US DOE 90.1 2010 HVAC & SWH-presentations_中英對照

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US DOE 90.1 2010 HVAC & SWH-presentations_中英對照

  1. 1. BUILDING ENERGY CODES UNIVERSITYANSI/ASHRAE/IESStandard 90.1-2010 HVAC Erik chiang 1April 2011 – PNNL-SA-80143 www.energycodes.gov/BECU
  2. 2. HVAC Compliance Building System Compliance Options Prescriptive Envelope Option Mandatory HVAC Provisions Trade Off Energy Code (required for most Option Compliance SWH compliance options) Energy Cost Power Budget Lighting Simplified Other 2 www.energycodes.gov/BECU
  3. 3. Section 6 – 6.1.1HVAC Scope 9 New Buildings 9 Additions to Existing Buildings 9 Alterations in Existing Buildings 3 www.energycodes.gov/BECU
  4. 4. Section 6 – 6.1.1.3HVAC Alterations Scope 9 Equipment – New equipment shall meet the minimum efficiency requirements – 9 Cooling systems – New cooling systems installed to serve previously uncooled spaces shall comply with this section – Alterations to existing cooling systems shall not decrease economizer capacity (unless economizer tradeoff is used) ( ) 9 Ductwork – New and replacement ductwork shall comply with applicable requirements – 9 Piping – New and replacement piping shall comply with applicable requirements 4 www.energycodes.gov/BECU
  5. 5. Section 6 – 6.1.1.3HVAC Alterations Alterations to the building HVAC system shall comply with the requirements of Section 6 6 9 Exceptions that are allowed: , – Equipment being modified or repaired (not replaced) ( ) • provided such modifications will not result in an increase in the annual energy consumption – Equipment being replaced or altered which requires extensive revisions to other systems and such replaced or altered equipment is a like-for-like replacement , – Refrigerant change of existing equipment – Relocation of existing equipment – Ducts and pipes where there is insufficient space or access to meet these requirements 5 www.energycodes.gov/BECU
  6. 6. Section 6 – 6.2HVAC Compliance Paths 9 You have to follow Sections – 6.1 General, – 6.7 Submittals, and – 6.8 Minimum Equipment Efficiency 9 And then you can follow either – Section 6.3 Simplified Approach OR 6.3 , – Sections 6.4 Mandatory Provisions and 6.5 Prescriptive Path 6.4 6.5 9 Alternatively, you can follow Section 11 (ECB), in which case Section 6.4 is mandatory , 11 ( ), 6.4 6 www.energycodes.gov/BECU
  7. 7. Section 6 – 6.3Simplified Approach Option The simplified approach is an optional path for compliance when the following are met: , 9 Buildings with 1 or 2 stories 1 2 9 Buildings with gross floor area < 25,000 ft2 < 25,000 ft2 9 System serving single HVAC zone 9 Unitary packaged or split air conditioners (air-cooled or evaporatily cooled) ( ) 7 www.energycodes.gov/BECU
  8. 8. Section 6 – 6.3Simplified Approach Criteria a. Single HVAC zone b. Single zone VAV controls (6.4.3.10) VAV c. Cooling equipment efficiency (6.8.1) d. Air economizers (6.5.1) e. Heating equipment efficiency (6.8.1) f. Exhaust air energy recovery (6.5.6.1) g. Dual set point thermostat or manual changeover h. Heat pump auxiliary heat control i. No reheat or simultaneous cooling and heating for humidity control j. Off-hour shutoff and temperature setback/setup setback/setup k. Piping insulation (Tables 6.8.3A and 6.8.3B) l. Ductwork insulation and sealing (6.4.4.2.1) m. Air balancing of ducted system n. Outdoor air intake and exhaust systems (6.4.3.4) o. Zone thermostatic controls to prevent simultaneous heating and cooling p. Optimum start controls q. Demand control ventilation (6.4.3.9) 8 www.energycodes.gov/BECU
  9. 9. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls9 Supply fans controlled by two-speed motors or variable-speed drives – Air-handling and fan coil units with chilled-water cooling coils – Supply fans with motors • 5 hp >=5hp9 At cooling demands ” 50%, supply fan controls able to reduce airflow to no greater than the LARGER of <=50%, – ½ of the full fan speed OR 1/2 , – volume of outdoor air required to meet Standard 62.1 On and after January 1, 2012 62.1 2012.1.1 , 9 www.energycodes.gov/BECU
  10. 10. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls9 Supply fans controlled by two-speed motors or variable speed drives – all AC equipment and air-handling units with direct expansion cooling and cooling capacity at AHRI conditions • 110,000 Btu/h serving single zones AHRI >=110,000Btu/h9 At control demands – 2/3 of the full fan speed OR 2/3 – volume of outdoor air required to meet Standard 62.1 62.1 10 www.energycodes.gov/BECU
  11. 11. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls (cont’d) 11 www.energycodes.gov/BECU
  12. 12. Section 6 – 6.8.1A (6.3.2c)Equipment Efficiency Reference Tables 6.8.1A, 6.81B and 6.8.1.D in 90.1-2010 90.1-2010 , 6.8.1A, 6.8.1B, 6.8.1D 12 www.energycodes.gov/BECU
  13. 13. Section 6 – 6.3.2Economizers The system shall have an economizer, unless the economizer Trade-off Option is used , 9 Limited to unitary systems 9 Requires higher minimum cooling efficiency (EER) (EER) 9 Trade-off EER by EER – System size – Climate zone 13 www.energycodes.gov/BECU
  14. 14. Section 6 – 6.3.2Economizers Reference Table 6.3.2 on page 40 in 90.1-2010 14 www.energycodes.gov/BECU
  15. 15. Section 6 – 6.5.1 (6.3.2d)Economizers (cont’d) 9 Climate and size dependent (Tables 6.5.1A and B) ( 6.5.1A B) 9 There are LOTS of exception 9 Can use air economizers – 100% of design supply air 100% – Sequenced with mechanical cooling equipment – High limit shutoff – Dampers 15 www.energycodes.gov/BECU
  16. 16. Section 6 – 6.5.1 (6.3.2d)Economizer Exceptions Exceptions 9 Systems with gas phase air cleaning per Standard 62.1 62.1 9 Where >75% of the air must be humidified >35 Fdp 75% >35 Fdp 9 Systems with condenser heat recovery per 6.5.6.2.2a or 6.5.6.2.2b 6.5.6.2.2a 6.5.6.2.2b 9 Residential systems <5X limits in Table 6.5.1A < 6.5.1A 5 9 Systems with a balance point <=60 F <= 60 F 9 Systems expected to operate < 20hrs/wk 20hr 9 Systems serving zones with refrigerated casework 16 www.energycodes.gov/BECU
  17. 17. Section 6 – 6.5.1 (6.3.2d)Economizer Exceptions (cont’d) Exceptions 9 Where comfort cooling efficiency meets or exceeds Table 6.3.2 6.3.2 9 Systems serving computer rooms under certain conditions , 17 www.energycodes.gov/BECU
  18. 18. Section 6 – 6.3Simplified Approach Option (cont’d) 9 Manual changeover or dual set-point thermostat 9 Heat pump supplementary control 9 No reheat or simultaneous heating and cooling for humidity control 9 Time clocks (except hotel/motel guest rooms and systems requiring continuous operation) ( / ) 18 www.energycodes.gov/BECU
