[Equest-users] evaporative coolers in equest

[Patrick J. O'Leary, Jr.]

i would agree with nick on this except for part #3.  if you're using 
ashrae 62, or the 2000/2003/2006 imc (at least the way it is enforced in 
southern arizona), the evaporative cooler fan is required to run while 
the building is occupied so despite glazing upgrades you shouldn't be 
seeing any savings from the hvac system during occupied hours.  you 
would probably see some during night setback if the building there's 
some thermostat setting that will operate the evap coolers to remove air 
(and the associated heat build up) but i would not think it to be that 
significant of a savings compared to heat gain during occupied hours.

i would think, as nick mentions in point 5, that the ummet cooling hours 
might be a better measure of what you are looking for.  improved glazing 
should help reduce the rate of heat gain so the evap coolers should be 
able to meet whatever setpoint you are using with less unmet cooling 
hours.  in reality i would think it would be more obvious by an occupant 
working proximity to the windows - if they're currently affected by the 
solar heat gain.  i don't know your climate but in southern arizona you 
don't really want to be seated right next to a window with a direct sun 
exposure and insufficient airflow (evap) or mechanical cooling and poor 
windows.

On 8/16/11 2:22 PM, Nick Caton wrote:
>
> I hope we're at a simple vocabulary disconnect here...
>
> · Upgrading the windows will reduce your solar cooling loads.
>
> · Reducing your solar cooling loads will reduce the amount of heat to 
> be removed from the building.
>
> · Reducing the amount of heat to remove will reduce the required hours 
> of operation of your HVAC system (in this case, evaporative coolers) 
> to maintain comfort.
>
> · Reducing the runtime of your evaporative coolers will result in 
> reduced energy consumption.  Fan energies primarily, in the case of 
> evaporative coolers.
>
> · In the event the existing system is not of sufficient capacity to 
> begin with, you may also/instead observe a reduction in unmet cooling 
> hours.
>
> The reduction of solar loads with a glazing upgrade could be 
> /negligible/ for a variety of possible reasons, but it's unlikely the 
> net effect is absolutely zero.
>
> ~Nick
>
> cid:489575314 at 22072009-0ABB**
>
> * *
>
> *NICK CATON, P.E.***
>
> SENIOR ENGINEER
>
> Smith & Boucher Engineers
>
> 25501 west valley parkway, suite 200
>
> olathe, ks 66061
>
> direct 913.344.0036
>
> fax 913.345.0617
>
> www.smithboucher.com_ _
>
> *From:* deepika khowal [mailto:deepika.khowal at gmail.com]
> *Sent:* Tuesday, August 16, 2011 3:11 PM
> *To:* Nick Caton
> *Cc:* equest-users at lists.onebuilding.org
> *Subject:* Re: [Equest-users] evaporative coolers in equest
>
> This is an existing building with evaporative coolers.
>
> the proposed design  to upgrade the windows and check the relative 
> benefits.
>
> I dont see much benefits in energy because  evaporative coolers are 
> sized based on Cfm and not btus, the savings will be in cfms.
>
> correct me if I am wrong.
>
> is there any other way I can show the benefit in the proposed case if 
> not HVAC benefits?
>
> Thanks
>
> On Tue, Aug 16, 2011 at 1:00 PM, Nick Caton <ncaton at smithboucher.com 
> <mailto:ncaton at smithboucher.com>> wrote:
>
> Hi Deepika,
>
> I'm not certain any increase/decrease in cooling loads (such as solar 
> loads affected by changing glazing) should have any effect on the 
> reported "space cooling energy" when you're using evaporative 
> coolers.  Direct evaporative (swamp) coolers of the simplest sort have 
> only fan and pump energies to consider -  no refrigerant!  I would 
> advise looking up the Detailed Simulation Reports Summary page 158/160 
> to review end use categories and what they cover.
>
> I am unfamiliar with Bridgeport's climate, but as a general rule if I 
> observed a significant amount of glazing in a space served by a direct 
> evaporative cooler... I'd be extra cautious to ensure the HVAC 
> designer is carefully considering condensation and potential for other 
> humidity-driven issues along the way.  I'm most used to seeing them 
> applied to well-ventilated and/or open-air spaces such as garages and 
> gyms/hangars.
>
> ~Nick
>
> cid:489575314 at 22072009-0ABB
>
> * *
>
> *NICK CATON, P.E.*
>
> SENIOR ENGINEER
>
> Smith & Boucher Engineers
>
> 25501 west valley parkway, suite 200
>
> olathe, ks 66061
>
> direct 913.344.0036 <tel:913.344.0036>
>
> fax 913.345.0617 <tel:913.345.0617>
>
> www.smithboucher.com <http://www.smithboucher.com>_ _
>
> *From:* equest-users-bounces at lists.onebuilding.org 
> <mailto:equest-users-bounces at lists.onebuilding.org> 
> [mailto:equest-users-bounces at lists.onebuilding.org 
> <mailto:equest-users-bounces at lists.onebuilding.org>] *On Behalf Of 
> *deepika khowal
> *Sent:* Tuesday, August 16, 2011 1:36 PM
> *To:* equest-users at lists.onebuilding.org 
> <mailto:equest-users at lists.onebuilding.org>
> *Subject:* [Equest-users] evaporative coolers in equest
>
> Hello all
>
> I am modeling a building in Bridgeport, CA which has evaporative coolers.
>
> I dont see any benefits if I replace existing clear glass with low-e 
> in cooling energy consumption.
>
> Did anyone model evaporative coolers/swamp coolers before?
>
> I want to know whether there is a way to show cooling benefit with 
> such HVAC system.
>
> Thanks
>
> Regards
>
> Deepika
>
>
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