INTRODUCTION TO: ASHRAE STANDARD 90.1, 2013 HVAC System Requirements for Reducing Energy Consumption in Commercial Buildings Rocky Mountain ASHRAE Technical Conference, April 29, 2016
SEAN BEILMAN, P.E., HBDP, LEED AP BD+C 14 yrs as a Mechanical Engineer 9 yrs at BCER Engineering ASHRAE SSPC 90.1 Committee Member ECB Subcommittee Technical Editor of the 90.1, 2013 User s Manual Technical Editor of the 189.1, 2014 User s Manual 2
PRESENTATION TOPICS (NOT EXHAUSTIVE) Standard 90.1 Overview Equipment Efficiency Controls Fan Power/Efficiency Exhaust Air Energy Recovery Central Hydronic Plant HVAC Construction Computer Room Cooling 3
4 90.1 OVERVIEW
SECTIONS Section 1 Purpose Section 2 Scope Section 3 Definitions Section 4 Administration and Enforcement Section 5 Envelope Section 6 Mechanical (HVAC) Section 7 Service water heating Section 8 Power electricity distribution losses, transformers, etc. Section 9 Lighting Section 10 Other equipment elevators, escalators, booster pumps, motor efficiency Section 11 Energy Cost Budget 5
COMPLIANCE PATHS Comply with all mandatory provisions in the Standard AND Prescriptive Provisions of Each Section OR Performance Provisions of Each Section OR Section 11, Energy Cost Budget MANDATORY PROVISIONS X.4 PRESCRIPTIVE PROVISIONS X.5 PERFORMANCE PROVISIONS X.6 SECTION 11 6
EQUIPMENT PERFORMANCE 7 MANDATORY EFFICIENCIES
EQUIPMENT PERFORMANCE TABLES (6.8.1) Chillers Packaged Equipment Split Systems Furnaces Boilers PTACs VRFs Heat Pumps CRACs Etc. 8
EQUIPMENT PERFORMANCE TABLES (6.8.1) Equipment must meet the efficiencies at the rating conditions. NOT the specific conditions of the project Excluding chillers operating at nonstandard chilled water conditions 9
EQUIPMENT PERFORMANCE TABLES (6.8.1) Efficiency focuses on full load efficiency AND annualized efficiency Systems rarely, if ever operate at full load Mechanical efficiencies have reached diminishing return Inexpensive controls enable improved part load efficiency 10
EQUIPMENT PERFORMANCE TABLES (7.8) Gas/oil Water Heaters Electric Water Heaters Instantaneous Storage Tank Pool Heaters 11
ELECTRIC MOTOR PERFORMANCE TABLES (10.8) General Purpose Polyphase Small ( 3HP) Capacitor-Start Motors ( 3HP) Fire Pump Motors 12
13 MECHANICAL CONTROLS
MANDATORY DIRECT DIGITAL CONTROLS (6.4.3.10) DDC Systems are now mandatory in many applications Larger new building applications dependent upon: Type and size of equipment Also required in many renovations dependent upon: Scope of renovation Type and size of new equipment Existing control system 14
MANDATORY DIRECT DIGITAL CONTROLS (6.4.3.10) 15
DDC CAPABILITY (6.4.3.10.2) Monitor: Zone demand Duct pressure Hydronic pressure Transfer zone information from zone controller to plant controllers Automatically identify problem zones Allow removal of problem zones from reset logic Trend and Display points 16
MANDATORY HVAC CONTROLS Deadband Must maintain 5 F between heating and cooling space temp setpoints Automatic Shutdown Shutdown the system when occupants are not present Night Setback Relaxed thermostat setpoints during unoccupied periods. Increase 5 F in cooling. Reduce 10 F in heating Optimum Start Reduce the amount of time it takes to bring spaces to occupied temperature setpoint. Damper and Fan Shutoff Controls Motorized OA and EA dampers must close. Exhaust fans must stop. 17