  19. 19. Section 6 – 6.3Simplified Approach Option (cont’d) 9 Balancing of ducted systems 9 Outdoor air intake and exhaust systems 9 Interlocked thermostats for separate heating and cooling 9 System > 10,000 cfm: > 10,000 cfm – optimum start controls – 9 Demand control ventilation 19 www.energycodes.gov/BECU
  20. 20. Section 6 – 6.3Simplified Approach Option (cont’d) Piping and ductwork/plenum insulated / 20 www.energycodes.gov/BECU
  21. 21. Section 6 – 6.8.2BDuct Insulation Reference Tables 6.8.2A and B on page 68 in 90.1-2010 21 www.energycodes.gov/BECU
  22. 22. Section 6 – 6.4.4.1.3 (6.3.2k)Piping Insulation Tables 6.8.3A and 6.8.3B Exceptions 9 Factory-installed 9 Piping conveying fluids – design operating temperature range between 60 F-105 F, inclusive 60 F-105 F , – that haven’t been heated or cooled through the use of fossil fuels or electricity or where heat gain or heat loss will not increase energy usage , 9 Hot water piping between shut off valve and coil, not > 4 ft in length, when located in conditioned spaces , 4ft 9 Piping ” 1 in. <= 1 in. – No insulation required for strainers, control values, and balancing values , , 22 www.energycodes.gov/BECU
  23. 23. Section 6 – 6.8.3Piping Insulation Reference Tables 6.8.3A and B on page 69 in 90.1-2010 23 www.energycodes.gov/BECU
  24. 24. Section 6 – 6.5.6.1 (6.3.2f)Exhaust Air Energy Recovery Required if: 9 Supply air capacity • value listed in Table 6.5.6.1 >= 6.5.6.1 – Values are based on climate zone and % of outdoor air flow rate at design conditions Recovery system effectiveness • 50% >= 50% 24 www.energycodes.gov/BECU
  25. 25. Section 6 – 6.5.6.1 (6.3.2f)Exhaust Air Energy Recovery Exceptions 9 Lab systems meeting 6.5.7.2 6.5.7.2 9 Systems serving uncooled spaces that are heated to < 60 F < 60 F 9 Systems exhausting toxic, flammable, paint or corrosive fumes or dust , , 9 Commercial kitchen hoods used for collecting grease or smoke 9 Where > 60% of outdoor heating energy is provided from site- recovered or site solar energy > 60%, 9 Heating energy recovery in climate zones 1 and 2 1 2 9 Cooling energy recovery in climate zones 3c, 4c, 5b, 5c, 6b, 7, and 8 3c, 4c, 5b, 5c, 6b, 7 8 25 www.energycodes.gov/BECU
  26. 26. Section 6 – 6.5.6.1 (6.3.2f)Exhaust Air Energy Recovery Exceptions 9 Where largest exhaust source is < 75% of the design outdoor airflow < 75% 9 Systems requiring dehumidification that employ energy recovery in series with the cooling coil , 9 Systems operating < 20 hrs/week at outdoor air % in Table 6.5.6.1 6.5.6.1 , 20hr, 26 www.energycodes.gov/BECU
  27. 27. Section 6 – 6.8.2B (6.3.2l)Duct & Plenum Insulation Reference Table 6.8.2B on page 68 in 90.1-2010 27 www.energycodes.gov/BECU
  28. 28. Section 6 – 6.4.3.9 (6.3.2q)Demand Control VentilationDCV must be provided for each zone with a area > 500 ft² andthe design occupancy > 40 people/1000 ft² where the HVACsystem has: >500 ft² >40 /1000 ft² , , 9 An air-side economizer, 9 Automatic modulating control of the OSA dampers, or , 9 A design outdoor airflow > 3,000 cfm > 3000 cfm Demand control ventilation (DCV): a ventilation system capability that provides for the automatic reduction of outdoor air intake below design rates when the actual occupancy of spaces served by the system is less than design occupancy. 28 www.energycodes.gov/BECU
  29. 29. HVAC Compliance Building System Compliance Options Prescriptive Envelope Option Mandatory HVAC Provisions Trade Off Energy Code (required for most Option Compliance SWH compliance options) Energy Cost Power Budget Lighting Simplified Other 29 www.energycodes.gov/BECU
  30. 30. Section 6 – 6.4HVAC Mandatory Provisions 9 Minimum Equipment Efficiency (Section 6.4.1) 9 Calculations (Section 6.4.2) 9 Controls (Section 6.4.3) 9 HVAC System Construction and Insulation (Section 6.4.4) 30 www.energycodes.gov/BECU
  31. 31. Section 6 – 6.4.1.1Minimum Equipment Efficiency HVAC Equipment Covered 9 Air conditioners and condensing units 9 Heat pumps (air, water, and ground source) ( , ) 9 Water-chilling packages (chillers) 9 Packaged terminal and room air conditioners and heat pumps 9 Furnaces, duct furnaces and unit heaters , 9 Boilers 9 Heat rejection equipment (cooling towers) ( ) 31 www.energycodes.gov/BECU
  32. 32. Section 6 – 6.4.1.1Minimum Equipment Efficiency (cont’d) HVAC Equipment Covered 9 Heat transfer equipment (heat exchangers) ( ) 9 Variable refrigerant flow (VRF) air conditioners 9 VRF air-to-air and applied heat pumps 9 Air conditioners serving computer rooms 32 www.energycodes.gov/BECU
  33. 33. Section 6 – 6.4.1.4Verification of Equipment Efficiencies Equipment efficiency information from manufacturers verified as follows , 9 EPACT equipment – to comply with DOE certification requirements (EPACT) – (DOE) 9 If certification program exists for covered product and includes provisions for verification and challenge of equipment efficiency ratings, product listed in program OR , , , 9 If product not listed in program, ratings verified by an independent laboratory test report OR , , 33 www.energycodes.gov/BECU
  34. 34. Section 6 – 6.4.1.4Verification of Equipment Efficiencies (cont’d) 9 If no certification program exists, equipment efficiency ratings supported by data furnished by manufacturer OR , , 9 Where components from different manufacturers are used, system designer specifies components whose combined efficiency meets Section 6.4.1 , 6.4.1 9 Requirements for plate type liquid-to-liquid heat exchangers listed in Table 6.8.1H - , 6.8.1H 34 www.energycodes.gov/BECU
  35. 35. Section 6 – 6.4.1.5Labeling Mechanical equipment (6.4.1.5.1) – equipment not covered by NAECA to have a permanent label stating equipment complies with 90.1 (6.4.1.5.1) – NAECA 90.1 ( NAECA ) 35 www.energycodes.gov/BECU
  36. 36. Section 6 – 6.4.1.5Labeling Packaged terminal air conditioners (6.4.1.5.2) – packaged terminal air conditioners and heat pumps with sleeve sizes < 16 in. high and 42 in. wide with a cross-sectional area < 670 in2 to be factory labeled as follows: (6.4.1.5.2) – 16 42 670 , : 9 Manufactured for nonstandard size applications only: not to be installed in new construction projects : 36 www.energycodes.gov/BECU
  37. 37. Section 6 – 6.4.2.1Load Calculations Must calculate heating and cooling system design loads Must determine calculations with ANSI/ASHRAE/ACCA Standard 183-2007 ASHRAE Std. 183 37 www.energycodes.gov/BECU
