Automated Commissioning for Energy (ACE) Platform for Large Retail Property. Overview

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Damian Elliott
8 years ago
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1 Automated Commissioning for Energy (ACE) Platform for Large Retail Property $62,900 dollars of energy savings identified during the first 6 weeks Overview The ability to pull large amounts of complex data from any BMS, sensor plus AHUs to automatically identify faults in advance of major problems allows large properties to run optimally David Walsh, Chief Executive Officer, CIM Environmental Group The traditional approach to improving the performance of HVAC plant and equipment is manual commissioning. Commissioning is a quality assurance process for setting up equipment to work safely, efficiently and in accordance with the manufacturer s recommendations while meeting the building s performance objectives specified by the services design engineer. This process delivers savings but it has limitations; 1) Cost - commissioning is typically $15-18k per site 2) Time reports often take 6-10 weeks to create 3) Continuity faults that occur after commissioning are not identified and energy wastage occurs The ACE Platform is different as it interfaces with all the BMS, energy management systems, HVAC equipment for automatic data collection and fault detection plus diagnosis. It detects, monetises and prioritises system faults. Conditions, energy consumption and maintenance costs are improved.

2 The ACE Large Retail Property Once the software was deployed on the Large Retail Property and live data was being analysed our engineering team were able to pinpoint systems that were performing outside of acceptable tolerances. Our engineering team in conjunction with the LARGE REIT operations manager were able to intelligently assign technical resources to address system issues on a prioritised basis. The below image shows the ACE Platform s technical output. Figure 1 Dynamic Fault Detection & Large Shopping Centre What faults were detected and what are the fixes? 1. HVAC System Imbalance a. Solution - The HVAC plant is operating significantly harder than required. There is an excess of cooling supplied at multiple points in the shopping centre. Some AHUs are calling on the boilers in order to off-set the cooling to meet the set point. An overall mechanical balance of the system, particularly in the tower, is required to reduce the amount of cooling and delivers even temperature across the floor plate without requiring the boilers to operate. Once an energy balance has been performed, this will enable the boilers to be locked out in summer. 2. Set Point Optimisation a. Solution - Investigate increasing the set point of the chilled water higher than 6 degrees. Typically this can be done for 9 months of the year, March to November.

3 Ensure that the CHWST set point is reset upwards until the valve controlling the coil that requires the most cooling is wide open. This strategy ensures that no coil is starved. 3. Sensor Optimisation a. Solution - Investigate the position and reading of all temperature sensors. One sensor (Angus & Coote) in the mall is positioned directly under a light. This sensor will be reading warmer than ambient temperature in the zone causing additional cooling requests. 4. Night Purge a. Solution - The internal mall temperature approaches 25 degrees after hours. A night purge will reduce the internal temperature by sucking in cool outside air during the early morning. Typically a night purge only needs to run the Supply Fans and Outside Air Fans for mins when outside air meets the criteria. This will reduce the chiller load and cooling demand in the morning. 5. Dead Band Optimization a. Solution - HVAC dead bands should be increased (heating and cooling). Currently the system is very sensitive and the hot water valve is opening with only a 0.1 degree below set point. This means the HVAC is regularly cycling between heating and cooling. Example: During the middle of the day 45% of hot water valve open, room temp 21.7 degrees. Figure 1 - System cycling caused by dead band set points 6. Outside Air Optimisation

4 a. Solution - Outside air is restricted in the tower AHUs. One solution is to increase the diameter of air flow ducts. Another option is to investigate increasing the speed that air flows down the duct by installing a fan to increase pressure in the air duct. This should be investigated as a part of a mechanical contractor s review and balance on site. 7. VSD Calibration a. Fault on VSD - AHU L3M-02. VSD was cycling every few seconds between 30 and 38 Hz. 8. Valve Fault Figure 2 - VSD fault a. Fault on AHU L3M-04. Chilled water valve is reading as closed in the BMS when it is in fact open. 9. Damper Fault a. Fault on supply damper Shop N141. Shop N141 (Subway) is being delivered 15 degree air. The supply air damper reads shut when it is open. 10. Maintenance Cycle a. Dirty filters on AHUs as shown in the BMS. These include: AHU L1E, AHU L2W, AHU L3W, AHU L3M-01, AHU L3M-02, AHU L3M-07, AHU L4W, AHU L5-01.

5 What s the benefit to the Large Shopping Centre? Financial benefit # Issue Savings ($) / Year Outcome 1 HVAC Balancing $ 32,000 15% reduction off HVAC load 2 Dead band optimisation $ 10,800 5% reduction off HVAC load 3 Set Point Optimisation $ 10,500 10% reduction off chiller load 4 Water Valve Fault $ 2,150 2% reduction off chiller load 5 Night Purge $ 2,150 2% reduction off chiller load 6 Outside Air Optimisation $ 2,150 2% reduction off chiller load 7 Sensors Optimisation $ 1,050 1% reduction off chiller load 8 Supply Damper Fault $ 1,050 1% reduction off chiller load 9 Dirty Filters on AHUs $ 1,050 1% reduction off chiller load 10 VSD Cycling Fault - Equipment optimisation Total Savings $ 62,900 Improved Conditions o Hot and cold complaints are caused by equipment faults and incorrect manual adjusting of set points. The ACE Platform will continuously identify when these faults and adjustments occur. Better NABERS rating o Over the coming months we will work with the onsite team to identify the exact benefit in the NABERS star rating due to the performance improvements. Critically any NABERS improvement can be easily maintained when faults are identified and fixed quickly. Greater Equipment Life Cycle o Chillers, pumps, fans and AHUs are all have a lifecycle timeline provided by the manufacturer. The lifecycle of plant and equipment is decreased due to excessive run times and faulty operation. The ACE Platform will greatly improve this and we are happy to provide a case study on the benefit over the coming months.

6 Conclusion The ACE Platform is delivering reduced energy consumption. The below image demonstrates a 14% reduction on two days with similar temperatures. Dollar savings Figure 3 14% reduction in energy consumption The installation of the ACE Platform on the Large Shopping Centre was a trial site. If Large REIT were to consider a portfolio wide installation the approximate costs is a setup cost of between $8,000-$14,000 ex GST per site depending on location and the amount of plant and equipment. The monthly cost for the dynamic monitoring of the site would range from $1,200 - $1,700 ex GST. These costs include an annual site visit by an engineer to execute additional onsite performance investigations. Our Guarantee We will guarantee that the ACE Platform will always deliver LARGE REIT a cost negative solution. We will compare the energy savings achieved versus the costs associated with the software, if the costs are greater than the savings we will refund the gap. Our standard terms and conditions would also apply. Therefore LARGE REIT will be certain of improving tenant conditions, NABERS ratings, maintenance costs and equipment lifecycle with absolutely no risk of an increase in outgoings.

Scope of Work. See www.sei.ie for resources available

Scope of Work. See www.sei.ie for resources available HVAC SWG Summary Background Pool energy-efficiency knowledge Increase cost-competitiveness Develop resources aimed at assisting in reducing HVAC energy consumption Address barriers to energy-saving HVAC