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INTRODUCTION TO:
ASHRAE STANDARD 90.1, 2013HVAC 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
90.1 OVERVIEW
4
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 Budget5
COMPLIANCE PATHS
6
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
EQUIPMENT PERFORMANCE
MANDATORY EFFICIENCIES7
EQUIPMENT PERFORMANCE TABLES
(6.8.1)
Chillers
Packaged Equipment
Split Systems
Furnaces
Boilers
8
PTACs
VRFs
Heat Pumps
CRACs
Etc.
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
MECHANICAL CONTROLS
13
MANDATORY DIRECT DIGITAL CONTROLS
(6.4.3.10)
14
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
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 setpointsduring 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 ft2
2013 Threshold ≥25 people/1000 ft2
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
26ACTIVE
HUMIDIFICATION
ACTIVE
DEHUMIDIFICATION
NO HUMIDIFICATION OR
DEHUMIDIFICATION
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
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
28
NOT allowed unless…..
AIRFLOW
co
olin
g
heating
AIRFLOW
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
1st heating stage increases SAT only
2nd 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 ft2
Tenant spaces < 10,000 ft2
Dwelling units
Residential buildings with common area < 10,000 ft2
Fuel/electricity for emergency equipment
37
FAN POWER & EFFICIENCY
38
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
44
48%
57%
Δ = 9%This fan selection
complies with the
total efficiency
requirement
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
CENTRAL HYDRONIC PLANT
49
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)
55
DENVER & Front Range
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
61
Packaged EER
Burner Efficiency
System Fan Power
Integrated
Economizer
Compressor Steps &
Hot Gas Bypass Limit
SAT Reset
Duct Static Reset
Fan Speed Control
(Part Load Power)
Duct Static
Sensor Location
DDC System
Ventilation
Optimization
Sensor
Accuracy
OA Airflow
Station
OAT
Sensor
COMPLIANT GAS/DX VAV REHEAT
SYSTEM WITH HYDRONIC REHEAT
62
Max Deadband CFM
SAT SensorCO2 or
Occupancy
Sensor Airflow Station
DDC Controller
Tstat or Temp
Sensor w/
5°F Deadband
Max “reheated”
CFM
Heating SAT
Setpoint
Modulating
Control Valve
COMPLIANT GAS/DX VAV REHEAT
SYSTEM WITH HYDRONIC REHEAT
63
Boiler Isolation
Boiler Plant
Turndown
Variable Speed
Flow
HWS Temp Reset
CV Pump
Exception
Max Pressure Setpoint
Pressure Setpoint Reset
Measure Building
Fuel Usage
COMPUTER ROOM COOLING
(DATA CENTERS)64
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
PUE1 ≤ Table 6.6.1
or
PUE0 ≤ Table 6.6.1
68
PowerEquipment IT
Power RoomComputer PUE 0
EnergyEquipment IT
Energy RoomComputer PUE1
Hourly Annual Energy Consumption using
Appendix G
Peak Power Demand using Outdoor Design
Cooling Conditions at 100% and 50% IT
Equipment Power
THANK YOUQuestions?
69
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