  38. 38. Section 6 – 6.4.2.2Pump Head • When sizing pumps, head to be determined in accordance with generally accepted engineering standards/handbooks • Method must be approved by the authority having jurisdiction • Must calculate the pressure drop through each device and pipe segment in the critical circuit at design conditions • , 38 www.energycodes.gov/BECU
  39. 39. Section 6 – 6.4.3.1Controls – Zone Thermostatic & Dead Band Required for each zone 9 Perimeter can be treated differently Dead band controls 9 Thermostats must have at least a 5 F dead band 5F 9 Exceptions – Thermostats that require manual changeover between heating and cooling modes – Special occupancy or applications where wide temperature ranges aren’t acceptable (e.g., retirement homes) and approved by adopting authority , ( ; ) 39 www.energycodes.gov/BECU
  40. 40. Section 6 – 6.4.3.2Controls – Setpoint Overlap Restriction If limit switches, mechanical stops, or software programming for DDC systems are used , , DDC 9 means will be provided to prevent the heating setpoint from exceeding the cooling setpoint minus any applicable proportional band 40 www.energycodes.gov/BECU
  41. 41. Section 6 – 6.4.3.3Controls – Off-Hour Temperature Control off-hour requirements 9 Automatic shutdown 9 Setback controls 9 Optimum start 9 Zone isolation 9 Exceptions, HVAC systems , – with heating/cooling capacity < 15,000 Btu/h – / < 15,000 Btu/h – intended to operate continuously – 41 www.energycodes.gov/BECU
  42. 42. Section 6 – 6.4.3.3.1Controls - Automatic Shutdown Automatic 7-day/week time clock with 10-hour battery backup 10 9 Exception: 2-day/week thermostat for residential applications : , Each control to have 9 Occupant sensor, OR , 9 Manually-operated timer with maximum two hour duration, OR , , 9 Security system interlock Exception 9 Residential occupancies allowed to operate with only 2 different time schedules/wk 42 www.energycodes.gov/BECU
  43. 43. Section 6 – 6.4.3.3.2Controls - Setback Climate Zones 2-8 9 Lower heating setpoint to 55ºF or less 55ºF Climate Zones 1b, 2b, 3b (hot/dry) 9 Automatically restart, temporarily operate , – Raise cooling setpoint to 90ºF or higher OR 90ºF – Prevent high space humidity levels 43 www.energycodes.gov/BECU
  44. 44. Section 6 – 6.4.3.3.3Controls - Optimum Start Individual heating and cooling air distribution systems with , 9 Total design supply air capacity > 10,000 cfm > 10,000 cfm 9 Served by one or more supply fans Control algorithm to at least be a function of 9 Difference between space temperature and occupied setpoint and amount of time prior to scheduled occupancy , 44 www.energycodes.gov/BECU
  45. 45. Section 6 – 6.4.3.3.4Controls - Zone Isolation Applies to 9 Each floor in a multistory building 9 Maximum 25,000 ft2 zone on one floor 25,000ft2 Requirements 9 Isolation devices to shut off outdoor and exhaust airflow when > 5,000 cfm >5,000cfm , 9 Central systems shall be capable of stable operation with one isolation zone 9 Capable of separate time schedules for each isolation zone Figure 6-E Isolation Methods for a Central VAV System (User’s Manual – 90.1.-2007) 45 www.energycodes.gov/BECU
  46. 46. Section 6 – 6.4.3.4Controls – Ventilation System Stair and Shaft Vent dampers (6.4.3.4.1) 9Automatically closed during normal building operation 9Interlocked to open as required by fire and smoke detection systems Shutoff Damper Controls (6.4.3.4.2) 9 All outdoor air intake and exhaust systems require motorized damper 9 Ventilation outdoor air and exhaust/relief dampers capable of automatically shutting off during / , – Preoccupancy building warm-up, cool down, and setback , (Except when ventilation reduces energy costs or when ventilation must be supplied due to code requirements) ( , .) 46 www.energycodes.gov/BECU
  47. 47. Section 6 – 6.4.3.4Controls – Ventilation System (cont’d) 9Exceptions: 9 Backdraft gravity dampers okay (BDD) – For exhaust and relief in buildings < 3 stories in height above grade 3 – Of any height in climate zones 1 – 3 1, 2, 3 9 Ventilation systems serving unconditioned spaces – 300 CFM 47 www.energycodes.gov/BECU
  48. 48. Section 6 – 6.4.3.4.3Controls - Damper Leakage Table 6.4.3.4.3 provides maximum leakage rates for outdoor air supply and exhaust dampers Table 6.4.3.4.3 Where OA supply and exhaust air dampers are required by Section 6.4.3.4 6.4.3.4 9 They shall have a maximum leakage rate when tested in accordance with AMCA Standard 500 as indicated in Table 6.4.3.4.3 AMCA Standard 500, Table 6.4.3.4.3. 48 www.energycodes.gov/BECU
  49. 49. Section 6 – 6.4.3.4.3Controls - Damper Leakage Table 6.4.3.4.3. Maximum Damper Leakage, cfm per ft2 at 1.0 in. w.g. Ventilation Air Intake Exhaust / Reflief Climate Zones Non-motorized1 Motorized Non-motorized1 Motorized 1, 2 - - - - any heigh 20 4 20 4 3 - - - - any heigh 20 10 20 10 4,5b,5c - - - - < 3 stories not allowed 10 20 10 >=3 stories not allowed 10 not allowed 10 5a,6,7,8 - - - - < 3 stories not allowed 4 20 4 >=3 stories not allowed 4 not allowed 4 49 www.energycodes.gov/BECU
  50. 50. Section 6 – 6.4.3.4.4Ventilation Fan Controls Fans with motors > 0.75 hp shall have automatic controls complying with Section 6.4.3.3.1 that are capable of shutting off fans when not required 0.75 hp , 6.4.3.3.1 , , Exception 9 HVAC systems intended to operate continuously 50 www.energycodes.gov/BECU
  51. 51. Section 6 – 6.4.3.4.5Enclosed Parking Garage Ventilation Ventilation systems in enclosed parking garages 9automatically detect contaminant levels and stage fans or 9modulate fan airflow rates to ” 50%, provided acceptable contaminant levels are maintained 50% Exception 9 Garages < 30,000 ft2 with ventilation systems that don’t use mechanical cooling or heating 30,000 ft2 9 Garages with a garage area to ventilation system motor nameplate hp ratio > 1500 ft2/hp and don’t use mechanical cooling or heating 1500 ft2/hp, 9 Where permitted by AHJ 51 www.energycodes.gov/BECU
  52. 52. Section 6 – 6.4.3.5Heat Pump Auxiliary Heat Control Controls to prevent supplementary heat when heat pump can handle the load , Exception 9Heat pumps – With minimum efficiency regulated by NAECA (NAECA) – With HSPF rating meeting Table 6.8.1B (Includes all usage of internal electric resistance heating) Table 6.8.1B ( ) 52 www.energycodes.gov/BECU
  53. 53. Section 6 – 6.4.3.6Controls - Humidifier Preheat Automatic valve to shut off preheat when humidification isn’t required , 53 www.energycodes.gov/BECU
