[Bldg-sim] UPS Heat of rejection. (UNCLASSIFIED)

Nick Caton ncaton at smithboucher.com
Tue May 31 12:19:23 PDT 2011


Hey John,

All power passes through a charged UPS on a day-to-day
(nonemergency/standby) basis for protected equipment... and this has a
heat loss that's a % of what's drawn hour-to-hour.  Grab a cutsheet to
try and to find the efficiency figure:  

(From http://www.tekexcel.com/esteemating.htm)

"... the inefficiency or power loss of a UPS will be in the range of 2%
to 20% and this is the fraction of the input power that will be turned
into heat. The percent power loss of different types of UPS depends
primarily on the design topology and can be estimated using the
following guide:

Small Standby UPS 	3%
Line Interactive UPS 	4%
Double Conversion On-Line UPS 	15%
Delta Conversion On-Line UPS 	5% "

~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 


-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eurek, John
S NWO
Sent: Tuesday, May 31, 2011 12:28 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] UPS Heat of rejection. (UNCLASSIFIED)

Classification: UNCLASSIFIED
Caveats: NONE

All,

I have a project with an UPS room (Uninterruptible Power System).  I was
give
the full load heat rejection.  

As I understand the UPS system, it is a battery back-up in emergencies.
So
the rest of the time the UPS would be in a trickle-charger type mode.
When I
model the UPS as being in full load heat 24hrs-365day if become a very
large
percentage of my building.  

What can I assume for the tickle-charger mode?  (I'm going to assume
"Emergencies" happen so seldom that it isn't worth scheduleing. So my
model
would have the UPS always in stand-bye mode.... you know, in an attempt
to
reflect reality.)

John

Classification: UNCLASSIFIED
Caveats: NONE


_______________________________________________
Bldg-sim mailing list
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
To unsubscribe from this mailing list send  a blank message to
BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG



More information about the Bldg-sim mailing list