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ASHRAE 90.1 2010 Baseline systems for a mall building

asked 2023-04-14 10:40:36 -0500

jferamo89's avatar

updated 2023-04-16 05:48:00 -0500

Hi there,

I am currently working on an energy model for Mall building with tenants for a LEED CS certification compliance. I am struggling to figure out what Is the best method or process to assign the baseline systems to my thermal zones. In the mall there are quite a bit of different activities: cinema (>4000m2), F&B (kitchens), anchor fashion (>2500m2), >150 retail units (100-400m2 each), mall concourse(>19000m2), spa, fitness center, leisure, offices, server rooms, department store (>7000m2), supermarket, among others.

According to ASHRAE 90.1 2010 following the section G3.1.1 Baseline HVAC System Type and Description I assume the following:

-Retail units + supermarket -> System 7 (one single centralized HVAC unit with several zones?) or System 3 (one HVAC system per thermal block?)

-Department store -> System 5 (one HVAC system per floor, the department store has 2 levels, 2 HVAC system 5 in total?)

-Cinema -> System 5 (one HVAC system per floor, the cinema has 2 levels, 2 HVAC system 5 in total?)

-Mall concourse -> System 7 (one HVAC system per floor, the mall concourse has 3 levels, 3 HVAC system 7 in total?)

-Server rooms -> System 3 (one HVAC system per thermal block)

-Anchor fashion -> System 3

-F&B (Kitchen) -> System 5 or 7 (one HVAC system per kitchen?)

Are my assumptions correct?

This is quite confusing, on the other hand ASHRAE 90.1 2010 G3.1.1 proposed to group floors with identical thermal blocks, does this mean that for the system 5 and 7 above I only need one single system and I can group the zones, this contradicts with the previous "For systems 5,6,7,8,9 and 10 each floor shall be modeled with a separate HVAC system.

Could you provide me some feedback regarding this issue? Have you faced a similar case before, how did you address it?


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answered 2023-04-14 19:40:41 -0500

Keigo's avatar

Not confusing. All the conditioned spaces in your mall building should be System 7 as per TABLE G3.1.1A because your mall building is Nonresidential and the Total Floor Area exceeds 14000m2.

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I see. However, and due to the different type of activities according to ASHRAE 90.1 2010 G3.1.1 Additional system types for non predominant conditions should be use if those conditions apply to more than 1900m2 of conditionate area. That is anchor fashion, cinema and department store as defined above should have a system of their own. Furthermore, exceptions for server rooms and kitchen apply, would these spaces not have an independent HVAC system too?


jferamo89's avatar jferamo89  ( 2023-04-16 05:44:47 -0500 )edit

Anchor fashion, cinema and department store are all Nonresidential. System 7 should be modelled.

Kitchen is also System 7. For server rooms, you can use System 3 if the Exception b applies.

Keigo's avatar Keigo  ( 2023-04-16 06:03:47 -0500 )edit

In oder to determine the power of the HVAC system. Should I consider the total of all the spaces? or I create one single HVAC System 7 for each of them, that is one System 7 for the cinema, one for the anchor fashion, and one for the department store. Thanks

jferamo89's avatar jferamo89  ( 2023-04-17 02:46:54 -0500 )edit

You can refer to this post. As a minimum, you should model one System 7 on each floor. And you should further separaete System 7 as per the space types you mentioned (cinema, anchor fashion, department store) if the thermostat setpoint, the operation hours or the pressure drop adjustment varies by the space types.

Keigo's avatar Keigo  ( 2023-04-17 03:28:48 -0500 )edit

Thank you! That is very clear.

jferamo89's avatar jferamo89  ( 2023-04-17 04:47:22 -0500 )edit

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Asked: 2023-04-14 10:40:36 -0500

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Last updated: Apr 16 '23