  54. 54. Section 6 – 6.4.3.7Controls - Humidification and Dehumidification Provide means to prevent simultaneous operation of humidification and dehumidification equipment 9 Limit switches, mechanical stops, or software programming (DDC systems) Exceptions 9 Zones served by desiccant systems, used with direct evaporative cooling in series 9 Systems serving zones where specific humidity levels are required and approved by jurisdiction – Museums and hospitals , 54 www.energycodes.gov/BECU
  55. 55. Section 6 – 6.4.3.8Controls - Freeze Protection and Snow/Ice Automatic controls for , 9 Freeze protection systems – outside air temperatures > 40 F or when conditions of protected fluid will prevent freezing 40oF 9 Snow- and ice-melting systems – pavement temperature > 50 F and no precipitation is falling and outdoor temperature > 40 F 50oF 40oF 55 www.energycodes.gov/BECU
  56. 56. Section 6 – 6.4.3.9 (6.3.2q)Demand Control VentilationDCV must be provided for each zone with a area > 500 ft² andthe design occupancy > 40 people/1000 ft² where the HVACsystem has: >500 ft² >40 /1000 ft² , , 9 An air-side economizer, 9 Automatic modulating control of the OSA dampers, or , 9 A design outdoor airflow > 3,000 cfm > 3000 cfm Demand control ventilation (DCV): a ventilation system capability that provides for the automatic reduction of outdoor air intake below design rates when the actual occupancy of spaces served by the system is less than design occupancy. 56 www.energycodes.gov/BECU
  57. 57. Section 6 – 6.4.3.9Demand Control Ventilation (cont’d) Exceptions : 9 System with energy recovery complying with 6.5.6.1 6.5.6.1 9 Multiple-zone systems without DDC of individual zones communicating with a central control panel DDC 9 Systems with a design outdoor airflow less than 1200 cfm 1200cfm 9 Spaces where the supply airflow rate minus any makeup or outgoing transfer air requirement is less than 1200 cfm 1200cfm 57 www.energycodes.gov/BECU
  58. 58. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls9 Supply fans controlled by two-speed motors or variable-speed drives – Air-handling and fan coil units with chilled-water cooling coils – Supply fans with motors • 5 hp >=5hp9 At cooling demands ” 50%, supply fan controls able to reduce airflow to no greater than the LARGER of <=50%, – ½ of the full fan speed OR 1/2 , – volume of outdoor air required to meet Standard 62.1 On and after January 1, 2012 62.1 2012.1.1 , 58 www.energycodes.gov/BECU
  59. 59. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls9 Supply fans controlled by two-speed motors or variable speed drives – all AC equipment and air-handling units with direct expansion cooling and cooling capacity at AHRI conditions • 110,000 Btu/h serving single zones AHRI >=110,000Btu/h9 At control demands – 2/3 of the full fan speed OR 2/3 – volume of outdoor air required to meet Standard 62.1 62.1 59 www.energycodes.gov/BECU
  60. 60. Section 6 – 6.4.3.10 (6.3.2b)Single Zone VAV Controls (cont’d) 60 www.energycodes.gov/BECU
  61. 61. Section 6 – 6.4.4HVAC System Construction and Insulation 9 Insulation installed in accordance with industry-accepted standards 9 Insulation protection 9 Duct and plenum insulation 9 Piping insulation 9 Sensible heating panel insulation 9 Radiant floor heating 9 Duct sealing 9 Duct leakage tests 61 www.energycodes.gov/BECU
  62. 62. Section 6 – 6.4.4.1.1General Insulation installed in accordance with industry-accepted standards Insulation 9 Protected from damage due to sunlight, moisture, equipment maintenance, and wind , , 9 Exposed to weather to be suitable for outdoor service , 9 Covering chilled water piping, refrigerant suction piping, or cooling ducts located outside the conditioned space to include a vapor retardant located outside the insulation, all penetrations and joints of which to be sealed , , , 62 www.energycodes.gov/BECU
  63. 63. Section 6 – 6.4.4.1.2Duct and Plenum Insulation All supply and return ducts and plenums to be insulated per Tables 6.8.2A and 6.8.2B , 6.8.2A 6.8.2B Exceptions 9 Factory-installed plenums, casings, or ductwork furnished as part of HVAC equipment , , 9 Ducts located in heated, semiheated, or cooled spaces , 9 For runouts < 10 ft in length to air terminals or air outlets, the R-value need not exceed R-3.5 10 ft, R-3.5 9 Backs of air outlets and outlet plenums exposed to unconditioned or indirectly conditioned spaces with face areas > 5 ft2 need not exceed R-2; those ” 5 ft2 need not be insulated 5 ft2 R-2; ( ) 5 ft2 63 www.energycodes.gov/BECU
  64. 64. Section 6 – 6.4.4.1.3 (6.3.2k)Piping Insulation Tables 6.8.3A and 6.8.3B Exceptions 9 Factory-installed 9 Piping conveying fluids – design operating temperature range between 60 F-105 F, inclusive 60 F-105 F , – that haven’t been heated or cooled through the use of fossil fuels or electricity or where heat gain or heat loss will not increase energy usage , 9 Hot water piping between shut off valve and coil, not > 4 ft in length, when located in conditioned spaces , 4ft 9 Piping ” 1 in. <= 1 in. – No insulation required for strainers, control values, and balancing values , , 64 www.energycodes.gov/BECU
  65. 65. Section 6 – 6.4.4.2.1Duct Sealing Ductwork and all plenums with pressure class ratings shall be constructed to , 9 seal class A, as required to meet the requirements of 6.4.4.2.2 class A , 6.4.4.2.2 9 standard industry practice 65 www.energycodes.gov/BECU
  66. 66. Section 6 – 6.4.4.2.2Duct Leakage Tests Designed > 3 in. w.c. and all ductwork located outdoors 3 in. 9 Leak tested 9 Representative sections • 25% of the total installed duct area shall be tested 25%( ) 9 Ratings > 3 in. w.c. to be identified on drawings 3 in., 9 Maximum permitted duct leakage – Lmax = CLP0.65 • Where Lmax = maximum permitted leakage in cfm/100 ft2 duct surface area • CL = 6 cfm/100ft2 duct surface area at 1 in. wc • P = test pressure in. wc. 66 www.energycodes.gov/BECU
  67. 67. HVAC Compliance - Prescriptive Building System Compliance Options Prescriptive Envelope Option Mandatory HVAC Provisions Trade Off Energy Code (required for most Option Compliance SWH compliance options) Energy Cost Power Budget Lighting Simplified Other 67 www.energycodes.gov/BECU
  68. 68. Section 6 – 6.5HVAC Prescriptive Path 9 Economizers (Section 6.5.1) 9 Simultaneous Heating and Cooling Limitation (Section 6.5.2) 9 Air System Design and Control (Section 6.5.3) 9 Hydronic System Design and Control (Section 6.5.4) 9 Heat Rejection Equipment (Section 6.5.5) 9 Energy Recovery (Section 6.5.6) 9 Exhaust Systems (Section 6.5.7) 9 Radiant Heating Systems (Section 6.5.8) 9 Hot Gas Bypass Limitation (Section 6.5.9) 68 www.energycodes.gov/BECU
