[Equest-users] Humidifier

Nick Caton ncaton at smithboucher.com
Mon May 23 14:41:38 PDT 2011


Hrmmm...  No straight answers, but few questions have I!

 

Humidifier isn't running? With no outside air and little/no exhaust ...
seems to me the moisture present at the beginning of the simulation
isn't ever leaving the space - so why supply more moisture?  The
dehumidifier is probably only removing the moisture from the people
also, so I expect it's not major.  You might get different results if
you specify "OA from system"  with a corresponding minimum quantity, if
in the real world new, moisture-ridden/barren air is introduced from
other spaces.

 

Coil size off?  If the simulated design loads do check out (check
reports), keep an eye on the specified/calculated CFM as well.  Note
project altitude may mess with you in this regard if you're specifying.
Also:  90kW*3413/12,000 = about 35.8 tons, so 36 is probably the floor
for what to expect.  Also:  90kW is an important number, but equally
important is the schedule... is that running @ 100% 24/7 or for a single
hour at a time?  You'd end up with different coil sizes I bet.

 

And just for fun... I just found a Yoda-speak translation tool
<http://www.yodaspeak.co.uk/index.php> :

 

Coil size off, hmm?  If check out (check reports), the simulated design
loads do, as well keep an eye on the specified/calculated cfm.
Specifying, note project altitude may mess with you in this regard if
you are.  Also:  90kw*3413/12,000 = about 35.8 tons, so probably the
floor for what to expect, 36 is.  Also:  An important number, 90kw is,
but the schedule, equally important is...  For a single hour at a time
is that running at 100% 24/7 or, hmm?  End up with different coil sizes
I bet, you would.  

 

~Nick

 

 

NICK CATON, E.I.T.

PROJECT ENGINEER

Smith & Boucher Engineers

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Rob
Hudson
Sent: Monday, May 23, 2011 3:21 PM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Humidifier

 

After more putzing around, i have notices that if you set the OA to 0
then you cannot humidify, so i set it to 1 cfm, and now it works...

 

Cooling coil is still bothering me though.

On Mon, May 23, 2011 at 3:30 PM, Rob Hudson <rdh4176 at gmail.com> wrote:

I have an Equipment Rack Room (ERR) that has a chilled water/hot water
single zone system, with de-humidification and humidification.  When i
try to model this, i enter in the appropriate inputs into the system and
zone levels, and then for humidification i enter in my design
parameters, 60% and 35% with electric cansister humidifier type.  

 

My problems begin now, when i run the model the humidifier is never
turning on throughout the year, and dehumidification seems to work just
fine.  Also the program is currently sizing my cooling coil to a size
much larger than previously determined by hand.  

 

More notes:  the Rack load is 90kW with minimal other loads (lights and
people).  99% sensible heat ratio.  Using this i need about 30 tons of
cooling, which translates to a coil that should be slightly larger than
that, due to de/humidification.  my thermastat is set to 72deg and
design temperature is also 72 deg.

 

This has been alluding me for about 2 hours, so any help is appreciated.

-- 
Rob Hudson




-- 
Rob Hudson

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