[simpits-tech] How do you deal with temperature inside the pit?

Craig Rochester simpits-tech@simpits.org
Mon, 25 Nov 2002 18:48:43 -0500


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Here's a rough sketch of the idea for a "widow" A/C connected to a pit:
http://pages.zdnet.com/johncraigrochester/sitebuildercontent/sitebuilderpict
ures/.pond/ac.jpg.

Craig R.

 -----Original Message-----
From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org]On Behalf Of Craig Rochester
Sent: Monday, November 25, 2002 5:45 PM
To: simpits-tech@simpits.org
Subject: RE: [simpits-tech] How do you deal with temperature inside the pit?


  Hi Albert,

  Sorry for the tardy response, but work's real busy right; major HVAC
project.  I'm working on a "fill room" cleanroom.  The room is 14' x 15' x
9' tall and has 7,500 CFM air flow.  The air is replaced in the room 4.5
times a minute.  The temperature is held to 65F +/- 1F and RH to 45%  +/-
5%.  The equipment could easily condition a couple of medium size houses.

  FWIW, here's some info on RH vs.. T:

  Here's a link for the "psychrometrics" of air:
http://www.ianr.unl.edu/pubs/generalag/g626.htm#air

  Relative humidity is a measure of the moisture absorbed by air.  Warm air
can hold a lot more water than cold air.  For a given temperature, the air
has a maximum about it can absorb.  The RH number in % is the amount water
in the air divided my the maximum amount it could hold at that
temperature(saturated).  So when you heat up some air with a certain RH, the
amount of water remains constant, but the RH goes down. Also, humidity
"moves" differently than heat.  Humidity will "migrate" from humid air to
less humid air as pressure is the driving force(vapor pressure).

  So why the RH sermon?  It makes a real difference for a person's comfort.
Our bodies cool by evaporative cooling(sweating).  As the air becomes more
humid, the sweat evaporates less efficiently to a point where we sweat
faster than it dies and we get "sweaty" = uncomfortable.  Also, as the sweat
evaporates and we breath out moist air, the RH in a small space like a
cockpit will increase to a point where the air is saturated and condensation
will form on the cooler surfaces(stuff will fog up).

  The problem with evaporative cooling is that the process adds moisture to
the air, and in a closed room, the humidity will rise to a point where the
cooler won't cool anymore(the fan will add heat).  With room air conditions
you gave, 90F/30%, if you cooled this to 70F with evaporation you'd have
about 85% RH.  That's sticky.

  With a standard A/C unit(vapor compression) air is cooled to the point
where the water condenses out(it drips out the bottom), and you get "free"
dehumidification,.  So not only do you cool the air, but you knock down the
humidity, both together provide a comfortable feel.  I like warm and dry
better than cool and damp.  My favorite conditions for low physical activity
is 70F with 45% RH(max 50%).  I might even drop that a bit when flying
Falcon4, as bogeys are always on my butt.

  A small "window" A/C, about 4,000 BTU(1500 kW), is about 18" x 20" x 14"
tall.  I've got two, both of which I got off the street(trash day) and
worked after cleaning the coils. I'll draw a diagram to illustrate what I
have in mind, if you're interested.

  Craig R.


   -----Original Message-----
  From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org]On Behalf Of Albert Yung
  Sent: Thursday, November 25, 1999 2:39 AM
  To: simpits-tech@simpits.org
  Subject: Re: [simpits-tech] How do you deal with temperature inside the
pit?


    Hi Craig,

    I invested in a half decent Hygrometer with in/out thermo reading. This
will allow me to give you some good reading of my room. Also in the
afternoon rush hour, I went to a electronic chain here just before they
closed today...only saw the evaporative cooler. Cool my brain off first
before I walk back out to the 84degree heat. With my newly purchase gadget,
I can tell you today's relative humidity is 33% with a chances of a late
shower...hehe. Today was the Hotest November night since 1988....in Sydney.