  69. 69. Section 6 – 6.5.1.1.2Control Signal Dampers capable of being sequenced with the mechanical cooling equipment and shall not be controlled by only mixed air temperature , Exception 9 Systems controlled from space temperature (such as single- zone systems) ( ) 69 www.energycodes.gov/BECU
  70. 70. Section 6 – 6.5.1.1.3High Limit Shutoff 9 Automatically reduce outdoor air intake to minimum outdoor air quantity when outdoor air intake will no longer reduce cooling energy usage , 9 Control types for specific climates from Table 6.5.1.1.3A 6.5.1.1.3A. , 9 Settings from Table 6.5.1.1.3B 70 www.energycodes.gov/BECU
  71. 71. Section 6 – 6.5.1.1.3AHigh-limit Shutoff Control Options Table 6.5.1.1.3A. High-Limit Shutoff Controls Options for Air Economizers Climate Allowed Control Prohibited Control Types Zones Types 1b, 2b, 3b, 3c, 4b, 4c, 5b, 5c, 6b, 7, Fixed Dry Bulb Fixed Enthalpy 8 Differential Dry Bulb Electronic Enthalpya Differential Enthalpy DP & DB Temperature 1a, 2a, 3a, 4a Fixed Dry Bulb Fixed Dry Bulb Fixed Enthalpy Differential Dry Bulb Differential Enthalpy DP & DB Temperature 5a, 6a Fixed Dry Bulb Differential Dry Bulb Fixed Enthalpy Electronic Enthalpya Differential Enthalpy DP & DB Temperature 71 www.energycodes.gov/BECU
  72. 72. Section 6 – 6.5.1.1.3BHigh-limit Shutoff Control Settings Table 6.5.1.1.3B. High Limit Shutoff Control Setting for Air Economizers Required High Limit (Economizer Off When) Device Type Climate Equation Description 1b, 2b, 3b, 3c, 4b, TOA>75oF OA temperature exceeds 75oF Fixed Dry Bulb 4c, 5a, 5b, 5c, 6a, TOA>70oF OA temperature exceeds 70oF 6b, 7, 8 1b, 2b, 3b, 3c, 4b, Differential Dry OA temperature exceeds return air 4c, 5a, 5b, 5c, 6a, TOA>TRA Bulb temperature 6b, 7, 8 OA enthalpy exceeds 28 Btu/lb of Fixed Enthalpy 2a, 3a, 4a, 5a, 6a hOA>28 Btu/lba dry aira Electronic OA temperature/RH exceeds the All (TOA,xRHOA)>A Enthalpy “A” setpoint curveb Differential OA enthalpy exceeds return air All hOA>hRA Enthalpy enthalpy OA Dry Bulb exceeds 75oF or DP & DB DPOA>55oF or All Outside dew point exceeds 55oF Temperature TOA>75oF (65gr/lb) 72 www.energycodes.gov/BECU
  73. 73. Section 6 – 6.5.1.1.4Dampers Return, exhaust/relief and outdoor air dampers to meet the requirements in 6.4.3 , / , 6.4.3 73 www.energycodes.gov/BECU
  74. 74. Section 6 – 6.5.1.1.5Relief of Excess Outdoor Air Means to relieve excess outdoor air during economizer operation to prevent overpressurizing the building Outlet located to avoid recirculation into the building 74 www.energycodes.gov/BECU
  75. 75. Section 6 – 6.5.1.2.1Design Capacity – Water Economizers System capable of cooling supply air by indirect evaporation and providing up to 100% of expected system cooling load at outside air temperatures of 50 F dry bulb/45 F wet bulb and below 50oF/ 45oF , 100% Exception 9 Systems primarily serving computer rooms – Where 100% of expected system cooling load at 40 F dry bulb/35 F wet bulb is met with evaporative water economizers , 40oF DB/35oF WB 100% – With dry cooler water economizers that satisfy 100% of expected system cooling load at 35 F dry bulb , 35oF DB 100% 9 Dehumidification requirements that your design can meet 100% of expected cooling load at 45 F dry bulb/40 F wet bulb with evaporative water economizers , 45oF DB/40oF WB 100% . 75 www.energycodes.gov/BECU
  76. 76. Section 6 – 6.5.1.2.2Maximum Pressure Drop - Water Economizers Precooling coils and water-to- Valve Closes In Head Economizer water heat exchangers to Pressure Control Valve In Mode Evaporator have either Cooling Tower Out Out Primary CHWP Secondary CHWP Condenser With In Heat Variable ExchangerSpeed Drive Chiller CWP Economizer CWP 9 Water-side pressure drop of 2-Way Valve < 15 ft of water OR Typical Cooling Coil Cooling 9 Bypassed when not in use Coil With Tertiary Pump , CHWS CHWR Figure 6-O from 90.1 User’s Manual 76 www.energycodes.gov/BECU
  77. 77. Section 6 – 6.5.1.3Integrated Economizer Control Economizers must be integrated with mechanical cooling systems and be capable of providing partial cooling even when additional mechanical cooling is required , 77 www.energycodes.gov/BECU
  78. 78. Section 6 – 6.5.1.4Economizer Heating System Impact Designed so economizer operation doesn’t increase the building heating energy use during normal operation , Exception 9 Economizers on VAV systems that cause zone level heating to increase due to a reduction in supply air temperature (VAV) , , 78 www.energycodes.gov/BECU
  79. 79. Section 6 – 6.5.2.1Zone Thermostatic Controls Capable of operating in sequence the supply of heating and cooling energy to the zone Controls prevent 9 Reheating 9 Recooling 9 Mixing or simultaneously supplying air previously heated or cooled 9 Other simultaneous operation of heating and cooling systems to the same zone 79 www.energycodes.gov/BECU
  80. 80. Section 6 – 6.5.2.1Zone Thermostatic Controls – Exceptions Zones for which volume of air that is reheated, recooled, or mixed is less than the larger of the following , 9 30% of zone design peak supply 30% 9 Outside air flow rate to meet 6.2 of Standard 62.1 for the zone ASHRAE Std. 62.1 6.2 9 Any higher rate that can be demonstrated to jurisdiction to reduce overall system annual energy usage 9 Air flow rate required to meet applicable codes or accreditation standards (pressure relationships or minimum air change rates) ( ) 80 www.energycodes.gov/BECU
  81. 81. Section 6 – 6.5.2.1Zone Thermostatic Controls – Exceptions (cont’d) Zones that comply with all of these 9 Air flow rate in dead band that doesn’t exceed larger of these , • 20% of zone design peak supply 20% • Outdoor air flow rate to meet 6.2 of Standard 62.1 for the zone ASHRAE Std. 62.1 6.2 • Any higher rate that can be demonstrated to jurisdiction to reduce overall system annual energy usage 9 Air flow rate that’s reheated, recooled, or mixed in peak heating demand < 50% of zone design peak supply , 50% 9 Air flow between dead band and full heating or full cooling to be modulated 9 Lab exhaust systems complying with 6.5.7.2 6.5.7.2 9 Zones where • 75% of energy for reheating or providing warm air in mixing systems is from site-recovered or site-solar source 75% 81 www.energycodes.gov/BECU