VARIABLE PARKING GARAGE EXHAUST (6.4.3.4.5) Applies to enclosed parking garages Monitor garage contaminant level (CO2, CO, NOx) Adjust exhaust rate to maintain adequate indoor air quality Setpoints are not dictated by 90.1 Min exhaust rate must not be more than 50% of the design airflow 18
DEMAND CONTROL VENTILATION (6.4.3.8) Occupant Density (reduced for 2013) 2010 Threshold 40 people/1000 ft 2 2013 Threshold 25 people/1000 ft 2 New threshold aligns with green rating systems Change will require DCV in many spaces which previously did not require it. Notably, classrooms 19
VAV VENTILATION OPTIMIZATION (6.5.3.3) Reset the outdoor airflow rate at the VAV air handler based on ASHRAE Standard 62.1 Ventilation Rate Procedure. Requires two way communication between the AHU controller and the VAV terminal controllers Must measure/communicate: VAV terminal airflow Zone occupancy (densely occupied spaces) Supply air temperature AHU Outdoor airflow 20
ECONOMIZER (6.5.1) Systems exceeding the following thresholds must have economizer (air or water) 54,000 btu/h (comfort cooling) 65,000 btu/h (computer room cooling) In Denver 135,000 btu/h in other climate zones No economizer requirements in Climate zones 1a and 1b 21
AIR ECONOMIZER (6.5.1.1.3) Acceptable control methods have changed Dry bulb or enthalpy control only 22
WATER ECONOMIZER (6.5.1.2) May be used in lieu of Air Economizer Must provide 100% of the expected cooling load @ 50 F db/45 F wb outdoor air conditions Additional waterside components (HX or precooling coils) must not add more than 15ft of water pressure. If so, add a secondary loop or a bypass 23
INTEGRATED ECONOMIZER (6.5.1.3) All economizers must be integrated Additional requirements added for DX cooling Prohibits/limits false loading mech cooling Min compressor run time OA damper may not close until SAT <45 F Single zone systems must have at least 2 cooling stages (Capacity dependent) Variable air volume systems must have 3 or 4 cooling stages (Capacity dependent) 24
ECONOMIZER & HUMIDIFICATION (6.5.1.6) When humidification maintains indoor air wetbulb temp. >35 F: Airside economizer is prohibited Water Economizer must be used This is not a new requirement: Moved from 6.5.2.4 in 2010 to a more relevant section in 2013 25
HUMIDIFICATION AND DEHUMIDIFICATION (6.4.3.6) Active humidification limited to 30% RH in the warmest zone Active dehumidification limited to 60% RH in the coolest zone Active humidification and dehumidification may not operate simultaneously NO HUMIDIFICATION OR DEHUMIDIFICATION ACTIVE DEHUMIDIFICATION ACTIVE HUMIDIFICATION 26
HUMIDIFICATION AND DEHUMIDIFICATION (6.4.3.6) Exceptions: Direct evap cooling used with a desiccant Museums, hospitals, etc where a 10% humidity deadband is used (as approved by AHJ) Critical environment where RH must be maintained within ±5% (as approved by AHJ) 27
cooling heating SIMULTANEOUS HEATING AND COOLING (6.5.2) HVAC controls must prevent: Reheating Recooling Mixing of heated and cooled air Any form of simultaneously heating and cooling a zone AIRFLOW AIRFLOW 28 NOT allowed unless..
