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• Established in 1991
• Multi-Disciplinary
• 6,000 LEED Reviews in 50+ Countries
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Guide to ASHRAE 90.1 Changes
Presentation for CxEnergy 2014
AABC Commissioning Group
L a s Ve g a s , N e v a d a
April 23, 2014
Learning Objectives
At the end of this course, participants will be able to:
1.
2.
3.
4.
Participants will learn how the ASHRAE 90.1 energy standard has
evolved in recent years up to the current version that has been
adopted.
Participants will be able to distinguish the major amendments to
the standard that have led to substantial energy improvements
from the last version.
Participants will learn how the changes to 90.1 and its Appendix
G will affect the latest version of LEED and consequentially
building energy models.
Participants will learn how the changes to the standard will impact
the building industry and particularly how it will impact
commissioning providers.
1.0 Evolution

First drafted in 1975

Major re-write of the standard in 1999

Continuous maintenance began in 2001 (every 3
years)

ASHRAE 90.1-2007 updated from 2004 via 44
addenda

ASHRAE 90.1-2010 updated from 2007 with more than
100 addenda
1.1 ASHRAE 90.1-2010 Goal

Set out to achieve a 30% energy savings when
compared to ASHRAE 90.1-2004.

Goal achievement proven by Pacific Northwest
National Laboratory (PNNL)

Substantial energy efficiency improvement when
compared to earlier iterations

Sidenote: Significant implications for LEED pursuit in
LEED v4
1.2 Major Sections

5.X Envelope

6.X Mechanical

7.X Service Water Heating

8.X Power

9.X Lighting

Appendix G (Performance Rating Method)
1.3 Compliance

5.X Envelope

6.X Mechanical

7.X Service Water Heating

8.X Power

9.X Lighting

Appendix G (Performance Rating Method)
1.4 Climate Zones
1.5 Building Prototypes









Small/Medium/Large Offices
Retail/Strip Mall
Primary/Secondary Schools
Outpatient Healthcare
Hospital
Small/Large Hotels
Warehouse
Quick/Full-Service Restaurants
Mid-Rise/High-Rise Apartments
2.0 Envelope Changes

Continuous air barrier

Cool roofs

Constraints on glazing
2.0.1 Air Barriers

A properly functioning air barrier
system provides a barrier against
both the air leakage and the
diffusion of air caused by wind,
stack, and mechanical equipment
pressures.
–
–
According to the ABAA, air leakage
can result in increased energy costs of
up to 30-40% in heating climates and
10-15% in cooling climates
The additional benefit to air barriers is
that they keep unconditioned, moist
air out of the building and reduce the
possibility of mold growth
2.1.1Continuous Air Barrier

Permeance ≤ 0.004 cfm/sf
–

Permeance ≤ 0.04 cfm/sf
–




Individual materials: plywood, insulation
board, metal
Assemblies or materials
All air barrier components must be
clear on documents
All joints, penetrations must be
detailed
Barrier must extend over all envelope
surfaces
Barrier must be design to resist
positive AND negative pressures
2.1.2 Continuous Air Barrier

Construction of barrier must include
sealing, caulking, gasketing, or
weather-stripping:
–
–
–
–

Joints (windows and doors)
Junctions of walls to foundation or roofs
Openings
Any penetrations through vapor retarders
Exceptions:
–
Semi-heated spaces in Climate Zone 1
through Zone 6
2.2 Cool Roofs

Required in Climate Zone 1 through Zone 3

Certified by ASTM
–
–
–

3 year aged solar reflectance ≥ 0.55 and
emmittance ≥ 0.75 OR
3 year aged SRI ≥ 64 OR
Increased insulation of Table 5.5.3.1.2
Numerous exceptions are noted
2.3 Glazing

Window Wall Ratio ≤ 40% of gross wall
area (prescriptive path)

Skylight roof ratio ≤ 5% of roof area

Major changes for SHGCs over 90.1-2004
which apply to all orientations

SHGC reductions through use of
overhangs
3.0 HVAC Changes

Efficiency ratings on equipment

Energy recovery

Economizers

Duct sealing/leakage

Fan power

Reheat
3.1 Simplified Approach Option

Only applies to HVAC section

Acceptable for buildings that are 1 to 2 stories
and < 25,000 sf

Must also meet 17 separate criteria
3.2 Efficiency Updates












Unitary AC and heat pumps
Single zone VAV
Water-cooled units
Packaged units and heat pumps
Water-to-water heat pumps
CRAC units
VRF
Chillers
Cooling towers
Heat exchangers
Heat pump pool heaters
Furnaces and water heating
3.3 Economizers

Comfort cooling
–
–

Computer rooms
–
–

Not required for 1A and 1B
Required for all other zones where the cooling
capacity is ≥ 54,000 Btu/h
Not required in 1A, 1B, 2A, 3A, 4A
Required in other zones dependent on tonnage
Exempt:
–
If able to prove efficiency improvement for the
climate zone
3.4 Waterside