    Anyway, I agree with you. If the monitor are located inside the pit then
it will dramatically increase the heat factor. Sucking outdoor air into the
pit has been considered...but might not be possible to achieve. My room size
is 12ft x 9ft. Brick wall facing north east and north west. Window is about
2.5ft by 4 ft.facing the north west.

    Architectural wise, this room get good use of natural sunlight and also
get a good breeze from the door which directly face the window.

    Ok, here's the weather update...right now. its 31degree C or 87.6 F in
here...the back of 3 monitors is 99.7F  the room's relative humidity was
37%. 8% lower than it was when I first entered the room with window shut...

    Unfortunately, it will be very impossible to mount a window unit on a
stand...or anywhere in the room... There are a few floor standing
evaporative cooler which kinda feel cool. I might get one of them since it
only cost about 100USD. Try it out in my room and see how much they can cool
the room for normal purpose. However, I do question the reading I got here
36% RH will prehaps make the Evaporative cooler less effective.

    I found an old fan which I can use maybe to provide suction out of the
pit or blowing it into the pit. While other issues you mentioned I will get
to them in a direct email to you :)

    Thanks a tonne for every bit of your advise mate! I can not do without
them.

    Albert


      ----- Original Message -----
      From: Craig Rochester
      To: simpits-tech@simpits.org
      Sent: Monday, November 25, 2002 5:48 AM
      Subject: RE: [simpits-tech] How do you deal with temperature inside
the pit?


      Hi Albert,

      I think ventilation is important to consider in the design.  Not only
for your comfort, but for the reliability of the electronics.  E.g.., if a
monitor is in the pit, that's a lot of heat.  I live in Boston, USA and my
PC and 20" monitor heat my small 6' x 10' office(one exterior wall).  You'll
probably want the make-up outside air to be directed at your body and then
flow out through the electronics to carry the heat away.  I'd look into how
the F-16 does the ventilation and go from there.

      Regarding the air conditioner,  you can make the window unit work
without putting it in the window.  You could just let the heat dump in the
room and put a good exhaust fan in the window.  A better way would be to
mount it on a stand inside the room as close to the window as practicable.
You would then build a shroud over the exhaust louvers to(slits on sides and
top) to direct the hot air out of the window. Connect a medium sized fan to
the shroud with a large flex duct and attach the fan to the window bars.
There will also be condensation dripping from the air conditioner that will
have to be directed to a drain or bucket.

      Craig R.

      -----Original Message-----
      From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org]On Behalf Of Albert Yung
      Sent: Wednesday, November 24, 1999 1:01 PM
      To: simpits-tech@simpits.org
      Subject: Re: [simpits-tech] How do you deal with temperature inside
the pit?


        G'day Craig,

        Love your work, all those things you had mentioned are things that I
have not considered in great depth up to this point. Looks like if I was to
put a canopy on the pit. I will be jumping into a real deepend. This weekend
I was just drawing up plans for the hull and how I will have to construct it
differently if an enclosed canopy will be place ontop. Do you think its
worth while to be paranoi (like myself) to worry about all these things so
early on...or should I just go ahead and build the damn thing up then I can
get some realistic measures of T and RH inside the pit. Then I can figure
out if I need some sort of active cooling?

        The window air conditioner option is definetly out. I live in a
place where I wont even dare to stick a satellete dish out the window, it
will get knock off too easily. So my only mean to cool this room down is the
option of one portable air conditioner or evaporative cooler that does not
include an outdoor component to function.

        Thanks for making this sophiscated concept relatively simple to
understand.

        I will shot you a private email asap.

        Cheers,

        Albert
        p.s. Gene, I think this is definetly a good topic article for the
simpits.org site. What do you reckon?



          ----- Original Message -----
          From: Craig Rochester
          To: simpits-tech@simpits.org
          Sent: Monday, November 25, 2002 3:38 AM
          Subject: RE: [simpits-tech] How do you deal with temperature
inside the pit?