SIMULTANEOUS HEATING AND COOLING EXCEPTIONS (6.5.2) With DDC reheat/recool allowed provided: Deadband flow less than the max of 20% of the max SA flow Flow require for code ventilation Higher SA flow that reduce OA flow Higher flow to maintain pressure relationships Reheated/recooled flow 50% of max SA flow 1 st heating stage increases SAT only 2 nd heating stage increases SA flow 29
SIMULTANEOUS HEATING AND COOLING EXCEPTIONS (6.5.2) With DDC reheat/recool (continued) 30 Figure courtesy ASHRAE 90.1, 2013 Users Manual
SIMULTANEOUS HEATING AND COOLING EXCEPTIONS (6.5.2) Without DDC reheat/recool no more than the max of: 30% of the max SA flow Flow require for code ventilation Higher SA flow that reduce OA flow Higher flow to maintain pressure relationships 31 Figure courtesy ASHRAE 90.1, 2013 Users Manual
SUPPLY AIR TEMPERATURE RESET (6.5.3.4) To minimize Reheat: VAV Systems must include Supply Air Temperature reset logic Requires two way communication between the AHU and the VAV terminal controllers Maintain the highest supply air temperature setpoint that satisfies all zones in cooling. 32
FAN CONTROL (6.5.3.2) Cooling load met by adjusting cooling capacity (typical single zone system) Minimum of 2 fan speeds 100% flow @ 100% design fan power 66% flow @ 40% design fan power Must have at least two speeds of operation when using air economizer 33
FAN CONTROL (6.5.3.2) Cooling load met by adjusting air flow (typical VAV system) Modulate fan speed between the following points 100% flow @ 100% design fan power 50% flow @ 30% design fan power Must have at least two speeds of operation when using air economizer (but would likely just modulate) 34
ELECTRICAL ENERGY MONITORING (8.4.3) Measurement devices to monitor and store hourly energy data for the following utility energy types for 36 months: Total electrical energy HVAC systems Interior lighting Exterior lighting Receptacle circuits 35
WHOLE-BUILDING ENERGY MONITORING (10.4.5) Measurement devices to monitor and store hourly energy data for the following utility energy types for 36 months: Natural gas Fuel oil Propane Steam Chilled water Heating water 36
EXCEPTIONS TO ENERGY/ELECTRICAL MONITORING (10.4.5 AND 8.4.3) Energy monitoring is NOT required for: Buildings or additions < 25,000 ft 2 Tenant spaces < 10,000 ft 2 Dwelling units Residential buildings with common area < 10,000 ft 2 Fuel/electricity for emergency equipment 37
38 FAN POWER & EFFICIENCY
FAN POWER (6.5.3.1) Two Methods Nameplate HP (Option 1), less work and less flexible Brake HP method (Option 2), more work and more flexible The allowance is for ALL fan motors in a fan system, not each individually Supply, return, relief, exhaust 39
FAN POWER (6.5.3.1) Fan power is the sum of all the fan motors Common pressure credits using Option 2 Hepa filtration Return air control devices Evap cooling Fully ducted return Heat recovery 40
FAN POWER (6.5.3.1) In 2013 the pressure drop adjustments changed Modified sound attenuation credit (added sound level goal) Added deductions for elimination of heating coils 41
FAN EFFICIENCY (6.5.3.1.3) In addition to fan power requirements Fan must have a Fan Efficiency Grade (FEG) of not less than 67 (per AMCA 205) The fan efficiency at design conditions must be within 15 efficiency percent of the max total fan efficiency Many exceptions, notably Small fans Fans part of equipment rated as a package 42
FAN EFFICIENCY GRADE (6.5.3.1.3) Fans must have an FEG of 67 (AMCA 205) 43 Figure courtesy AMCA 205
FAN EFFICIENCY GRADE (6.5.3.1.3) Efficiency at design must be within 15 percentage points of the fan s maximum efficiency 57% 48% Δ = 9% This fan selection complies with the total efficiency requirement 44 Figure courtesy Greenheck CAPS
FRACTION HP FAN MOTORS (6.5.3.5) Motors 1/12 HP and < 1 HP must be: Electronically Commutated Motors (DC Brushless) 70% Efficient (rated in accordance with DOE 10 CFR 431) Exceptions: Heating only applications (fan in airstream) Motors in space conditioning equipment rated as a package Motors already covered in Chapter 10 of 90.1 45
