Helpful hints - Back to Basics™

Engineered Systems, March, 2004 by Howard J. McKew

* This test is continued from the January and February 2004 issues.

* Integral to the long term success of a building system is the initial commissioning process followed by proactive building management. The cornerstone to this aggressive business plan is a project-ready CMMS system (check out www.esmagazine.com for the "My Project Is CMMS Ready" webpage).

* Optimizing building automation capabilities is seldom achieved by most facilities. Instead, energy, management it more often reactive, and sometimes consists of manually turning equipment on and off based on limited data collection.

* A BAS computer operator, assigned full time to maximize the EMS, can maximize the ROI and reasons why this BAS computer engineer is hired. The ROI can be anywhere from three years to less than a one year payback, based on the building use, systems used, and how aggressive the BAS computer engineer is at her job.

* Like any quality process, data collection and data analysis are the foundation to peak facility management as it relates to energy, consumption, operating cost, and maximizing of useful equipment service life. BAS trending, by using graphical presentations, can be invaluable to the facility management striving to educate others who need to know what operation and maintenance is responsible for. A picture is worth 1,000 words. A BAS computer graph can be worth even more.

* Trending energy consumption and mechanical and electrical equipment and system performance can be an integral part of LEED[TM] certification for new construction (the additional commissioning point), as well as an integral part of this certification for existing facilities.

Design Phase:

* In addressing energy management capabilities in the design phase, standard office specifications need to be enhanced to reflect today's business tools. The design engineer needs to work closely with the facility engineer to determine what metering and control components are required for the facility engineer to efficiently and effectively do his job. The same can be said for specifying the expanding of an existing CMMS system or specifying the extending of the facility manager's existing CMMS system so that planned maintenance workorders are available on day one occupancy.

* If energy simulation software is used for documenting the underfloor system performance, this month-by-month energy consumption should be used to benchmark trending data during the warranty phase of the project. This simulation exercise can also be used to obtain two to eight LEED' credit points based on computer output.

Commissioning Phase:

* Verification of software programming needs to be reviewed by the commissioning firm and the facility manager to understand the methodology that went into establishing the formulas and programming associated with energy management and system trending.

* When commissioning the computer software programs, it is important that the commissioning firm have access to the flow diagram (control logic) at part of the functional performance testing procedures.

* When commissioning/observing terminal equipment performance, it is recommended that only a small percentage (e.g., 15% or 20%) of this equipment be commissioned. The intent it to minimize commissioning cost by randomly selecting the number of (reheat coils, fancoil units, VAV terminals) placing the burden of proof of satisfactory performance on the contractor for all the terminal equipment.

* If 100% of the randomly checked terminal equipment commissioning pass, it can be assumed that the other terminal equipment will also pass. If there is failure of one or more underfloor terminals, the contractor will need to address this deficiency before demonstrating another 15% of the equipment at a cost to the contractor for the additional commissioning services.

* The commissioning team for this month's application should include the commissioning firm, the owner's project manager and BAS computer engineer, the BAS contractor (which may include HVAC equipment computer engineers), and mechanical trade contractor.

* When observing the BAS computer, functional performance test the commissioning firm will need to have a commissioning engineer at the computer and another commissioning engineer or technician at the end devices to observe "action-reaction."

Design criteria document:

* Space temperature: heating, 60[degrees]F unoccupied cycle and 70[degrees] occupied cycle; A/C, 80[degrees] unoccupied cycle and 76[degrees] occupied cycle.

* Occupied cycle: 8 a.m. to 7 p.m. (Monday-Friday) and 7 a.m. to 2 p.m. (Saturdays).

* CHW supply at 45[degrees] to 50[degrees] (reset control) and return at 56[degrees].

* HW supply at 180[degrees] and return and 150[degrees].

* Supply air: 55[degrees] to 65[degrees]; external static pressure: 0.5 in.

* C[O.sub.2] level not to exceed 800 ppm.

* Space rh: 30% to 55%.

Trending setpoints:

* Carbon dioxide ventilation level: C[O.sub.2] in ppm.

* Space humidity level: rh, space temperature, outdoor air temperature, and supply air temperature.