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Portable A/C unit is noisy (the kind on casters)

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June 9, 2005 5:12:08 PM

Archived from groups: rec.audio.pro (More info?)

This may be slightly off topic, but I just purchased a Royal Sovereign 9000
BTU Portable Air Conditioner. This is
the kind that doesn't mount in a window, and is on casters. (I can't use a
window unit where I live) The unit works, but, since I value my hearing, I'm
disappointed that it is
rather noisy. I have a Radio Shack Sound Level Meter and at the "A
Weighting" setting (the less sensitive setting) I"m getting a measurement of
62db at around 3 feet from the unit. Believe it or not, the fan itself
makes most of the noise (at the lower speed) and the compressor only makes a
1 or 2 db difference. There is no published spec for noise on the unit I
bought.

I notice that there are other units that are advertised as having lower
sound levels, such as the "Edge Star 9000btu" which is said to have a noise
level of less than 54db, and the "Delonghi PAC-03" which is said to have a
noise level of 50db or less.

Has anyone here had experience with Portable A/C units that are on casters
and don't mount in windows?

Is it likely true that the above two units are actually 8 to 12 db quieter
than mine? I'd hate to go through the trouble of returning the Royal
Soverign only to find that the published specs on the other two units are
false. Should I return the Royal Sovereign and try one of the other units?
(Keep in mind that this it will be a major pain in the neck repackaging this
thing and returning it to Sears, and the other units are only available to
me via UPS or Fedex shipping.)

Thanks,

J.
Anonymous
June 9, 2005 5:12:09 PM

Archived from groups: rec.audio.pro (More info?)

In article <IeXpe.10538$nk4.1387@trndny01> jaynews@verizon.net writes:

> I have a Radio Shack Sound Level Meter and at the "A
> Weighting" setting (the less sensitive setting) I"m getting a measurement of
> 62db at around 3 feet from the unit.

Check it with C weighting. That lets more low frequencies at the
meter. You'll probalby get a higher reading. A weighting is
appropriate for setting limits for hearing damage, but C weighting
will give you a better idea of what's more annoying.

> I notice that there are other units that are advertised as having lower
> sound levels, such as the "Edge Star 9000btu" which is said to have a noise
> level of less than 54db, and the "Delonghi PAC-03" which is said to have a
> noise level of 50db or less.

> Is it likely true that the above two units are actually 8 to 12 db quieter
> than mine? I'd hate to go through the trouble of returning the Royal
> Soverign only to find that the published specs on the other two units are
> false. Should I return the Royal Sovereign and try one of the other units?

I would, but then I return most of the stuff that I buy these days.
You simply can't tell unless you try, you can't always trust the
reviews, and the manufacturers want to make their products look as
good on paper as they can get away with.

Seeing as how you'll have to mail order the alternatives, I'd go ahead
and order one while you still have the Sears unit, and compare them.
Then return the noisiest one. If that's still not quiet enough for
you, order the other one and compare it with the one that's quieter
than the Sears one.

The question is, are you bothered enough by the noise so that it's
worth the trouble, the trip back to Sears, and the shipping costs (and
possible restocking fee) of the mail-order units? 62 dBA isn't going
to damage your hearing, but I sure wouldn't want to record with that
racket going on in the control room or studio. I turn off the air
conditioning (and heat) when I record in my house. Recording season
isn't very long around here since we hardly have any Spring and Fall
is sporadic and can't be depended on when scheduling sessions.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
June 9, 2005 8:06:01 PM

Archived from groups: rec.audio.pro (More info?)

I test drove a Delonghi/Pinguin, and although the motor was pretty
quiet
the rushing noise of the air coming out of it was very audible, and
there isn't much
you can do about it. Big installed systems for studios use large ducts
and plenums so that they can move a lot of air slowly, which makes it
quieter.
Small systems use smaller ducts and faster fans, all of which makes for
more noise. I've been trying to figure this problem out for myself
for many years, and have so far concluded that some kind of (expensive)
installed system is the only way to have a space be quiet and cool.

Philip Perkins
June 9, 2005 9:48:46 PM

Archived from groups: rec.audio.pro (More info?)

Actually I measured again and it's around 60 db (A-weighted at 3 feet).

I wonder what the standard methodology is for measuring room A/C noise. Do
they use an A-weighted reading in "anechoic champer" at a distance of 3
feet? If so, then perhaps my unit would spec out close enough to the other
units in an "anechoic champer" that it would not be worth all that hassle?
<Grin>

J.
June 9, 2005 9:51:46 PM

Archived from groups: rec.audio.pro (More info?)