  82. 82. Section 6 – 6.5.2.1.1Supply Air Temperature Reheat Limit Zones with both supply and return/exhaust air openings > 6 ft above floor to not supply heating air > 20 F above space temperature / 6ft, 20oF 9Applies in other parts of the Standard where reheating is allowed Exceptions 9Laboratory exhaust systems complying with 6.5.7.2 6.5.7.2 9During preoccupancy building warm-up and setback 82 www.energycodes.gov/BECU
  83. 83. Section 6 – 6.5.2.2Hydronic System Controls To prevent the simultaneous heating and cooling in hydronic systems 83 www.energycodes.gov/BECU
  84. 84. Section 6 – 6.5.2.2.1Three-Pipe System No common return system for both hot and chilled water 84 www.energycodes.gov/BECU
  85. 85. Section 6 – 6.5.2.2.2Two-Pipe Changeover System 85 Diagram Courtesy of Ken Baker www.energycodes.gov/BECU
  86. 86. Section 6 – 6.5.2.2.2Two-Pipe Changeover System (cont’d) Two-pipe changeover system is allowed if it meets the following requirements: , 9 Dead band from one mode to another is • 15 F outdoor air temperature 15oF 9 Controls to allow operation of • 4 hours in one mode before changing to another mode 4 9 Reset controls so heating and cooling supply temperatures at changeover point no more than 30 F apart , 30oF 86 Diagram Courtesy of Ken Baker www.energycodes.gov/BECU
  87. 87. Section 6 – 6.5.2.2.3Hydronic (Water Loop) Heat Pump Systems Diagram Courtesy of Ken Baker 87 www.energycodes.gov/BECU
  88. 88. Section 6 – 6.5.2.2.3Hydronic (Water Loop) Heat Pump Systems (cont’d)Controls to provide heat pump water supply temperature deadband of atleast 20 F between initiation of heat rejection and heat addition by centraldevices 20oFCooling tower bypass or cooling tower isolation dampersA two-position valve at each hydronic heat pump for hydronic systemshaving a total pump system power > 10 hp 10hp ,Exception 9 If system loop temperature optimization controller is used, deadband < 20 F is allowed 88 www.energycodes.gov/BECU
  89. 89. Section 6 – 6.5.2.3Dehumidification Humidistatic controls to prevent 9 Reheating 9 Mixing of hot and cold air streams 9 Heating and cooling of same air stream 89 www.energycodes.gov/BECU
  90. 90. Section 6 – 6.5.2.3Dehumidification Exceptions 9 Systems capable of reducing supply air flow to 50%, or to minimum ventilation 50%, 9 Systems under 80,000 BTU/h that can unload at least 50% 80,000 Btu/h, 50% 9 Systems smaller than 40,000 BTU/h 40,000 Btu/h 9 Process applications (exception does NOT apply to computer rooms) ( ) 9 75% of reheat or re-cool energy is recovered or solar 75% 90 www.energycodes.gov/BECU
  91. 91. Section 6 – 6.5.2.4HumidificationSystems with hydronic cooling Valve and humidification systems Head Closes In Economizer Pressure Mode designed to maintain inside Control Valve In Evaporator Out humidity at > 35 F dewpoint Cooling Tower Out Condenser Primary CHWP Secondary CHWP With In Heat Variabletemperature shall use a water CWP Chiller ExchangerSpeed Driveeconomizer if required by 6.5.1 Economizer CWP 6.5.1 , 2-Way Valve , 35oF , Typical Cooling Coil , Cooling Coil With Tertiary Pump CHWS CHWR 91 www.energycodes.gov/BECU
  92. 92. Section 6 – 6.5.3Air System Design and Control Each HVAC system with total fan system power > 5 hp to meet 6.5.3.1 through 6.5.3.2 5 hp 6.5.3.1 6.5.3.4. 9 Fan Power Limitation 9 VAV Fan Control – Part Load Fan Power Limitation – Static Pressure Sensor location – Set Point Reset 92 www.energycodes.gov/BECU
  93. 93. Section 6 – 6.5.3.1Fan Power Limitation Table 6.5.3.1.1A Two options: nameplate hp (Option 1) fan system bhp (Option 2) Exceptions 9Hospital, vivarium, and laboratory systems that utilize flow control devices on exhaust and/or return to maintain space pressure relationships necessary for occupant health and safety or environmental control may use variable-volume fan power limitation , , , ( ) , . 9Individual exhaust fans with motor nameplate hp ” 1 hp 1 hp 93 www.energycodes.gov/BECU
  94. 94. Section 6 – 6.5.3.1Fan Power Limitation 6.5.3.1.1A Fan Power Limitation Option Limit Constant Volume Variable Volume Allowable Nameplate 1 hp CFMs*0.0011 hp CFMs*0.0015 Motor hp Allowable 2 Fan System bhp CFMs*0.00094+A bhp CFMs*0.0013+A bhp 94 www.energycodes.gov/BECU
  95. 95. Section 6 – 6.5.3.1Fan Power Limitation 6.5.3.1.1B Fan Power Limitation Pressure Drop Adjustment Device Adjustment Credits Fully ducted return and/or exhaust 0.5 in. w.c. (2.15 in. w.c. for laboratory and vivarium air system systems) Return and/or exhaust airflow 0.5 in. w.c. control devices Exhaust filters, scrubbers, or The pressure drop of device calculated at fan system other exhaust treatment design condition Particulate Filter Credit : 0.5 in. w.c. MERV 9-12 Particulate Filter Credit : 0.9 in. w.c. MERV 13-15 95 www.energycodes.gov/BECU
  96. 96. Section 6 – 6.5.3.1Fan Power Limitation 6.5.3.1.1B Fan Power Limitation Pressure Drop Adjustment Particulate Filter Credit : The pressure drop of device calculated at 2* MERV 16 and greater clean filter pressure drop at fan system and electronically enhanced filters design condition Carbon and other gas-phase air cleaners Clean filter pressure drop at fan system design condition Biosafety cabinet Pressure drop of device at fan system design condition Energy Recovery Device, other than Coil (2.2 Energy Recovery Effectiveness)-0.5 in. Runaround Loop w.c. for each airstream Coil Runaround Loop 0.6 in. w.c. for each airstream Evaporative humidifier/cooler in series with Pressure drop of device at fan system design another cooling coil condition Sound Attenuation Section 0.15 in. w.c. Exhaust system serving fume hoods 0.35 in. w.c. laboratory and vivarium exhaust systems in 0.25 in. w.c. / 100ft of vertical duct exceeding high-rise building 75ft 96 www.energycodes.gov/BECU
  97. 97. Section 6 – 6.5.3.1.2Motor Nameplate Horsepower Selected fan motor to be no larger than first available motor size greater than bhp , (BHP) Fan bhp on design documents (BHP) Exceptions 9 Fans < 6 bhp, where first available motor larger than bhp has nameplate rating within 50% of bhp, next larger nameplate motor size may be selected 6 bhp , (bhp) 50% , 9 Fans • 6 bhp, where first available motor larger than bhp has nameplate rating within 30% of bhp, next larger nameplate motor size may be selected 6 bhp( ) , (bhp) 30% , 97 www.energycodes.gov/BECU
  98. 98. Section 6 – 6.5.3.2.1Part-Load Fan Power Limitation Individual VAV fans with motors • 10 hp 10 hp( ) (VAV) 9 Must have either: – Variable Speed Drive – Vane axial fan with variable-pitch fan blades – Other controls and devices to result in fan motor demand ” 30% of design wattage at 50% of design air volume when static pressure set point = 1/3 of total design static pressure, based on manufacturer’s certified fan data – , 1/3 , 50% , 30% 98 www.energycodes.gov/BECU