          Finally a question I'm qualified to answer. :) I do a lot of HVAC
in my work.

          Before you decide on cooling you should consider ventilation
first.  Your pit is basically a small room in a larger room. Here are the
basic details to evaluate:
            1.. What AC and or ventilation do you have in the room the pit
is in?  I.e. room size, AC air flow rate, AC air supply temperature(out of
duct).
            2.. What outside air conditions, Temperature(T) and Relative
Humidity(RH) does you location see summer/winter?
            3.. What clothing and/or helmet and mask equipment will you use?
            4.. If you use a "oxygen mask" where will the air come from and
where will it exhaust?
            5.. How much heat will be generated by the equipment in the pit?
          The RH is a very important parameter that is often overlooked.
The simplest way to get rid of the humidity and heat generated by you and
the equipment is to exhaust it out.  What goes out must be made up "Outside
Air Make-up"(OA) and this must be cold enough and dry enough to provide a T
and RH equilibrium that is comfortable.  IF the room's air is good enough to
provide sufficient OA to the pit all you need to do is have an exhaust
system(simple fan) with vents located to direct the OA air through the pit.

          If you room is too warm or humid to knock down the T/RH of the
pit, then active cooling is required.  If cost is important and you're
handy(if you can build a pit...) I'd use a regular window air conditioner
and build a shroud around the "evaporator" section, the part that goes
outside the window.  The shroud would be connected to a fan to blow the air
outside the room through the bars.  The room-side of the air conditioner
would be directed to the pit's OA make-up.

          I'd be glad to provide assistance in determining the details if
you wish.

          Craig R.
            -----Original Message-----
            From: simpits-tech-admin@simpits.org
[mailto:simpits-tech-admin@simpits.org]On Behalf Of Albert Yung
            Sent: Wednesday, November 24, 1999 10:16 AM
            To: simpits-tech@simpits.org
            Subject: [simpits-tech] How do you deal with temperature inside
the pit?


            Hi guys,

            This is a question especially for those of you who have or
planning on building an enclose cockpit (especially for the f16), i.e. with
a canopy. How do you deal with temperature that will bound to build up
within the pit?

            Heat generated from all the electronics, backlid panels, extra
monitors (If you are not using a projector) and your own body heat

            The only reason why I want to have a canopy is not for aesthetic
but for "Sound proofing" myself when I talk over RW (because I share room).I
dont want to "premanently" sound proofing myself by suffercating myself from
within the cockpit. Turning the pit into a coffin :)

            To make matter worse I live in a flat where I cant break any
walls to put in a ducted reverse cycle air cond... I have grills and bars on
my windows to keep out intruders so no way I can put in a wall/window
mounted air cond. My only hope would be a portable air conditioner or one of
those evaporative coolers...modify it and throw an inlet into the pit.

            My second question would be, evaporative coolers, are they any
effective in cooling the inner space of the f16 pit? because the price of
one of them is like 1/10 of a portable air conditioner.

            Would love to hear all of your thoughts :)

