[Equest-users] HVAC sizing - triple vs. dual

[Haynes, Glenn]

During the summer peak wouldn't you expect the heat flow to be into the spaces from the outside?  You have been talking about times when the outside temperature is below the space set points for the free cooling effect.

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From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Alex Krickx
Sent: Tuesday, August 24, 2010 1:31 PM
To: Namrata Vora; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] HVAC sizing - triple vs. dual



Hi Namrata,

 

As I see it, there are 2 ways that glass affects energy: solar gains coming in (which is tied to the SHGC) and heat transfer through the unit (tied to the U-factor). If you substantially reduce the SHGC going from double to triple pane, then you may be losing some passive heating, thus increasing your boiler sizing (although I would expect it would have to be a substantial change in SHGC to outweigh the benefits of improved U-factor). As for U-factor: in a building with high-internal loads you may benefit in summer from excess heat being released through the glazing (as Vikram pointed out) - so this would increase your peak chiller capacity. That would not entirely surprise me, but I think an increase in boiler size is less typical.

 

My 2¢.

 

Cheers,

Alex Krickx

 

 

Alex Krickx

Building Energy Specialist

 

1250 Elko Dr, Sunnyvale, CA 94089

(t) 408.541.8124

 

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From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Namrata Vora
Sent: Monday, August 23, 2010 6:12 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] HVAC sizing - triple vs. dual

 

eQuest is showing for identical bldgs HVAC sizing for triple pane to be more than that for dual pane for cold climates like Edmonton. Is that normal?

 

 

Namrata 

Work: 408-263-9225

Cell: 408-893-3729

 

 

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