What s on the Horizon for HVAC in Title ? Mark Hydeman, PE, Principal Taylor Engineering, LLC

Transcription

1 What s on the Horizon for HVAC in Title ? Mark Hydeman, PE, Principal Taylor Engineering, LLC WHAT S WHAT S ON THE ON THE HORIZON HORIZON FOR FOR HVAC HVAC IN TITLE IN TITLE ? ? MAY 2011 SLIDE 1

2 Agenda Overview Economizers Labs (and ERV) ECMs Cooling Towers Chillers Single Zone VAV and Integrated Economizers Reheat WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 2

3 Handouts You can get a copy of the handouts from a more detailed all day presentation of this topic in PDF format as follows: Type the following link into your web browser: Click on the link for the Title 24 HVAC 2013 program to download the Acrobat file of the presentation. WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 3

4 Energy Codes and Their Kin Laws are like sausages the less you know about how they are made the more respect you have for them. Otto von Bismarck WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 4

5 New Building Regulations and Incentives Overview Incentives pull the innovators Regulations and codes push the laggards Today s incentives will become future regulations Whoohoo, I m code certified! PIER Research Utility Incentives Product Rebates LEED NC: Platinum Gold Silver Rated AEDG Guides Green Building Code & & T24 WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 5

6 What s Really Effective in Reducing Energy? LEED New Building Institute (NBI) survey of LEED buildings. See: er/ _newsletter.htm Measured energy use per sf Energy Regulations and Public Goods Programs California s Energy use per capita compared to the rest of the US. See: tions/cec /cec pdf WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 6

7 Non-Residential HVAC Measures We cannot cover all of these today! Data Centers (TE) Labs (TE) Variable Speed Single Zone (TE) Kitchen Ventilation (TE) Chiller Efficiency (TE) Garage Ventilation (TE) Small ECM Motors (TE) Cooling Towers (TE) Reduce Reheat (TE/ES) Heat Recovery for High ACH (TE) Hot Water Temperature Reset (TE) HVAC Controls and Economizing (PECI) OA Ventilation (CTG) HVAC Efficiency and Baseline (HMG) Radiant Cooling (HMG) Water Heater Standby Loss (HMG) Process Boilers (PECI) Air Compressors (ES) Acceptance Testing (PECI/ES) Upgradeable Setback Thermostats for Demand Response (HMG) Supermarket Refrigeration (HMG/VaCom) Refrigerated Warehouses (PECI/VaCom) WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 7

8 Resources CASE Initiatives: CEC Website: aking/ WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 8

9 Schedule: Key Dates 2010 CEC Foundation Work o Updated Weather files: completed June/July 2010 o Updated TDV analysis: ready for CASE team end of Aug 2010 CASE Work o conduct market research, collect cost data: thru 2 nd Qtr o conduct analysis based on 2013 TDV: starting Sept 2010 o present results at stakeholder meetings: Sept. Nov Jan 2011 IOUs finalize code change proposals for submittal to CEC Feb 2011 Open Rulemaking, develop 45-day language June 15, 2011 Adoption date Jan. 1, 2013 Implementation date These measures are cost effective. You have 2-3 years left to get rebates for using them! WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 9

10 Where will these end up? 2013 T-24 Base Code (Title 24, Part 6) 2013 Reach Standard (Title 24, Part 11) Green Building Standard (i.e. CalGreen) Voluntary standards that local governments can adopt Some Mandatory components Future Codes 2016 T-24 Future Reach Codes WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 10

11 New Foundations New Weather Files New TDVs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 11

12 Economizers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 12

13 Air Economizer Control Economizers MINIMUM OA DAMPER ECONOMIZER OA DAMPER SUPPLY FAN OUTDOOR AIR HIGH LIMIT SWITCH RETURN AIR RA DAMPER CHW VALVE SUPPLY AIR TEMP CONTROLLER SUPPLY AIR TEMP SENSOR 100% OPEN RA DAMPER CHW VALVE 0% OPEN OA DAMPER SUPPLY AIR TEMP CONTROL LOOP WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 13

14 Economizer Overview Economizers High limit switches Acceptance tests Compressor unloading (multistage or VS) WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 14

15 Results Economizers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 15

16 Recommendations Economizers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 16

17 Reference Economizer High-Limit Controls and Why Enthalpy Economizers Don t Work By Steve Taylor and Hwakong Cheng ASHRAE Journal November 2010 Available at WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 17

