[Equest-users] peak heating demand

[deepika khowal]

Thanks Alex
I think the explanation you gave was very clear.
so when we design HVAC system, which loads we should consider?
for windows with better R-values, the peak load may b lesser but its overall
annual demand will be higher.
how to account for this in HVAC sizing?


On Wed, May 18, 2011 at 12:02 PM, Alex Krickx
<akrickx at seriousmaterials.com>wrote:

> Hi Deepika,
>
>
>
> I’m not sure how eQUEST calculates loads, but I can imagine a scenario
> where your results make sense:
>
>
>
> Peak heating load probably happens at night/early in the morning, right? So
> it probably depends on insulation (R-value) and not solar gains (SHGC). My
> guess is the window with the higher peak demand has low R-value (since you
> need lots of heat to make up for losses). But this window could have a high
> SHGC, so when the sun is out you benefit from passive heating (and have
> lower annual heating demands).
>
>
>
> I’m guessing your other window (with lower peak heating) has a better
> R-value - it retained heat better. This window may have a lower SHGC
> (possibly due to additional low-e coatings) and so it get less passive
> heating throughout the year and needs more heat to be added to the building
> during daytime hours.
>
>
>
> This will depend on the windows you’ve modeled, building type and climate.
> Perhaps if you share some more info on the project the answer will present
> itself.
>
>
>
> Regards,
>
> Alex Krickx
>
>
>
> Alex Krickx, LEED AP
>
> Building Energy Specialist
>
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> *From:* equest-users-bounces at lists.onebuilding.org [mailto:
> equest-users-bounces at lists.onebuilding.org] *On Behalf Of *deepika khowal
> *Sent:* Wednesday, May 18, 2011 11:19 AM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] peak heating demand
>
>
>
> Hi all
>
> I am modeling the performance of different glazing types in a building.
>
> I realized for one glazing, the peak gas demand is lower than other glazing
> but total heating energy is higher?
>
> how does equest calculate these loads and energy?
>
> Thanks
>
>
>
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