            Albert
            Sydney, bloody boiling in Austraila

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<BODY bgColor=3D#ffffff>
<DIV><SPAN class=3D234014623-25112002><FONT face=3DArial =
color=3D#0000ff>Here's a=20
rough sketch&nbsp;of the idea for a "widow" A/C connected to a pit: <A=20
href=3D"http://pages.zdnet.com/johncraigrochester/sitebuildercontent/site=
builderpictures/.pond/ac.jpg">http://pages.zdnet.com/johncraigrochester/s=
itebuildercontent/sitebuilderpictures/.pond/ac.jpg</A>.</FONT></SPAN><FON=
T=20
face=3D"Times New Roman"><SPAN class=3D234014623-25112002><FONT =
face=3DArial=20
color=3D#0000ff>&nbsp;</FONT></SPAN></FONT></DIV>
<DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
class=3D234014623-25112002></SPAN></FONT>&nbsp;</DIV>
<DIV><FONT color=3D#0000ff><SPAN class=3D234014623-25112002>Craig=20
R.</SPAN></FONT></DIV>
<DIV><FONT><FONT size=3D2><SPAN=20
class=3D234014623-25112002></SPAN></FONT></FONT>&nbsp;</DIV>
<DIV><FONT><FONT size=3D2><SPAN=20
class=3D234014623-25112002>&nbsp;</SPAN>-----Original =
Message-----<BR><B>From:</B>=20
simpits-tech-admin@simpits.org =
[mailto:simpits-tech-admin@simpits.org]<B>On=20
Behalf Of</B> Craig Rochester<BR><B>Sent:</B> Monday, November 25, 2002 =
5:45=20
PM<BR><B>To:</B> simpits-tech@simpits.org<BR><B>Subject:</B> RE: =
[simpits-tech]=20
How do you deal with temperature inside the =
pit?<BR><BR></DIV></FONT></FONT>
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff size=3D2>Hi=20
  Albert,</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2>Sorry for the tardy response, but work's real busy right; =
major HVAC=20
  project.&nbsp; I'm working on a "fill room" cleanroom.&nbsp; The room =
is 14' x=20
  15' x 9' tall and has 7,500 CFM air flow.&nbsp;&nbsp;The air is =
replaced in=20
  the room 4.5&nbsp;times a minute.&nbsp; The temperature is held to 65F =
+/- 1F=20
  and RH to 45%&nbsp; +/- 5%.&nbsp; The equipment could easily condition =
a=20
  couple of medium size houses.</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2>FWIW, here's some info on RH vs.. T:</FONT></SPAN></DIV>
  <DIV><FONT face=3DArial><FONT color=3D#0000ff><FONT=20
  size=3D2></FONT></FONT></FONT>&nbsp;</DIV>
  <DIV><FONT face=3DArial><FONT color=3D#0000ff><FONT size=3D2>H<SPAN=20
  class=3D609111121-25112002>ere's a link for the "psychrometrics" of =
air: <A=20
  =
href=3D"http://www.ianr.unl.edu/pubs/generalag/g626.htm#air">http://www.i=
anr.unl.edu/pubs/generalag/g626.htm#air</A></SPAN></FONT></FONT></FONT></=
DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2>Relative humidity is a measure of the moisture absorbed by =
air.&nbsp;=20
  Warm air can hold a lot more water than cold air.&nbsp; For a given=20
  temperature, the air has a maximum about it can absorb.&nbsp; The RH =
number in=20
  % is the amount water in the air divided my the maximum amount it =
could hold=20
  at that temperature(saturated).&nbsp; So when you heat up some air =
with a=20
  certain RH, the amount of water remains constant, but the RH goes =
down. Also,=20
  humidity "moves" differently than heat.&nbsp; Humidity will "migrate" =
from=20
  humid air to less humid air as pressure is the driving force(vapor=20
  pressure).</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff size=3D2>So=20
  why the RH sermon?&nbsp; It makes a real difference for a person's=20
  comfort.&nbsp; Our bodies cool by evaporative cooling(sweating).&nbsp; =
As the=20
  air becomes more humid, the sweat evaporates less efficiently&nbsp;to =
a point=20
  where we sweat faster than it dies and we get "sweaty" =3D =
uncomfortable.&nbsp;=20
  Also, as the sweat evaporates and we breath out moist air, the RH in a =
small=20
  space like a cockpit will increase to a point where the air is =
saturated and=20
  condensation will form on the cooler surfaces(stuff will fog=20
  up).</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff size=3D2>The=20
  problem with evaporative cooling is that the process adds moisture to =
the air,=20
  and in a closed room, the humidity will rise to a point where the =
cooler won't=20
  cool anymore(the fan will add heat).&nbsp; With room air conditions =
you gave,=20
  90F/30%, if you cooled this to 70F with evaporation you'd have about =
85%=20
  RH.&nbsp; That's sticky.</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff size=3D2>With=20
  a standard A/C unit(vapor compression) air is cooled to the point =
where the=20
  water condenses out(it drips out the bottom), and you get "free"=20
  dehumidification,.&nbsp; So not only do you cool the air, but you =
knock down=20
  the humidity, both together provide a comfortable feel.&nbsp; I like =
warm and=20
  dry better than cool and damp.&nbsp; My favorite conditions for low =
physical=20
  activity is 70F with 45% RH(max 50%).&nbsp; I might even drop that a =
bit when=20
  flying Falcon4, as bogeys are always on my butt.</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff size=3D2>A=20
  small "window" A/C, about 4,000 BTU(1500 kW),&nbsp;is about 18" x 20" =
x 14"=20
  tall.&nbsp; I've got two, both of which I got off the street(trash=20
  day)&nbsp;and worked after cleaning the coils.&nbsp;I'll draw a =
diagram to=20
  illustrate what I have in mind, if you're =
interested.</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2>Craig R.</FONT></SPAN></DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><SPAN class=3D609111121-25112002><FONT face=3DArial =
color=3D#0000ff=20
  size=3D2></FONT></SPAN>&nbsp;</DIV>
  <DIV><FONT face=3D"Times New Roman"><FONT size=3D2><SPAN=20
  class=3D609111121-25112002>&nbsp;</SPAN>-----Original=20
  Message-----<BR><B>From:</B> simpits-tech-admin@simpits.org=20
  [mailto:simpits-tech-admin@simpits.org]<B>On Behalf Of</B> Albert=20
  Yung<BR><B>Sent:</B> Thursday, November 25, 1999 2:39 AM<BR><B>To:</B> =

