[Equest-users] Evaporative cooling

[Nick Caton]

Sambhav,

 

Do you mean roof-mounted swamp coolers (such as the attached example)?
I've designed around such units for well ventilated garages and similar
in hot, arid climates.

 

To answer your specific questions, assuming you're using similar
equipment:

1.       Right - this sort of equipment supplies effectively saturated,
100% outside air.  The OA fraction would be 1.0, and you would need
relief louvers and/or a corresponding exhaust system in the served
spaces, assuming it's enclosed.

2.       In my experience, the commercial units I've dealt with (smaller
units) are either constant volume or 2-speed fans at most (such
thermostats have a HI-LO option), but I can't think of a reason they
couldn't be otherwise.

 

I've never modeled swamp coolers in eQuest, so can't offer you any
specific advice to manipulating the program - I'd appreciate anyone with
such experience sharing how feasible it is to model such equipment, or
what pitfalls there may be...  

 

I'm thinking out-loud here, perhaps something special ought to be
considered for the corresponding thermostats to correctly model their
operating behavior - as the saturated air from a comfort perspective is
going to "feel" significantly warmer than the conditioned drybulb
temperature the thermostat would be operating off of... that's to say if
you want to model the units cooling until the air "feels" like 75F,
perhaps the drybulb thermostat setpoint in eQuest should be something
more like 70F?  

 


~Nick

 

 

 

NICK CATON, E.I.T.

PROJECT ENGINEER

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

Check out our new web-site @ www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of sambhav
tiwari
Sent: Wednesday, April 21, 2010 5:11 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Evaporative cooling

 

Hi Equestors,
            I am having a evaporative cooling system in my project and
having some doubts pertaning to that .First i would like to know weather
in a Evaporative cooling system the fresh cfm and supply cfm will be
same value? not like in other case where fresh cfm is a fraction of
suply cfm like 0.1 to 0.2.

Secondly weather the evaporative cooling is a constant or variable
volume system?

I shall be obliged if any one  can reply me on this.

Thanks
Sambhav Tiwari

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