Control Strategies Affected by Changes in IECC-2012

Transcription

1 Control Strategies Affected by Changes in IECC-2012 Oct 2012

2 Siemens Building Technologies, Inc. is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or constructed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. AIA/CES

3 Learning Objectives After attending the Control Strategies Affected by Changes in IECC-2012" seminar, the participant will: Learn about the history leading up to the current standard Identify how equipment changes effect the controls Prepare for changes in controls specifications and sequences Understand suggestions for reaching new efficiency goals Oct 2012 page 3

4 Agenda Codes and Standards Background Equipment Changes and Controls Controls for HVAC Non-HVAC Controls Best Practices Oct 2012 page 4

5 History of Commercial Building Energy Codes Year 90.1 Revision Year Energy Efficiency Description ,000 BTU/ft 2 /Year National Energy Conservation Policy Act (NECPA) Energy Policy Act mandates all states must review/consider adopting the national model energy standard (ASHRAE ) ,300 BTU/ft 2 /Year 1992 Energy Policy Act requires States energy codes to meet/ exceed ASHRAE by July 15, ,000 BTU/ft 2 /Year Energy Policy Act of 2005 mandated all states must review/ consider adopting national model energy standard (ASHRAE ) ,000 BTU/ft 2 /Year American Clean Energy & Security Act of 2009 (ACES) DOE adopts National Energy Code based on ASHRAE ,300 BTU/ft 2 /Year American Recovery & Reinvestment Act of 2009 (ARRA) Requires IECC as code based on ; 11% below ASHRAE ,000 BTU/ft 2 /Year IECC-2012 update; 30% energy savings over States adopt no later than December ,500 BTU/ft2/Year 50% energy savings below (Goal) Oct 2012 page 5

6 ASHRAE 90.1 Recent Milestones 1999 Major Revision 2001 Minor revisions 2004 Verbiage changed to Code language - SSPC 90.1 adopts continuous maintenance Addenda on the go ; compiled every 3 years Addenda adopted VAV Zone controls limit reheat and recool - Single Zone VAV DX requires fan modulation above 9 tons Exterior lighting densities defined and incentives for lighting controls Heat pump Pool heater require COP of Addenda adopted about mechanical Information is drawn from ASHRAE Journal 2008, Schwedler, Mick The Future of 90.1 Oct 2012 page 6

7 Building Codes ICC is largest standards management body for construction in US - Combined BOCA, ICBO, and SBCCI International Energy Conservation Code (IECC) for Commercial Buildings created in Similar to IECC 2006 adopts as reference energy standard Latest IECC update References ASHRAE Supplemental language above and beyond 90.1 Most states have adopted automatic update of codes based no update to IECC or 90.1 Information is drawn from the U.S. Department of Energy s (DOE) Building Energy Codes Program and the Building Codes Assistance Project (BCAP) Oct 2012 page 7

8 Design Standards LEED 2009 (v3) - EAp2 Min Energy Performance - EAc1 Optimize Energy Performance - Reference without addenda LEED lags in adoption - 3 years behind IECC years behind with addenda Customer Driven - ex. Federal Government - ex. University President s Commitment IECC-2009 coincides with LEED EA minimum: NC Code = EAp2 EB Code = EAp2 Oct 2012 page 8

9 States Adoption of Building Codes Source: US Dept of Energy Building Energy Codes Program Website Source: US Dept of Energy Building Energy Codes Program Website Oct 2012 page 9

10 States Adoption of Building Codes IECC-2012 design model is approximately 18% more efficient than LEED minimum: NC Code = EAc1 4 points Source: US Dept of Energy Building Energy Codes Program Website EB Code = EAc1 6 points Oct 2012 page 10

11 California Title 24 Comparison Source: Rethinking Percent Savings: The Problem with Percent Savings and the New Scale for a Zero Net-Energy Future, prepared by Architectural Energy Corporation and Southern California Edison; FIGURE 2 CURRENT ENERGY METRIC Oct 2012 page 11

12 Progress Toward Sustainability Oct 2012 page 12

13 IECC Energy Efficient Design of Commercial Buildings Target: New Buildings 2006 Edition, (baseline set by ) 2009 Edition, ( ) 18% more energy efficient than 2006 edition 2012 Edition, ( ) 30% more energy efficient than 2006 edition Over 100 Approved Addendums Controls mentioned 67 times ASHRAE , the Challenge 50% more energy efficient than 2006 edition. Oct 2012 page 13

