I have a CI project which includes the following scope of work: Our project occupies 2 floors of an 8-story office building. There are two central rooftop VAV AHUs which serve all 8 stories. There is a main supply and return riser which taps off onto each floor. The actual scope for the tenant space will be the demolition and renovation of existing ductwork on only our two floors. We will be revising rezoning and laying out new VAV locations with hot water reheat coils.
In the Bird's Eye View narrative above it states "On Commercial Interiors projects, commissioning is required for all systems and equipment installed as part of the tenant’s project scope. This may include, for example, pumps from base building distribution systems, sub-metering equipment, controls, and air handlers"
Per the comment above by Chris Ladner, he states that "The commissioning requirements for LEED 2009 for Commercial Interiors apply to the "Tenant space" that is within the LEED project boundary. This means that commissioning of central systems installed in association with the core & shell portion of the project that are outside the "Tenant space" are not required to be part of the CI commissioning scope.
Both of these items seem to contradict each other which is correct?
Although the air handlers are not located in the tenant space are they still required to be commissioned? We also have air-cooled chillers and their associated pumps which supply chilled water to the AHUs. Do these need to be commissioned? We then have a HHW boiler and associated pumps which pump HHW via a main building riser and a piping loop on each floor to the reheat coils at the VAV box. Would these need to be commissioned? Do just the control vales need to commissioned? Do the pumps need to be commissioned? Or control vales, pumps and boilers? For rooftop exhaust fans which serve all floors and provide general exhaust to our floor (in addition to all others), does this need to be commissioned? The definition of scope is not clearly defined in any of the LEED reference guides or literature. One could argue that all of these systems contribute in someway to the HVAC in our space and would need to be commissioned.
Thanks.
Jan Wei
Director of Commissioning & Critical SystemEdwards & Zuck
44 thumbs up
October 5, 2010 - 4:51 pm
James,
The Bird's Eye View narrative is a broad description of the commissioning requirements. The reason for the description is due to various tenant fit-out projects and leased agreements, and the amount of control a tenant has on the base building system.
Keep in mind that most of the tenants do not have access or control to the base building system.
Most of the CI projects only involve adding few new equipments and relocating existing equipments, very few projects involve installation of new an entire independent HVAC systems (AHU, chillers, boilers, pumps, etc).
So LEED only requires CI project to commission the equipments under the tenant's project scope. Thurs the based building equipments and Core & Shell equipments do not apply.
So, based on your description of your project only the VAVs and asscoated control should included under the commissioning scope. But every good commissioning engineer has to consider and evaluate if tenant's HVAC system is compatible to the existing system layout, e.g., Does the existing AHU have VFD and duct static pressure control? How the tenant's equipment control is being integrated with the base builiding BMS (Building Management System)?
Also, do not forget that LEED requires the CI project to commission the HVAC system, lighting system, domestic HW system and any renewable system.
James Del Monaco
Sustainability Director, PEP2S Engineering, Inc.
64 thumbs up
October 6, 2010 - 11:13 am
Thanks Jan. Based on your analysis, i would agree that only the VAVs and associated controls should be included under the commissioning scope as far as HVAC goes. The AHUs, chillers, etc are all part of the base-building system and we do not necessarily have access to them. That equipment is maintained and controlled by the base building facilities staff.
I am also aware that DHW, lighting and renewable systems would be included. Those systems would fall under a similar evaluation as to what is base building and what is tenant scope.