  simpits-tech@simpits.org<BR><B>Subject:</B> Re: [simpits-tech] How do =
you deal=20
  with temperature inside the pit?<BR><BR></DIV></FONT></FONT>
  <BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
    <DIV><FONT face=3DArial size=3D2>Hi Craig,</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>I invested in a half decent =
Hygrometer with=20
    in/out thermo reading. This will allow me to give you some good =
reading of=20
    my room.</FONT><FONT face=3DArial size=3D2>&nbsp;Also in the =
afternoon rush=20
    hour, I went to a electronic chain here just before they closed =
today...only=20
    saw the evaporative cooler. Cool my brain off first before I walk =
back out=20
    to the 84degree heat. With my newly purchase gadget, I can tell you =
today's=20
    relative humidity is 33% with a chances of a late shower...hehe. =
Today was=20
    the Hotest November night since 1988....in Sydney.</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Anyway, I agree with you. If the =
monitor are=20
    located inside the pit then it will dramatically increase the heat =
factor.=20
    Sucking outdoor air into the pit has been considered...but might not =
be=20
    possible to achieve. My room size is 12ft x 9ft. Brick wall facing =
north=20
    east and north west. Window is about 2.5ft by 4 ft.facing the north=20
    west.</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Architectural wise, this room get =
good use of=20
    natural sunlight and also get a good breeze from the door which =
directly=20
    face the window.</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Ok, here's the weather =
update...right now. its=20
    31degree C or 87.6 F in here...the back of 3 monitors is 99.7F&nbsp; =
the=20
    room's relative humidity was 37%. 8% lower than it was when I first =
entered=20
    the room with window shut...</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Unfortunately, it will be very =
impossible to=20
    mount a window unit on a stand...or anywhere in the room... There =
are a few=20
    floor standing evaporative cooler which kinda feel cool. I might get =
one of=20
    them since it only cost about 100USD. Try it out in my room and see =
how much=20
    they can cool the room for normal purpose. However, I do question =
the=20
    reading I got here 36% RH will prehaps make the Evaporative cooler =
less=20
    effective. </FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>I found an old fan which I can use =
maybe to=20
    provide suction out of the pit or blowing it into the pit. While =
other=20
    issues you mentioned I will get to them in a direct email to you=20
    :)</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Thanks a tonne for every bit of =
your advise=20
    mate! I can not do without them.</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV><FONT face=3DArial size=3D2>Albert</FONT></DIV>
    <DIV>&nbsp;</DIV>
    <DIV>&nbsp;</DIV>
    <BLOCKQUOTE dir=3Dltr=20
    style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
      <DIV style=3D"FONT: 10pt arial">----- Original Message ----- =
</DIV>
      <DIV=20
      style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
      <A title=3Djohncraigroch@msn.com =
href=3D"mailto:johncraigroch@msn.com">Craig=20
      Rochester</A> </DIV>
      <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dsimpits-tech@simpits.org=20
      =
href=3D"mailto:simpits-tech@simpits.org">simpits-tech@simpits.org</A> =
</DIV>
      <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, November 25, =
2002 5:48=20
      AM</DIV>
      <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> RE: [simpits-tech] =
How do=20
      you deal with temperature inside the pit?</DIV>
      <DIV><BR></DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002>Hi Albert,</SPAN></FONT></DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002></SPAN></FONT>&nbsp;</DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002>I think ventilation is important to =
consider in=20
      the design.&nbsp; Not only for your comfort, but for the =
reliability of=20
      the electronics.&nbsp; E.g.., if a monitor is in the pit, that's a =
lot of=20
      heat.&nbsp;&nbsp;I live in Boston, USA and my &nbsp;PC and 20" =
monitor=20
      heat my small 6' x 10' office(one exterior wall).&nbsp; You'll =
probably=20
      want the make-up outside air to be directed at your body and then =
flow=20
      out&nbsp;through the electronics to carry the heat away.&nbsp; I'd =
look=20
      into how the F-16 does the ventilation and go from=20
      there.</SPAN></FONT></DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002></SPAN></FONT>&nbsp;</DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002>Regarding the air conditioner,&nbsp; =
you can make=20
      the window unit work without putting it in the window.&nbsp; You =
could=20
      just let the heat dump in the room and put a good exhaust fan in =
the=20
      window.&nbsp; A better way&nbsp;would be to&nbsp;mount it on a =
stand=20
      inside the room as close to the window as practicable.&nbsp; You =
would=20
      then build a shroud over the exhaust louvers to(slits on sides and =
top) to=20
      direct the hot air out of the window.&nbsp;Connect a medium sized =
fan to=20
      the shroud with a large flex duct and attach the fan to the window =