14 SSPC 100 Energy Efficient Existing Buildings Target: Existing Buildings [Under Development] Purpose: Energy efficient exiting buildings Provide procedures and programs towards energy efficient operation, maintenance, management and monitoring; Increase energy efficiency of energy-using systems and components; and Upgrading thermal performance of the building envelope. Oct 2012 page 14/23

15 US Climates 9 Climate Zones + 3 moisture zones = 17 climates Oct 2012 page 15

16 Agenda Codes and Standards Background Equipment Changes and Controls Controls for HVAC Non-HVAC Controls Best Practices Oct 2012 page 16

17 Equipment Changes and Effects on Controls Design Standard Says Equipment Efficiency Ratings changed from SEER to IEER - Recognizes part load performance - Covers a variety of terminal units Heat pumps Fan Coils VRF Rooftops Effect on Controls -Decoupled cooling components - Packaged cooling terminal units VRF and HPs - More points to monitor - More smart terminal units = more integration and less single source controls - Less pure VAV box systems - AHUs driven by Vent loads not design cooling loads Part load efficiency means part load sensing + part load outputs which means smarter controls. Oct 2012 page 17

18 Equipment Changes and Effects on Controls Design Standard Says All AC equipment with water cooled condensers must have a control valve that can stop the flow when cooling is not needed (C ) Effect on Controls More Control Valves Coordinate pumps with 0% call for cooling Promotes variable pumping systems with controls Oct 2012 page 18

19 Equipment Changes and Effects on Controls Design Standard Says Added VRF Systems Effect on Controls - More options to move away from pure VAV systems Added Water-to-Water HPs - More options for using water source heat rejection Recognizes condenser heat recovery methods - More options for synergy between heating and cooling Machine efficiency requirement determined by heat rejection method -More options for engineers to reject heat Oct 2012 page 19

20 Equipment Changes and Effects on Controls Design Standard Says Fan speed reduction required on small packaged AHUs - Tons >9.2 at loads less than 50% - 2 speed or variable fan speed Effect on Controls More complex packaged units More smart rooftops integration to BAS is good practice Vent volume should be maintained If serving a DCV zone, then more control loops and variable vent Oct 2012 page 20

21 Equipment Changes and Effects on Controls Design Standard Says Fan speed reduction required on CHW AHUs - fan motor > 5 hp - 2 speed or variable fan speed Effect on Controls Fan speed controls Variable ventilation positions Compensation for building pressure balancing Discharge temperature sensors If DCV zones, then OAI monitoring required More controls points on smaller systems Was 15 hp in IECC-2006 ( ) Oct 2012 page 21

22 Equipment Changes and Effects on Controls Design Standard Says Zone 5a and 6a Energy Recovery Ventilation Requirements Climate Zone 3bc,4bc, 5b Table Exhaust Air Energy recovery Requirements % Outdoor Air at Full Design Airflow Rate 30-40% 40-50% 50-60% 60-70% 70-80% > 80% Design Supply Fan Airflow Rate (cfm) NR NR NR NR b,2b,5c NR NR b a-6a >0 7, >0 >0 >0 >0 Oct 2012 page 22

23 Equipment Changes and Effects on Controls Design More control points Coordinate with Economizer Energy Recovery Effect on Controls Bypass for economizer means motorized isolation dampers Exceptions for labs, warehouses, solar heat, distributed exhaust Oct 2012 page 23

24 Equipment Changes and Effects on Controls Design VFDs on unitary water pumps > 5 hp Standard Says VFDs on all other system water pumps > 10hp (Down from 50hp) Effect on Controls -VFDs on almost all pumps - More points to monitor - Sensor to control pump - More control loops - More communication points Oct 2012 page 24

25 Equipment Changes and Effects on Controls Design Standard Says Chiller Part Load Efficiency metric to meet (Addendum M) Effect on Controls - 80% of chiller operation spent at less than 50% load - Sequencing chiller more complex - Whole system optimization should take into account system loads, pump speeds, tower approach, etc. - Chiller efficiency taken before compressor VFD means less attractive to put VFD on compressor Oct 2012 page 25

26 Equipment Changes and Effects on Controls Design Standard Says Chiller Part Loads Part II Effect on Controls Water distribution improvements: Flatten system flow curve for better turn down Better matching of control valves to coils to raise coil T More modulating control valves to reduce spikes Temperature reset strategies to keep coils in sweet spots Flow modulation to keep T high More variable primary flow systems Oct 2012 page 26