Two-position valves in water-cooled units (i.e.
SWUD units)
Variable flow/pumping
Pump pressure optimization
No regulation downstream of booster pumps
Maximum flows in nominal pipe sizes
Significant insulation upgrades, particularly for
steam and hot water systems
3.5.1 Airside








Ventilation optimization
Supply air temp reset
Limitation on damper leakage
Dual maximum for VAV terminal units
Overhead heating temp limit
Lab VAV exhaust air
Demand control ventilation
Fan power limitation
3.5.2 Airside

Exhaust air energy recovery
4.0 Lighting Changes

Lighting power density improvements

Exterior building lighting updates

Grounds lighting
4.1 Lighting Power Density

Most spaces defined in standard have
lower LPDs than 2007 and reductions
are substantial

Important to keep in mind impact of
these requirements on cooling and
heating load calculations

Average reduction of 16.2% in LPDs
versus 90.1-2007
4.2 Auto Shutoff/Dimming

Time clock with separate shutoff for each floor
or building > 25,000 sf OR

Occupancy sensors set to 30 minutes

Separate signal from controls indicated the
space is unoccupied

Daylight switching for daylit areas > 250 sf
OR
4.3 Exterior Lighting

Turn off when adequate daylight available

Façade and landscape lighting off between
closing or midnight and 6 am or opening

Reduced lighting of advertising overnight

Reduction in lighting power densities,
depending on zone
5.0 LEED EAp2 Impact

LEED v2009 requires a 10% energy cost
savings when compared to the baseline
building as defined by ASHRAE 90.1-2007

LEED v4 requires a 5% energy cost savings
when compared to the baseline building as
defined by ASHRAE 90.1-2010
5.1 LEED EAc1 Impact
EAc1 Point Comparison
60%
54%
50%
50%
46%
44%
42%
46%
40%
38%
40%
42%
36%
34%
35%
30%
28%
v4
32%
26%
29%
24%
22%
26%
20%
24%
18%
20%
v2009
38%
32%
30%
50%
48%
22%
16%
20%
14%
18%
16%
14%
10%
12%
10%
8%
6%
0%
0
2
4
6
8
10
12
14
16
18
20
6.0.1 Energy Modeling Impact

Appendix G
–
–
–
–
Section G1.4 has been revised to include a more
detailed list of required documentation to be
submitted to the rating authority.
Section G2.5 has been revised to more clearly
explain the Exceptional Calculation Method
procedure and what documentation is required to
justify the results.
Section G3.1.1 includes new exceptions for
additional system types for kitchens and heated
only spaces (new Baseline system types 9 and 10).
Section G3.1.1.1 through Section G3.1.1.3 provide
new guidance for modeling district heating and
cooling systems.
6.0.2 Energy Modeling Impact

Appendix G (continued)
–
–
–
–
Table G3.1(14) includes new guidance regarding
“exterior conditions” (adjacent structures and
terrain, ground temperatures, and water main
temperatures).
Section G3.1.2.6 has been revised to more clearly
explain how to take credit for improved ventilation
systems (i.e. demand control ventilation)
Section G3.1.2.9 includes new provision for sizing
supply air volumes in the Baseline model for
laboratories.
Section G3.1.3.13 includes additional requirements
for VAV minimum setpoints in the Baseline model
for laboratories.
7.0 Impact on Building Industry




Jump in energy performance requirements to
drive vendors to be more aggressive
Architects, engineers and contractors will have
a learning curve on new requirements
Initially expect increased cost of construction
while industry catches up
Even more importance now on technical
competence across all trades, but specific
focus on controls technicians that are required
to implement more complex strategies
7.1 Impact on Commissioning

Elevated performance requirements leading to
more complex building systems
–
–
–


HVAC and Controls
Lighting controls
Integration of other systems
Commissioning providers required to be
knowledgeable on optimization requirements
stipulated in energy code
Opportunity for commissioning professionals
to provide guidance and lessons learned on
success of optimization strategies to design
engineers
7.2 References
http://www.seco.cpa.state.tx.us/tbec/videos.php
http://www.pnnl.gov/publications/abstracts.asp?report=3
58270
Conclusion
Knowledge acquired:
1.
2.
3.
4.
Participants learned how the ASHRAE 90.1 energy standard has
evolved in recent years up to the current version that has been
adopted.
Participants are able to distinguish the major amendments to the
standard that have led to substantial energy improvements from
the last version.
Participants learned how the changes to 90.1 and its Appendix G
will affect the latest version of LEED and consequentially building
energy models.
Participants learned how the changes to the standard will impact
the building industry and particularly how it will impact
commissioning providers.
Questions
Please feel free to ask any questions you may have for today’s
course presenters.
Thank You For Your Time
About Us
• Established in 1991
• Multi-Disciplinary
• 5,500 LEED Reviews in 50+ Countries
• 8(a) Certified; Small Disadvantaged
Business; 8(m) WOSB
Epsten Group Services:
Commissioning
Retro-Commissioning
Building Envelope Services
Roofing & Waterproofing Consulting
Architecture & Interior Design
LEED Consulting
Energy Modeling