18 Laboratories WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 18

19 Overview Labs Extension of Scope for Processes like labs and Data Centers VAV Lab Proposal Heat Recovery Proposal WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 19

20 Process Scope Labs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 20

21 Process Scope Labs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 21

22 Process Scope Labs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 22

23 VAV Requirement Labs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 23

24 Run Around Loop (Reach Code) Labs WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 24

25 Lab Issues Labs CalOSHA and ARB want us to include reference to Title 8 Standards (design and operation). CalOSHA and ARB are opposed to the run-around coils as the coils are in the exhaust air stream. WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 25

26 Small Motors WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 26

27 Small motors Currently ECM motors are required on only series-style fan-powered boxes Will investigate for all small exhaust fans, supply fans and possibly parallel style VAV boxes Savings from Higher motor efficiencies Ability to balance in field Variable flow controls Likely to be in the reach code Issue with minimum power factor WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 27

28 Cooling Towers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 28

29 Cooling Towers Towers Cooling tower efficiencies unchanged since T ( ) Existing efficiencies were designed to cut out bottom ~5% of the products. There was no analysis used to determine the efficiency levels Cooling towers not federally pre-empted but T24 has always followed 90.1 VSDs required since 2001 for 7.5hp (144(h)2) Title added Minimum flow 33% (144(h)3), and Restriction on centrifugal cooling towers (144(h)4) for towers with rated capacity of > 900 gpm (~300 tons) at 95/85/75 (all cells) WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 29

30 Cooling Towers Towers Modeling indicates that we could require 80 gpm/hp minimum efficiencies. Pushback from manufactures Concerns about shift to air-cooled DX and other systems WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 30

31 Cooling Tower Water Measures Towers Starting in 2013 the CEC can include water conservation measures in Title 24, Part 6 (aka Title 24) Require TDS controller, and One of the following: Minimum cycles of concentration X% use of reclaimed water Y% reuse of blowdown for irrigation or grey water systems WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 31

32 Chillers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 32

33 Overview Chillers Chiller efficiency unchanged since 2001 Chillers not federally pre-empted but T24 has always followed (2007 Addenda M, BL & BT) Higher efficiencies and two paths for compliance (Path A & Path B) Deleted category of air-cooled chiller without condenser Consolidated positive displacement chillers (screw, scroll & reciprocating) Extended range of non-standard k equation WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 33

34 Overview Chillers Proposal for Title Mandatory o Adopt 90.1 Chiller Efficiencies Paths A & B o Delete air-cooled without condenser o Consolidate positive displacement chillers (screw, scroll & reciprocating) o Adopt new non-standard k equation o Delete non-standard tables 112-H, I, J, K, L, M Prescriptive Path o Require path B based on LCC o Provide exceptions as noted in following slides Performance Path o Budget system to follow Prescriptive requirements WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 34

35 Proposed Code Change Mandatory New Table 112D Chillers ASHRAE 2 Chiller Efficiency WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 35

36 Proposed Code Change Mandatory New Table 112D Chillers ASHRAE 2 Chiller Efficiency WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 36

37 Single Zone VAV and Integrated Economizers WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 37

38 Current Code Requirements SZ VAV Title : Effective 1/1/2012, DX and chilled water (CHW) units 10 tons shall be VAV o (have VFD or 2 speed supply fans to reduce speed below 2/3 of full speed at low load) ASHRAE : Effective 1/1/2010, CHW units 5 hp shall be VAV Effective 1/1/2012, DX units 10 tons shall be VAV WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 38

39 Code Change Proposal Fan Control SZ VAV Fan Control. Each unitary air conditioner and air-handling unit with mechanical cooling capacity listed in Table X shall be designed to vary the airflow rate as a function of actual load and shall have controls and/or devices (such as two-speed or variable speed control) that will result in fan motor demand of no more than 50 percent of design wattage at 66 percent of design fan speed. Table X Effective Date for 2-Speed or Variable Speed Fan Control. mechanical cooling capacity at ARI conditions Effective Date Unitary air conditioners >=110,000 Btu/hr January 1, 2012 Unitary air conditioners >=65,000 Btu/hr and <110,000 January 1, 2015 Btu/hr Chilled water fan systems having a fan motor January 1, 2012 horsepower 1/4 hp and larger WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 39