27 Equipment Changes and Effects on Controls Design Data Center Additions Adds CRAC units to scope of standard (Addendum Aq) Data Center Exceptions Lists exceptions for economizers Adds efficiency requirements for computer rooms (Addendum Bu) Data Center modeling is not available in 90.1 New requirements when using water and air side economizers Alternative to modeling is power usage effectiveness (PUE) Significant additions to come in future additions to the standard. Oct 2012 page 27

28 Controls for HVAC Oct 2012 page 28

29 Controls for HVAC Water side Standard Says Requires service water booster pumps to be controls by VFDs Effect on Controls -Eliminates PRVs on domestic water - Adds VFDs, sensors, control loops - More points to monitor - More critical alarms Packaged racks of pumps with controls are common solution. Opportunity for integration to BAS for single source operation. Oct 2012 page 29

30 Controls for HVAC Water side Standard Says Isolation valves on systems with multiple chillers or boilers Reduces bypass mixing inefficiencies Improves coil efficiencies Reduces pumping energy Effect on Controls Isolation valves added to water loops Need to interlock to equipment Need safety to make sure equipment is not run with no flow Need safety to pumps to make sure not deadheaded Valve sizing more critical Pressure independent valves less attractive Steven McCloskey Oct 2012 page 30

31 Controls for HVAC Water side Standard Says Pump pressure optimization Effect on Controls Variable speed pumping over 10hp Pressure sensors to maintain pressure at extreme locations Poll valves to adjust pressure setpoint such that 1 valve is near 100% open Requires a BAS system Oct 2012 page 31

32 Controls for HVAC Water side Standard Says Temperature Control Reset above 300,000 BTU/h (C ) Effect on Controls Hot water systems traditional resets Effect on Controls Chiller systems look at zone or return loads Require BAS control Tight constraints Move slow Oct 2012 page 32

33 Controls for HVAC Air side Standard Says IECC-2012 is more strict than 90.1 > 33,000 BTU/h (3 tons) (C ) ( is > 54,000 BTU/h, 4.5 tons, 6.5.1) Effect on Controls May be needed for zone heat pumps bolt on strategy Must be sized to match max design supply airflow Must be sequenced with the mechanical cooling, not mixed air Water coil economizers can be substituted Exceptions including heat recovery and cooling efficiency increase (See Table on next slide) Oct 2012 page 33

34 Controls for HVAC Air side Standard Says Economizers Effect on Controls Exceptions including heat recovery and cooling efficiency increase (Table 6.3.2) Oct 2012 page 34

35 Controls for HVAC Air side Standard Says Motorized and Low Leakage Dampers at outdoor barriers > 2 story buildings > 300cfm ( ) Effect on Controls Must operate with ventilation schedules Includes stairways and shafts (fail open) 4 cfm/ft 2 at 1.0 in.wg Exception for 1 and 2 story buildings and less than 300 cfm Oct 2012 page 35

36 Controls for HVAC Air side Standard Says VAV required on more special applications: Hospital applications Labs Requires more heat recovery Removed blanket exception for labs and pressurization Effects on Controls Significantly increases complexity of lab controls Requires VAV hoods Requires pressurization controls Requires VAV MUA units Many conditions and exceptions to requirements. Many details covered by other standards. Oct 2012 page 36

37 Controls for HVAC Air side Standard Says Supply Air Temperature Reset Multizone shall automatically raise the supply air temperature when the spaces served are not at peak loads Effect on Controls Infers BAS that can monitor zone statuses as input to the setpoint control Goal is to decrease cooling load, reduce reheat, increase economizer usage Tight constraints - setpoints between 50 and 60F Suspended for dehumidify control Oct 2012 page 37

38 Controls for HVAC Air side Standard Says Demand Control Ventilation IECC more strict at 25 people per 1000 ft 2 (90.1 above 40 people per 1000 ft 2 ) Ventilation optimization required on Variable Volume systems Exemptions: Heat Recovery, no DDC, OAI<1,200 cfm EA RA CO 2 space OA SA Oct 2012 page 38

39 Controls for HVAC Air side Single Zone AHU Demand Control can be at AHU Population count Ventilation Reset Formulas reset OAI cfm CO2 can reset directly If DCV is chosen EA RA space CO 2 OA SA Oct 2012 page 39

40 Controls for HVAC Air side If DCV is chosen Example of single zone OA Intake reset based on CO2 Oct 2012 page 40

41 Controls for HVAC Air side Zone Level Demand Control Population count Box position reset CO2 can be used with formulas If DCV is chosen S A space CO 2 CO 2 space Oct 2012 page 41

