Mechanical Systems Commissioning – Is independent third party required!!
ASHARE standard 90.1 – 2010 bases commissioning requirements on floor area. It requires commissioning for projects larger than 50,000 sq. ft except warehouses and semi heated spaces. It doesn’t prescribe any requirement for selection of commissioning team.
Unlike 90.1-10, 2012 IECC requires system commissioning based on the total building HVAC capacity for heating and cooling systems regardless of floor area. It requires commissioning on smaller buildings because of the total building threshold of 480,000 Btu/hr for space cooling and 600,000 Btu/hr output for space cooling. It also doesn’t prescribe any requirement for selection of commissioning team.
2012 IECC C408.3.1 states that “Where required by the code official, an approved party independent from the design or construction of the project shall be responsible for the functional testing and shall provide documentation to the code official certifying that the installed lighting controls meet the provisions of Section C405”. Essentially it is leaving the requirement for independent party on code official.
EAp1 LEED NC (2009) requires that all projects shall be commissioned. It is pre requisite. For projects less than 50,000 ft2, the CxA may be involved in the project as an associate of the contractor, construction manager, architect, or engineer and may have other project responsibilities. For projects over that size, the CxA may be still be from the same firm as a project team member, as long as he or she is not otherwise involved in the project. In both cases an independent consultant contracted to the owner is also an option, and may bring more value by offering better objectivity and a different perspective than someone associated with the design team. For the Enhanced Commissioning credit (EAc3), an independent consultant is required to be the CxA by LEED.
Codes have mandated the requirement for commissioning but they don’t dictate qualification of CxA. LEED requires an independent member of team for commissioning where project size exceeds 50,000 sq. ft. Enhanced commissioning credit requires an independent consultant to be CxA. Independent consultants are bring objectivity and different perspective to project but it comes at additional cost to owner. Several times on smaller renovation projects owner is already stressed for budget and it is hard to justify any additional cost for independent consultant.