  99. 99. Section 6 – 6.5.3.2.2Static Pressure Sensor Location Placed so controller set point is ” 1/3 the total design fan static pressure , 1/3 9 Except for digital control systems with zone reset capabilities where it may be at the fan discharge , Install multiple sensors in each major branch if sensor would be located downstream of a major duct split , 99 www.energycodes.gov/BECU
  100. 100. Section 6 – 6.5.3.2.3Setpoint Reset For systems with direct digital control of individual zone boxes reporting to the central control panel 9 Static pressure set point reset based on zone requiring the most pressure 100 www.energycodes.gov/BECU
  101. 101. Section 6 – 6.5.3.3Multiple-zone VAV System Ventilation OptimizationControl In multiple-zone VAV systems with DDC of individual zone boxes reporting to central control panel DDC 9 Include means to automatically reduce outdoor air intake flow below design rates in response to changes in system ventilation efficiency as per Standard 62.1, Appendix A ( Std. 62.1 A ), 101 www.energycodes.gov/BECU
  102. 102. Section 6 – 6.5.3.3Multiple-zone VAV System Ventilation OptimizationControl Exceptions Exceptions 9 VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fan-powered terminal units , , , . 9 Systems required to have exhaust air energy recovery complying with 6.5.6.1 6.5.6.1 9 Systems where total design exhaust airflow is > 70% of total outdoor air intake flow requirements 70% 102 www.energycodes.gov/BECU
  103. 103. Section 6 – 6.5.3.4Supply-air Temperature Reset Controls Multiple zone HVAC systems to have controls to automatically reset supply-air temperature in response to building loads or outdoor air temperature , , Controls to be capable of resetting supply air temperature at least 25% of difference between design supply-air temperature and design room air temperature 25% Controls that adjust the reset based on zone humidity are okay Zones expected to experience relatively constant loads to be designed for fully reset supply temperature ¸ 103 www.energycodes.gov/BECU
  104. 104. Section 6 – 6.5.3.4Supply-air Temperature Reset Controls Exceptions Exceptions 9 Climate zones 1a, 2a, and 3a 1a, 2a, 3a 9 Systems that prevent reheating, recooling or mixing of heated and cooled supply air , , 9 75% of energy for reheating is from site-recovered or site solar energy sources 75% 104 www.energycodes.gov/BECU
  105. 105. Section 6 – 6.5.4Hydronic System Design and Control HVAC hydronic systems with total pump system power > 10 hp to meet 6.5.4.1 – 6.5.4.4 10 hp , 6.5.4.1-6.5.4.4 9 Hydronic Variable Flow Systems 9 Pump Isolation 9 Chilled and Hot Water Temperature Reset 9 Hydronic (water-loop) Heat Pumps and Water-Cooled Unitary Air-Conditioners ( ) 9 Pipe Sizing 105 www.energycodes.gov/BECU
  106. 106. Section 6 – 6.5.4.1Hydronic Variable Flow HVAC pumping systems to include control valves 9 Designed to modulate or step open and close as a function of load , 9 Designed for variable fluid flow 9 Capable of reducing flow rates to ” 50% of design flow rate 50%( ) Individual pumps serving variable flow systems with a motor > 5 hp , 5 hp 9 Have controls and/or devices resulting in pump motor demand ” 30% of design wattage at 50% of design water flow / , 50% , 30% 106 www.energycodes.gov/BECU
  107. 107. Section 6 – 6.5.4.1Hydronic Variable Flow (cont’d) Differential pressure setpoint to be ” 110% of that required to achieve design flow through the heat exchanger 110% If differential pressure control and DDC controls are used DDC 9 Reset setpoint downward based on valve positions until one valve is nearly wide open 107 www.energycodes.gov/BECU
  108. 108. Section 6 – 6.5.4.1Hydronic Variable Flow Exceptions 9 Systems where – Minimum flow is < minimum flow required by equipment manufacturer for proper operation of equipment served by the system – Total pump system power ” 75 hp 75 hp( ) 9 Systems that include ” 3 control valves 3 108 www.energycodes.gov/BECU
  109. 109. Section 6 – 6.5.4.2Pump Isolation If chilled water plant has more than one chiller or boiler plant has more than one boiler 9 Provide for flow reduction when chiller or boiler is shut down , 109 www.energycodes.gov/BECU
  110. 110. Section 6 – 6.5.4.3Chilled and Hot Water Temperature Reset Controls Affects systems with design capacity > 300,000 Btu/h 300,000 Btu/h , 9 To include controls to automatically reset supply water temperatures by representative building loads (including return water temperature) or by outside air temperature ( ) Exceptions 9 If controls would result in improper operation 9 Hydronic systems with variable flow 110 www.energycodes.gov/BECU
  111. 111. Section 6 – 6.5.4.4Hydronic Heat Pumps and Water-Cooled UnitaryAir-Conditioners 9 Two-position valves at each hydronic heat pump must be provided and interlocked to shut off water flow to the heat pump when the compressor is off , Exceptions 9 Units using water economizers For hydronic heat pumps and water-cooled unitary ACs with total pump power > 5 hp 5hp 9 Controls or devices must be provided to have pump motor demand ” 30% of design wattage at 50% of design water flow / , 50% , 30% 9 This basically converts the system into a variable flow system. As such, these systems must also comply with 6.5.4.1 6.4.4.1 111 www.energycodes.gov/BECU
  112. 112. Section 6 – 6.5.4.5Pipe Sizing Chilled-water and condenser-water piping so design flow rate in each segment doesn’t exceed values in Table 6.5.4.5. , , 6.5.4.5 This table presents the maximum allowed flow rates per section of pipe as a function of the following three criteria: , – Pipe size – Annual hours of operation – System flow and control 112 www.energycodes.gov/BECU
  113. 113. Section 6 – 6.5.4.5Pipe Sizing Exceptions Exceptions 9Rates exceeding the Table are allowed if the specific section of pipe in question isn’t in the critical circuit > 30% of operating hours , 30%, 6.5.4.5 9Piping systems with equivalent or lower total pressure drop than the same system with standard weight steel pipe with piping and fittings sized per the Table 6.5.4.5 , 113 www.energycodes.gov/BECU
