the little house that rocks
www.blackcabin.com
931-358-0114

"Soundmen are like high school teachers; they all start out fine but,
later in life, have had to deal with way too many morons and
dangerous types to have much good nature any more, or patience, or
belief that people are basically good."
- Tommy Womack from the "Cheese Chronicles" -