EXHAUST AIR ENERGY RECOVERY 46
EXHAUST AIR ENERGY RECOVERY (6.5.6) 50% Effective The change in outdoor air enthalpy must be 50% of the difference between the outdoor enthalpy and the return enthalpy Arid climates and unbalanced flow can be a challenge 47
EXHAUST AIR ENERGY RECOVERY (6.5.6.1) Exhaust air energy recovery based on run time 48
49 CENTRAL HYDRONIC PLANT
CENTRAL HYDRONIC PLANT REQUIREMENTS (6.5.4) The following requirements were introduced in 2010 Supply water temperature reset Reset chilled and heating water setpoints on OAT or demand No reset amount specified Variable flow pumping when Total pump power > 10HP OR Single pump power > 5HP 50
CENTRAL HYDRONIC PLANT REQUIREMENTS (6.5.4) Boiler and Chiller Isolation (6.5.4.3) Water must not flow through boilers or chillers that are staged off If primary/secondary pumping is used Pump QTY = Boiler (or chiller) QTY Excludes chillers in series Results Reduced pump energy Increased ΔT through running equip. 51
CENTRAL HYDRONIC PLANT REQUIREMENTS (6.5.4) The following figure applies to both chillers and boilers 52 Figure courtesy ASHRAE 90.1, 2013 Users Manual
BOILER PLANT TURNDOWN (6.5.4.1) Boiler plants 1,000,000 btu/h must meet minimum turndown ratio Plant must modulate from the minimum turn down to the maximum fire May use multiple boilers to satisfy the requirement (not all must meet the requirement) 53
HVAC CONSTRUCTION
DAMPER LEAKAGE (6.4.3.4.3) DENVER & Front Range 55
DUCT SEALING/LEAKAGE (6.4.4.2) Seal ALL ductwork to Seal Class A Tape is not allowed Use mastic to seal all joints and seams Test ductwork located outdoors or designed to operate above 3in.W.C. Max leakage is a function of the design operating pressure. 56
DUCT INSULATION (6.4.4.1.2) 57
PIPING SIZING (6.5.4.6) Chilled Water and Condenser Water pipe sizing requirements. 58
PIPING INSULATION (6.4.4.1.3) 59
PUT IT ALL TOGETHER Applying 90.1, 2013 to a Gas/DX VAV System with Hydronic Reheat
COMPLIANT GAS/DX VAV REHEAT SYSTEM WITH HYDRONIC REHEAT Fan Speed Control (Part Load Power) System Fan Power OA Airflow Station Sensor Accuracy Packaged EER DDC System Duct Static Sensor Location OAT Sensor Integrated Economizer Ventilation Optimization Compressor Steps & Hot Gas Bypass Limit Duct Static Reset SAT Reset Burner Efficiency 61
COMPLIANT GAS/DX VAV REHEAT SYSTEM WITH HYDRONIC REHEAT CO 2 or Occupancy Sensor Tstat or Temp Sensor w/ 5 F Deadband Heating SAT Setpoint Max reheated CFM SAT Sensor Modulating Control Valve Airflow Station DDC Controller Max Deadband CFM 62
COMPLIANT GAS/DX VAV REHEAT SYSTEM WITH HYDRONIC REHEAT Measure Building Fuel Usage Max Pressure Setpoint Pressure Setpoint Reset CV Pump Exception Boiler Isolation Boiler Plant Turndown Variable Speed Flow HWS Temp Reset 63
64 COMPUTER ROOM COOLING (DATA CENTERS)
CRAC UNITS 90.1 Scope Changed in 2010 Included equipment for process cooling CRAC Unit requirements are scattered throughout the standard Variable air flow Humidification Dehumidification Efficiencies Economizer 65
CRAC UNIT ECONOMIZER (6.5.1.2.1) Water economizer requirements have changed Table 6.5.1.2.1 provides ambient conditions at which the water economizer must satisfy 100% of the cooling load 66
SECTION 6.6 Computer Rooms (and Data Centers) may use Section 6.6 as an alternative compliance path using PUE PUE: Power Usage Effectiveness Reference: Recommendations for Measuring and Reporting Overall Data Center Efficiency v2 17 May 2011, The Green Grid 67
SECTION 6.6 PUE 1 Table 6.6.1 or PUE 0 Table 6.6.1 PUE 1 Computer Room Energy IT Equipment Energy Hourly Annual Energy Consumption using Appendix G PUE 0 Computer Room Power IT Equipment Power Peak Power Demand using Outdoor Design Cooling Conditions at 100% and 50% IT Equipment Power 68
THANK YOU 69 Questions?