      bars.&nbsp; There will also be condensation dripping from the air=20
      conditioner that will have to be directed to a drain or=20
      bucket.</SPAN></FONT></DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002></SPAN></FONT>&nbsp;</DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002>Craig R.</SPAN></FONT></DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002></SPAN></FONT>&nbsp;</DIV>
      <DIV><FONT face=3DArial color=3D#0000ff size=3D2><SPAN=20
      class=3D203072018-24112002></SPAN></FONT><FONT face=3D"Times New =
Roman"=20
      size=3D2>-----Original Message-----<BR><B>From:</B>=20
      simpits-tech-admin@simpits.org=20
      [mailto:simpits-tech-admin@simpits.org]<B>On Behalf Of</B> Albert=20
      Yung<BR><B>Sent:</B> Wednesday, November 24, 1999 1:01 =
PM<BR><B>To:</B>=20
      simpits-tech@simpits.org<BR><B>Subject:</B> Re: [simpits-tech] How =
do you=20
      deal with temperature inside the pit?<BR><BR></DIV></FONT>
      <BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
        <DIV><FONT face=3DArial size=3D2>G'day Craig,</FONT></DIV>
        <DIV>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>Love your work, all those =
things you had=20
        mentioned are things that I have not considered in great depth =
up to=20
        this point. Looks like if I was to put a canopy on the pit. I =
will be=20
        jumping into a real deepend. This weekend I was just drawing up =
plans=20
        for the hull and how I will have to construct it differently if =
an=20
        enclosed canopy will be place ontop. Do you think its worth =
while to be=20
        paranoi (like myself) to worry about all these things so early =
on...or=20
        should I just go ahead and build the damn thing up then I can =
get some=20
        realistic measures of T and RH inside the pit. Then I can figure =
out if=20
        I need some sort of active cooling?</FONT></DIV>
        <DIV>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>The window air conditioner =
option is=20
        definetly out. I live in a place where I wont even dare to stick =
a=20
        satellete dish out the window, it will get knock off too easily. =
So my=20
        only mean to cool this room down is the option of one portable =
air=20
        conditioner or evaporative cooler that does not include an =
outdoor=20
        component to function.</FONT></DIV>
        <DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>Thanks for making&nbsp;this =
sophiscated=20
        concept relatively simple to understand.</FONT></DIV>
        <DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>I will shot you a private email =