  114. 114. Section 6 – 6.5.5Heat Rejection Equipment Applies to heat rejection equipment used in comfort cooling systems such as 9 Air-cooled condensers 9 Open cooling towers 9 Closed-circuit cooling towers 9 Evaporative condensers Exceptions 9 Heat rejection devices included as an integral part of equipment listed devices whose energy usage is included in Tables 6.8.1A-6.8.1D , Tables 6.8.1A 6.8.1D 114 www.energycodes.gov/BECU
  115. 115. Section 6 – 6.5.5.2Fan Speed Control Fan Speed Control 9 Each fan powered by a motor • 7.5 hp 7.5 hp( ) – Have capability to operate fan at ” 2/3 full speed 2/3 – Have controls to automatically change the fan speed to control the leaving fluid temperature or condensing temperature/pressure of the heat rejection device 115 www.energycodes.gov/BECU
  116. 116. Section 6 – 6.5.5.2Fan Speed Control Exceptions Exceptions – Condenser fans serving multiple refrigerant circuits or flooded condensers – Installations in climates zones 1 and 2 1 2 – Up to 1/3 of the fans on a multiple fan application speed controlled 1/3( ) , 116 www.energycodes.gov/BECU
  117. 117. Section 6 – 6.5.5.3Limitation on Centrifugal Fan Open-CircuitCooling Towers • If towers have a combined rated capacity • 1100 gpm at 95 F condenser water return, 85 F condenser water supply, and 75 F outdoor air wet-bulb temperature , 1100gpm( ) , 95oF 85oF , 75oF – Must meet requirement for axial fan open-circuit cooling towers in Table 6.8.1G 6.8.1G Exceptions – Ducted (inlet or discharge) ( ) – Require external sound attenuation 117 www.energycodes.gov/BECU
  118. 118. Section 6 – 6.5.6.2Heat Recovery for Service Water Heating Condenser recovery required if , 9 24 hrs per day and 24 , 9 Heat rejection > 6,000,000 Btu/h and 6,000,000 Btu/h, 9 SWH load > 1,000,000 Btu/h 1,000,000 Btu/h The required heat recovery system shall have the capacity to provide the smaller of 9 60% of the peak heat rejection load at design conditions or 60%, 9 preheat of the peak service hot water draw to 85 F. 85 oF 118 www.energycodes.gov/BECU
  119. 119. Section 6 – 6.5.6.2Heat Recovery for Service Water Heating Exceptions Exceptions 9If condenser heat recovery is used for space heating with a heat recover design > 30% of peak water-cooled condenser load at design conditions , 30% 9If 60% of service water heating is provided from site-solar or site-recovered energy or other sources 60% 119 www.energycodes.gov/BECU
  120. 120. Section 6 – 6.5.7.1Kitchen Exhaust Systems • Replacement air introduced directly into hood cavity to be ” 10% of hood exhaust airflow rate 10% • Conditioned supply air to not exceed the greater of : – Supply flow required to meet space heating or cooling load – Hood exhaust flow minus available transfer air from adjacent spaces 120 www.energycodes.gov/BECU
  121. 121. Section 6 – 6.5.7.1Kitchen Exhaust Systems • If kitchen/dining facility has total kitchen hood exhaust airflow rate > 5,000 cfm, each hood’s exhaust rate must comply with Table 6.5.7.1.3 / 5000cfm , 6.5.7.1.3 – If a single hood or hood section is over appliances with different duty ratings, then the max. airflow rate for that can’t exceed the Table values for highest appliance duty rating under that hood or hood section , , Exception • If at least 75% of all replacement air is transfer air that would otherwise be exhausted 75% , . 121 www.energycodes.gov/BECU
  122. 122. Section 6 – 6.5.7.1Kitchen Exhaust Systems, con’t 9 Kitchens/dining facilities with total kitchen hood exhaust airflow rate > 5,000 cfm must have one of these: / 5000cfm , : – At least 50% of all replacement air is transfer air that would otherwise be exhausted 50% , . – Demand ventilation systems on at least 75% of exhaust air (capable of at least 50% reduction in exhaust and replacement air system airflow rates) , 75% . 50% – Listed energy recovery devices with sensible heat recover effectiveness of not less than 40% on at least 50% of the total exhaust airflow 50% , 40% 122 www.energycodes.gov/BECU
  123. 123. Section 6 – 6.5.7.1Kitchen Exhaust Systems, con’t 9 Performance testing must be done using an approved field test method 9 If demand control ventilation systems are used, additional testing is required , 123 www.energycodes.gov/BECU
  124. 124. Section 6 – 6.5.7.2Laboratory Exhaust Systems 9 Laboratory exhaust systems with total exhaust rate > 5,000 cfm to have one of the following 5,000 cfm , : 9 VAV lab exhaust and room supply system capable of reducing exhaust and makeup air flow rates and/or incorporate a heat recovery system , / 9 VAV lab exhaust and room supply systems required to have minimum circulation rates to comply with code to be capable of reducing zone exhaust and makeup air flow rates to the regulated minimum circulation values or minimum required to maintain pressurization relationship requirements , , , 9 Non-regulated zones capable of reducing exhaust and makeup air flow rates to 50% of zone design values or minimum required to maintain pressurization relationship requirements , 50% , 124 www.energycodes.gov/BECU
  125. 125. Section 6 – 6.5.7.2Laboratory Exhaust Systems (Cont’d) 9 Direct makeup air supply to equal at least 75% of exhaust air flow rate, heated no warmer than 2 F below room setpoint, cooled to no cooler than 3 F above room setpoint, no humidification added, and no simultaneous heating and cooling used for dehumidification control 75% ( ) , 2oF, 3oF, , , 125 www.energycodes.gov/BECU
  126. 126. Section 6 – 6.5.8Radiant Heating Systems Required for unenclosed spaces exception: loading docks with air curtains : 126 www.energycodes.gov/BECU
  127. 127. Section 6 – 6.5.8Radiant Heating Systems “Radiant heating systems that are used as primary or supplemental enclosed space heating must be in conformance with the governing provisions of the standard” • , 9 Radiant hydronic ceiling or floor panels 9 Combination or hybrid systems with radiant heating (or cooling) panels ( ) 9 Radiant heating (or cooling) panels used in conjunction with other systems such as VAV or thermal storage systems ( ) , 127 www.energycodes.gov/BECU
  128. 128. Section 6 – 6.5.9Hot Gas Bypass Limitation Rated capacity Maximum HGBP capacity, of system % of total capacity ” 240,000 Btu/h 50% > 240,000 Btu/h 25% 9 Applied in systems with stepped or continuous unloading 9 Limitation also pertains to chillers 9 Exception: Packaged unitary systems ” 90,000 Btu/h (7.5 tons) : 90,000 Btu/h 128 www.energycodes.gov/BECU
  129. 129. Section 6 – 6.7Submittals 9 Record drawings 9 Operating and maintenance manuals 9 System balancing 9 System commissioning 129 www.energycodes.gov/BECU

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