42 Controls for HVAC Air side Multi Zone Mixed Air VAV DCV at box Population count all zones Ventilation Optimization based on population count Ventilation reset because of VAV fan speed Formulas to take credit for some zones over-ventilated If DCV is chosen Oct 2012 page 42

43 Controls for HVAC Air side Dedicated Outdoor Air -Simple Constant flow to all zones 2 position hi-lo ventilation for high occupancy zones If DCV is chosen Oct 2012 page 43

44 Controls for HVAC Air side Dedicated Outdoor Air - Advanced Population count from all zones Pressure independent boxes serving all zones If DCV is chosen If terminal units are variable fan speed, then PI boxes are needed Oct 2012 page 44

45 Controls for HVAC Air side No simultaneous heating and cooling 20F max reheat above zone setpoint Reduce VAV minimums as low as possible SA Reset will help DCV can reduce minimums in some spaces DDC boxes can control to 10:1 turndown compared to 5:1 Encourages separate htg source Standard Says Effect on Controls Dual max DDC controls is new standard Oct 2012 page 45

46 Controls for HVAC Air side Standard Says Requires 2-stage ventilation for enclosed garages Effect on Controls CO sensors and control panels 2-speed or VFD fans for 50% reduction Suggestion: Adding to BAS for monitoring is cheap adder Oct 2012 page 46

47 ASHRAE Lighting Changes Revised/Interior LPDs (efficiency, geometry) Exterior LPD requirements expansion Detailed daylighting control and skylight requirements Occupancy Sensor Control (more spaces, vacancy) Exterior Lighting Control (after-hours requirements) Parking Garage Lighting Control (daylighting & afterhours) Emergency (night light) shut-off and Stairwell control Lighting Controls Control incentives for advanced controls Guest bathroom lighting control Receptacle shut-off control (50% auto-off) Functional Testing (Commissioning) Oct 2012 page 47

48 ASHRAE Receptacle Shutoff (50% Auto-off) Requires 50% of receptacles (wall plugs) in a space to have automatic shutoff control. Applies to 125 volt (15-20 amp) receptacles in Private Offices, Open Offices and Computer Classrooms. Requires automatic control using Time of Day Scheduling Occupancy Sensor or, Other automatic control based on occupancy Oct 2012 page 48

49 BAC MS/T RS4 How Do We Get to Goal? Interoperability Steven McCloskey Oct 2012 page 49

50 How Do We Get to Goal? ASHRAE Advanced Energy Design Guides Small Office Buildings building with total floor area of 20,000 ft 2 Daylight harvesting with Interior Lighting Controls Packaged rooftop or split system heat pumps serving each zone. Ventilation provided by Dedicated Outside Air System (DOAS). DOAS system with Energy Recovery Ventilation (ERV) Medium Office Buildings Three-story building with total floor area of 53,600 ft 2 Daylight harvesting and occupancy based controls. DOAS with Heat Recovery Radiant Systems (Heating & Cooling) Light Commercial Building Market Fastest growing building market segment Oct 2012 page 50

51 How Do We Get To Goal? Just Do It Migrate to more energy efficient HVAC and Lighting tech Designing for Part Load Efficiency Synergies Heat Reclaim Coordinating lights with HVAC Plant equipment reset from zone control Load Matching Systems New Technologies Mixed-Mode Ventilation Automated Operable Windows Blind Controls Building Façades Load Matching Systems Renewable Energy Oct 2012 page 51

52 References and More Information Sources 1. US Dept of Energy Building Energy Codes Program Website h ttp:// adoption/states 2. International Code Council 3. Illinois Dept of Commerce Energy_Recycling/IECC.htm IECC Seminars WILBUR WRIGHT COLLEGE Chicago, IL March 22, 2013 HARPER COLLEGE (WOJCIK CONF. ) Palatine, IL March 27, 2013 URBANA CIVIC CENTER Urbana, IL April 5, 2013 SOUTH SUBURBAN COLLEGE Oak Forest, IL April 9, 2013 WAUBONSEE COMMUNITY COLLEGE Sugar Grove, IL April 16, 2013 CHICAGO DEPT. OF BUILDINGS DePaul Center Loop Campus May 15, 2013 To Register, Click on a Location! Oct 2012 page 52

53 Best Practices 1. For every decision, ask What is long term impact on energy. 2. Embrace resetting strategies like population counting and setpoint optimizations 3. Automate system reactions to leave operators to handle only exceptions or problems. 4. Use Energy Management Software for info use Automation for control. Oct 2012 page 53

54 Thank you Questions Oct 2012 page 54