introduction to ashrae standard 90.1,...

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.


(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


(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


(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


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


EXCEPTIONS (6.5.2)

With DDC reheat/recool (continued)

30

Figure courtesy ASHRAE

90.1, 2013 Users Manual


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



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


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



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



The following figure applies to both chillers and boilers

52



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



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



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

introduction to ashrae standard 90.1,...

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