        asap.</FONT></DIV>
        <DIV>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>Cheers,</FONT></DIV>
        <DIV>&nbsp;</DIV>
        <DIV><FONT face=3DArial size=3D2>Albert</FONT></DIV>
        <DIV><FONT face=3DArial size=3D2>p.s.<FONT face=3DArial =
size=3D2> Gene, I think=20
        this is definetly a good topic article for the simpits.org site. =
What do=20
        you reckon?</FONT></FONT></DIV>
        <DIV>&nbsp;</DIV>
        <DIV>&nbsp;</DIV>
        <DIV>&nbsp;</DIV>
        <BLOCKQUOTE dir=3Dltr=20
        style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: =
5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
          <DIV style=3D"FONT: 10pt arial">----- Original Message ----- =
</DIV>
          <DIV=20
          style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
          <A title=3Djohncraigroch@msn.com=20
          href=3D"mailto:johncraigroch@msn.com">Craig Rochester</A> =
</DIV>
          <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A=20
          title=3Dsimpits-tech@simpits.org=20
          =
href=3D"mailto:simpits-tech@simpits.org">simpits-tech@simpits.org</A>=20
          </DIV>
          <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, November =
25, 2002=20
          3:38 AM</DIV>
          <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> RE: =
[simpits-tech] How=20
          do you deal with temperature inside the pit?</DIV>
          <DIV><BR></DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>Finally a question I'm qualified to answer. :) I do a =
lot of=20
          HVAC in my work.</FONT></SPAN></DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2></FONT></SPAN>&nbsp;</DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>Before you decide on cooling you should consider =
ventilation=20
          first.&nbsp; Your pit is basically a small room in a larger =
room. Here=20
          are the basic details to evaluate:</FONT></SPAN></DIV>
          <OL>
            <LI><SPAN class=3D415395515-24112002></SPAN><SPAN=20
            class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff size=3D2>What=20
            AC and or ventilation do you&nbsp;have in&nbsp;the room the =
pit is=20
            in?&nbsp; I.e. room size, AC air flow rate, AC air supply=20
            temperature(out of duct).</FONT></SPAN>=20
            <LI><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
            size=3D2>What outside air conditions, Temperature(T) and =
Relative=20
            Humidity(RH) does you location see =
summer/winter?</FONT></SPAN>=20
            <LI><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
            size=3D2>What clothing and/or helmet and mask equipment will =
you=20
            use?</FONT></SPAN>=20
            <LI><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
            size=3D2>If you use a "oxygen mask" where will the air come =
from and=20
            where will it exhaust?</FONT></SPAN>=20
            <LI><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
            size=3D2>How much heat will be generated by the equipment in =
the=20
            pit?</FONT></SPAN></LI></OL>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>The RH is a very important parameter that is often=20
          overlooked.&nbsp; The simplest way to get rid of the humidity =
and heat=20
          generated by you and the equipment is to exhaust it out.&nbsp; =
What=20
          goes out must be made up "Outside Air Make-up"(OA) and this =
must be=20
          cold enough and dry enough to provide a T and RH equilibrium =
that is=20
          comfortable.&nbsp; IF the room's air is good enough to provide =