By the way, I agree that I can't record anything with a mic with the A/C on
but I can still record guitar direct and do editing, especially with
headphones.

J.
Anonymous
June 9, 2005 9:56:29 PM

Archived from groups: rec.audio.pro (More info?)

did they do that consistently into the 1980's, or was that just one of
their "experiments" that they did for a tour or two?
June 9, 2005 11:13:26 PM

Archived from groups: rec.audio.pro (More info?)

On Thu, 09 Jun 2005 16:06:01 -0700, spamiser wrote:

> I test drove a Delonghi/Pinguin, and although the motor was pretty
> quiet
> the rushing noise of the air coming out of it was very audible, and
> there isn't much
> you can do about it. Big installed systems for studios use large ducts
> and plenums so that they can move a lot of air slowly, which makes it
> quieter.
> Small systems use smaller ducts and faster fans, all of which makes for
> more noise. I've been trying to figure this problem out for myself
> for many years, and have so far concluded that some kind of (expensive)
> installed system is the only way to have a space be quiet and cool.
>
> Philip Perkins

Interesting!
Maybe putting the unit in another room and rube goldberging some kind of
duct work to send the air into the studio?

--
Dana Larsen
(Leave one 6 and remove everything after to reply)
Anonymous
June 10, 2005 12:30:44 AM

Archived from groups: rec.audio.pro (More info?)

On Thu, 09 Jun 2005 13:12:08 GMT, "jay" <jaynews@verizon.net> wrote:

>Believe it or not, the fan itself
>makes most of the noise (at the lower speed) and the compressor only makes a
>1 or 2 db difference. There is no published spec for noise on the unit I
>bought.
Is this noise from the motor or the Air being chopped by the
blade-grill interaction?
What type of fan blades (room and condensor sides) are used?

, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
Anonymous
June 10, 2005 1:37:54 AM

Archived from groups: rec.audio.pro (More info?)

In article <1118364989.588478.122400@g44g2000cwa.googlegroups.com>,
<genericaudioperson@hotmail.com> wrote:
>did they do that consistently into the 1980's, or was that just one of
>their "experiments" that they did for a tour or two?

The Wall of Sound only lasted for a few years. It had the dual problems
of being very difficult to transport and sounding like the voices were
coming through a telephone due to the comb filtering from the dual omni
mikes.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
June 10, 2005 2:05:06 AM

Archived from groups: rec.audio.pro (More info?)

<<Is this noise from the motor or the Air being chopped by the
blade-grill interaction?
What type of fan blades (room and condensor sides) are used?>>

I don't know what type of fan is on the condensor side. The condensor is in
the room, since it's a portable unit on casters. The fan that blows the air
into the room is some type of rotary spindle. Imagine a spindle for a roll
of toilet paper with fins attached. I can remove the grill, but it doesn't
lower the DB.

J.
June 10, 2005 2:05:07 AM

Archived from groups: rec.audio.pro (More info?)

On Thu, 09 Jun 2005 22:05:06 +0000, jay wrote:

> <<Is this noise from the motor or the Air being chopped by the
> blade-grill interaction?
> What type of fan blades (room and condensor sides) are used?>>
>
> I don't know what type of fan is on the condensor side. The condensor is in
> the room, since it's a portable unit on casters. The fan that blows the air
> into the room is some type of rotary spindle. Imagine a spindle for a roll
> of toilet paper with fins attached. I can remove the grill, but it doesn't
> lower the DB.
>
> J.

Squirrel cage!!!
Try putting foam under the castors. You may be transferring vibration to
the floor.
Other than that, I think you might be sol :( 
--
Dana Larsen
(Leave one 6 and remove everything after to reply)
Anonymous
June 10, 2005 2:05:07 AM

Archived from groups: rec.audio.pro (More info?)

In article <m23qe.14227$MX2.12312@trndny03>, jay <jaynews@verizon.net> wrote:
>
>I don't know what type of fan is on the condensor side. The condensor is in
>the room, since it's a portable unit on casters. The fan that blows the air
>into the room is some type of rotary spindle. Imagine a spindle for a roll
>of toilet paper with fins attached. I can remove the grill, but it doesn't
>lower the DB.