40 Code Change Proposal Integrated Economizers Mechanical cooling shall be capable of staging or modulating capacity in increments of no more than 50% of total cooling capacity for unitary systems less than 65,000 Btu/hr at ARI conditions and no more than 20% of total cooling capacity for all other systems. Controls shall not false load the mechanical cooling system by limiting or disabling the economizer or any other means, such as hot gas bypass, except at the lowest stage of cooling capacity. WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 40

41 Typical Practice SZ VAV Fan Control: Typical practice for single zone (SZ) units (CHW and DX) is constant volume We estimate less than 5% of SZ DX units are VAV We estimate less than 10% of SZ CHW units are VAV Integrated Economizers: Packaged units do not fully capture economizer savings because minimum compressor runtimes cause the economizers dampers to cycle WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 41

42 Multiple Zone AHU Economizer Trends SZ VAV WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 42

43 Multiple Zone AHU Economizer Trends SZ VAV WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 43

44 Potential Code Change Rationale SZ VAV All CHW SZ Units shall be VAV VFD and ECM motor costs have come down dramatically in recent years We expect the fan and cooling savings to pay for the VFD/ECM for all sizes Effective 1/1/2015 DX units 6 tons shall be VAV The effective date and size will be negotiated with AC manufacturers Units 5 tons and below are preempted by NAECA Ensure that economizers are integrated on these units (requires multiple stages of compression or unloading) WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 44

45 New Products in Recent Years SZ VAV DX 3 ton VAV SZ packaged units with variable capacity compressors and variable speed fans 2 ton digital scroll compressors 1 ton mini-splits with variable speed compressors Multizone variable refrigerant flow (VRF) systems down to 4 tons ECM motors standard on some small packaged units Digital scroll or turbocor compressors optional on large VAV packaged units CHW ECM motors standard option on many fan coils and unit ventilators Fractional horsepower VFDs are cheap and easy to add to fan coils WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 45

46 Reduced Reheat WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 46

47 Current Title 24 Reheat Exceptions Reheat For non-ddc (direct digital control) systems Reduces min VAV airflow to 30% For DDC systems Single Max. Reduces reheat/recool to 20% in deadband Allows reheat/recool to 50% at peak heating Dual Max. In both cases, the minimum can be increased to meet the zone ventilation requirements WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 47

48 Proposed T Reheat Language Reheat EXCEPTION 1 to Section 144(d): Zones served by variable air-volume systems that are designed and controlled to reduce, to a minimum, the volume of reheated, re-cooled, or mixed air supply are allowed only if the controls meet the following requirements: A. For each zone with direct digital controls (DDC): 1. The volume of primary air that is reheated, re-cooled, or mixed air supply shall not exceed the larger of: a. 50 percent of the peak primary airflow, or b. The design zone outdoor airflow rate per Section The primary airflow in the deadband shall not exceed the larger of: a. 20 percent of the peak primary airflow; or b. The design zone outdoor airflow rate per Section Airflow between deadband and full heating or full cooling must be modulated 3. The first stage of heating consists of modulating the zone supply air temperature setpoint up to a maximum setpoint while the airflow is maintained at the deadband flow rate. 4. The second stage of heating consists of modulating the airflow rate from the deadband flow rate up to the heating maximum flow rate. WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 48

49 30% Single Max Only Allowed for Pneumatics Maximum Airflow Setpoint Reheat Valve Position Airflow Setpoint 30%, or vent. (shaded area = reheat) Heating Loop Dead Band Cooling Loop WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 49

50 Dual Max / Temperature First Most Efficient Maximum Supply Air Max Cooling Airflow Setpoint Temperature [Summarize what we believe typical practice is. Ask for feedback on whether Supply Air Temperature this is Setpoint correct.] 50% or vent. Airflow Setpoint 20%, or vent. (shaded area = reheat) Heating Loop Dead Band Cooling Loop WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 50

51 Dual Max/Constant Volume Heat NOT ALLOWED! Reheat Valve Position Once in heating mode, the cooling load must exceed 50% of design cooling load to unstick the zone from heating mode Maximum Airflow Setpoint 50% Airflow Setpoint 20% (shaded area = reheat) Heating Loop Dead Band Cooling Loop WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 51

52 Dual Max / Simultaneous - To be prohibited in T % Max Cooling Airflow Setpoint [Summarize what we believe typical practice is. Ask for feedback on whether this is correct.] 50% or vent. Reheat Valve Airflow Setpoint 20%, or vent. (shaded area = reheat) Heating Loop Dead Band Cooling Loop WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 52

53 Questions WHAT S ON THE HORIZON FOR HVAC IN TITLE ? SLIDE 53