Monitoring and benchmarking of HVAC system efficiency

Transcription

1 Inspection of HVAC systems through continuous monitoring and benchmarking Monitoring and benchmarking of HVAC system efficiency Professor Ian Knight iserv Coordinator REHVA Annual Conference, Dusseldorf April 30 th 2014 The sole responsibility for the content of this presentation lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EACI nor the European Commission are responsible for any use that may be made of the information contained here.

2 What s at Stake? Potential annual EU savings of 6Bn+ and 60TWh+ Use of measured data to inform design Use of measured data to inform operation in detail 2

3 iservcmb overview Related to benchmarking, iservcmb is: A method for understanding and linking meters, HVAC components and building spaces A method for collecting detailed data for these elements Collecting and analysing sub-hourly data for real HVAC systems Producing novel power and energy in use benchmarks from this information 20/05/2014 3

4 Project data sources 11 Member States 257 Buildings 1,854 HVAC Systems 5,657 HVAC Components 1,611 Meters 7,749 Spaces 71 Activity types 1,242,289 Total floor area m 2 4

5 Stages of benchmarking Understand the building, meters and systems iserv spreadsheet Clarify what serves where and precise spaces served Separate occupants use Produce normalised energy data for these uses Understand what the building uses Produce normalised energy data for HVAC components Compare with other buildings Produce benchmark ranges obtained across buildings 20/05/2014 5

6 Why are benchmarks needed? All end uses Main utility meter submetered, data showing where energy is going Should we take any action? Still doesn t tell us whether the quantities consumed are reasonable HVAC Submeter HVAC - 33% Uncertainty Uncertainty about about end use end use 100% 67% 20/05/2014 6

7 Benchmark against others 20/05/2014 7

8 Overview of basic process Initial Data Entry via Excel sheet Meter/ sensor data Utility costs/ tariffs - GBP/EUR/etc iserv web database and analysis software Reports ECOs Benchmarks

9 Data COLLECTION spaces, activities, meters, HVAC Approach requires more precise calculation of area served by each component along with standard activity types Minimise uncertainty by minimising errors in the data Excel based framework for describing HVAC components, spaces, activities and meters. Compatible with BIM approach 9

10 Data COLLATION Incoming Meter Meter 1 Meter 2 Meter 3 The Connect meters, the spaces HVAC meters and systems components to HVAC the HVAC to systems the to components spaces the are systems now they described and serve they spaces serve and they connected serve Chillers CHW pumps HVAC System 1 Room 1 Room 2 Describe the spaces and activities in the building Describe HW pumps the Describe meters in the HVAC building, components in the building, including their including physical their locations physical locations Room 3 Meter 4 Meter 5 AHU 1 AHU 2 Boilers HVAC System 2 Room 4 Room 5

11 Hurdles and errors RICS Gross Internal Area used. Likely error of -1 to +4% of the recorded floor area value across Europe For meters, the data usually allows wrongly installed meters to be identified quickly. ±2% allowed for verified data. Current largest likely error is uncertainty over exactly what energy end uses each meter serves. Initial benchmarks reveal need for further information on occupancy and temperatures in some instances. There is also a need to separate process loads in the building, particularly IT loads. These should be metered separately and assessed using PUE calculations. 11

12 Benchmarks At HVAC component level, normalised by m 2 and activity Ranges of energy use or power demands being achieved Ranges of achieved performance benchmarks allow prediction of potential energy and cost savings. Central to much existing and future legislation, as well as helping reduce risk in design. 12

13 Benchmark types HVAC component serving a specific end use activity: Annual energy use in kwh/m2 Monthly energy use in kwh/m2 Power in use in W/m2 Not all benchmarks work well with floor area as the normalising metric. 13

14 Benchmarks from measured data The table shows measured normalised power demands for the AHU Component type for the UK Can be seen that the spread is quite large for many figures, reflecting real design and operation Air Handling Units Activity Name AVG W/m2 SD Assembly areas / halls Catering: Eating/drinking area Catering: Full Kitchen Preparing Hot Meals Catering: Kitchenette (small appliances, fridge and sink) Catering: Limited Hot Food Preparation Area Catering: Snack Bar with Chilled Cabinets Catering: Vending Machines Cellular Office Area Cellular Office Area - multiple occupation Circulation area (corridors and stairways) Consulting/treatment room IT: High Density IT Suite IT: LAN Rooms IT: Server Room Laboratory Laboratory with fume cupboards Lecture theatre Library - open stacks Library - stacks and storeroom 0.38 Lifts Light Plant Room Lounges Meeting Room Open Plan Office Area Reception Recreational : Changing facilities with showers 1.00 Recreational : Fitness Studio 1.04 Recreational : Fitness Suite/Gym 1.04 Recreational : Sports ground changing rooms Retail Warehouse Sales area - general 2.89 Small Shop Unit Sales area - general Stage (theatres and event buildings) Storage Area/Cupboard Teaching Areas Toilet Waiting Rooms Workshop 14

15 Conclusions iserv has demonstrated a method for producing benchmark ranges of performance at the level of individual HVAC components serving specific activities These benchmarks are used within iserv to benchmark real buildings and systems, and have helped produce significant energy savings The Power Demand and Energy Conservation benchmarks derived from iserv data will be published in Summer

16 Questions? Inspection of HVAC systems through continuous monitoring and benchmarking Contact details: The sole responsibility for the content of this presentation lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EACI nor the European Commission are responsible for any use that may be made of the information contained here.