This is called a "squirrel-cage blower" and it's one of the more noisy
kinds of fan, but also one of the more compact ones. Systems designed for
low noise tend to have very large fans that move a lot of air at slow
speed, instead of smaller fans that move a small amount of air very fast.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
June 10, 2005 3:53:56 AM

Archived from groups: rec.audio.pro (More info?)

Is there a such thing as an electronic device that has a microphone and will
generate sound waves out of phase from what the mic picks up and then plays
them through a speaker to cancel the noise?

I know there are "noise canceling headphones" I'm just wondering if there
are "noise canceling speakers" that exist only for the purpose of canceling
unwanted room noise like the noise from my A/C.

J.
June 10, 2005 3:53:57 AM

Archived from groups: rec.audio.pro (More info?)

On Thu, 09 Jun 2005 23:53:56 GMT, "jay" <jaynews@verizon.net> wrote:

>Is there a such thing as an electronic device that has a microphone and will
>generate sound waves out of phase from what the mic picks up and then plays
>them through a speaker to cancel the noise?

The Grateful Dead used noise canceling microphones so they could set
up in front of the mains and hear exactly what the audience heard.
they were 2 capsules close together, one out of phase and they sang
very close into only one capsule. Rent the "Grateful Dead Movie" to
see what they looked like.

Julian
Anonymous
June 10, 2005 3:53:57 AM

Archived from groups: rec.audio.pro (More info?)

In article <oE4qe.8782$zT2.5163@trndny04>, jay <jaynews@verizon.net> wrote:
>Is there a such thing as an electronic device that has a microphone and will
>generate sound waves out of phase from what the mic picks up and then plays
>them through a speaker to cancel the noise?
>
>I know there are "noise canceling headphones" I'm just wondering if there
>are "noise canceling speakers" that exist only for the purpose of canceling
>unwanted room noise like the noise from my A/C.

This sort of thing can be made to work in very specific controlled
conditions, and it basically has to be engineered for the particular
application. But I have seen active noise cancellation systems installed
into ducts in order to reduce HVAC system noise. It's not practical
for what you want to do, though, and it's definitely not cheap.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
June 10, 2005 3:53:58 AM

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey wrote:
> In article <oE4qe.8782$zT2.5163@trndny04>, jay <jaynews@verizon.net> wrote:
>
>> Is there a such thing as an electronic device that has a microphone and will
>> generate sound waves out of phase from what the mic picks up and then plays
>> them through a speaker to cancel the noise?
>>
>> I know there are "noise canceling headphones" I'm just wondering if there
>> are "noise canceling speakers" that exist only for the purpose of canceling
>> unwanted room noise like the noise from my A/C.
>
>
> This sort of thing can be made to work in very specific controlled
> conditions, and it basically has to be engineered for the particular
> application. But I have seen active noise cancellation systems installed
> into ducts in order to reduce HVAC system noise. It's not practical
> for what you want to do, though, and it's definitely not cheap.

Convection cooling is your friend. Not cheap either, but dead quiet.
Anonymous
June 10, 2005 12:02:42 PM

Archived from groups: rec.audio.pro (More info?)

In article <m23qe.14227$MX2.12312@trndny03> jaynews@verizon.net writes:

> The fan that blows the air
> into the room is some type of rotary spindle. Imagine a spindle for a roll
> of toilet paper with fins attached.

That's called a squirrel cage blower, though it's more typical of
hamster cages. But then people didn't put hamsters in cages with
exercise wheels back when they invented the squirrel cage blower.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
June 10, 2005 7:50:01 PM

Archived from groups: rec.audio.pro (More info?)

genericaudioperson@hotmail.com wrote:
> did they do that consistently into the 1980's, or was that just one of
> their "experiments" that they did for a tour or two?

It was pretty short term (37 shows over 7 months) due to the enormous cost -
it weighed 72 tons, took 5 trucks to haul, and required 2-3 seperate crews
to set up.

--
Aaron
June 11, 2005 4:05:28 AM

Archived from groups: rec.audio.pro (More info?)

On 10 Jun 2005 15:50:01 GMT, <aborgman@redshark.goodshow.net> wrote:

>genericaudioperson@hotmail.com wrote:
>> did they do that consistently into the 1980's, or was that just one of
>> their "experiments" that they did for a tour or two?
>
>It was pretty short term (37 shows over 7 months) due to the enormous cost -
>it weighed 72 tons, took 5 trucks to haul, and required 2-3 seperate crews
>to set up.

Sounds like a typical rock show load in to me!

Julian
!