          sufficient OA to the pit all you need to do is have an exhaust =

          system(simple fan)&nbsp;with vents located to direct the OA =
air=20
          through the pit.</FONT></SPAN></DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2></FONT></SPAN>&nbsp;</DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>If you room is too warm or humid to knock down the =
T/RH of the=20
          pit, then active cooling is required.&nbsp; If cost is =
important and=20
          you're handy(if you can build a pit...) I'd use a regular =
window air=20
          conditioner and build a shroud around the "evaporator" =
section, the=20
          part that goes&nbsp;outside the window.&nbsp; The shroud would =
be=20
          connected to a fan to blow the air outside the room through =
the=20
          bars.&nbsp; The room-side of the air conditioner would be =
directed to=20
          the pit's OA make-up.</FONT></SPAN></DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2></FONT></SPAN>&nbsp;</DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>I'd be glad to provide assistance in determining the =
details if=20
          you wish.</FONT></SPAN></DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2></FONT></SPAN>&nbsp;</DIV>
          <DIV><SPAN class=3D415395515-24112002><FONT face=3DArial =
color=3D#0000ff=20
          size=3D2>Craig R.</FONT></SPAN></DIV>
          <BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
            <DIV class=3DOutlookMessageHeader><FONT face=3D"Times New =
Roman"=20
            size=3D2>-----Original Message-----<BR><B>From:</B>=20
            simpits-tech-admin@simpits.org=20
            [mailto:simpits-tech-admin@simpits.org]<B>On Behalf Of</B> =
Albert=20
            Yung<BR><B>Sent:</B> Wednesday, November 24, 1999 10:16=20
            AM<BR><B>To:</B> simpits-tech@simpits.org<BR><B>Subject:</B> =

            [simpits-tech] How do you deal with temperature inside the=20
            pit?<BR><BR></DIV></FONT>
            <DIV><FONT face=3DArial size=3D2>Hi guys,</FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>This is a question =
especially for those=20
            of you who have or planning on building an enclose cockpit=20
            (especially for the f16), i.e. with a canopy. How do you =
deal with=20
            temperature that will bound to build up within the =
pit?</FONT></DIV>
            <DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>Heat generated from all the =

            electronics, backlid panels, extra monitors (If you are not =
using a=20
            projector) and your own body heat</FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>The only reason why I want =
to have a=20
            canopy is not for aesthetic but for "Sound proofing" myself =
when I=20
            talk over RW (because I share room).I dont want to =
"premanently"=20
            sound proofing myself by suffercating myself from within the =

            cockpit. Turning the pit into a coffin :) </FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>To make matter worse I live =
in a flat=20
            where I cant break any walls to put in a ducted reverse =
cycle air=20
            cond... I have grills and bars on my windows to keep out =
intruders=20
            so no way I can put in a wall/window mounted air cond. My =
only hope=20
            would be a portable air conditioner or one of those =
evaporative=20
            coolers...modify it and throw an inlet into the =
pit.</FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>My second question would =
be,=20
            evaporative coolers, are they any effective in cooling the =
inner=20
            space of the f16 pit? because the price of one of them is =
like 1/10=20
            of a portable air conditioner.</FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>Would love to hear all of =
your thoughts=20
            :)</FONT></DIV>
            <DIV>&nbsp;</DIV>
            <DIV><FONT face=3DArial size=3D2>Albert</FONT></DIV>
            <DIV><FONT face=3DArial size=3D2>Sydney, bloody boiling in=20
            =
Austraila</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE=
></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>

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