ASHRAE Journal - November 2019 - 14

TECHNICAL FEATURE

TABLE 2 Benchmark PEI values (ASHRAE/IES Standard 90.1-2013).
CLIMATE HI-RISE MID-RISE HOSPITAL LARGE SMALL LARGE
ZONE
APT
APT
HOTEL HOTEL OFFICE

MEDIUM SMALL OUTPATIENT
OFFICE OFFICE
CLINIC

FAST RESTAURANT STAND
FOOD
ALONE
RETAIL

STRIP PRIMARY SECONDARY WAREHOUSE
MALL SCHOOL
SCHOOL

Miami

1A

3.6

2.9

3.3

3.6

2.8

1.9

2.7

3.7

2.7

1.7

2.0

6.3

9.2

2.8

3.5

4.5

Houston

2A

3.4

2.8

3.2

3.5

2.7

1.8

2.6

3.6

2.6

1.8

2.1

6.1

9.5

2.8

3.3

5.1

Phoenix

2B

3.6

2.9

3.0

3.3

2.7

1.9

2.6

3.8

2.5

1.8

2.1

6.7

9.8

2.7

3.4

6.3

Memphis,
Tenn.

3A

3.7

3.0

3.3

3.4

2.7

1.8

2.6

3.6

2.6

2.0

2.2

6.0

9.9

2.9

3.2

6.2

El Paso,
Texas

3B

3.3

2.8

3.0

3.1

2.6

1.8

2.4

3.5

2.3

1.8

2.1

6.2

8.9

2.4

3.1

5.6

San Francisco

3C

2.8

2.5

2.9

2.9

2.5

1.5

2.0

3.1

2.1

1.9

2.0

5.0

7.6

2.3

2.7

6.0

Baltimore

4A

3.8

3.1

3.3

3.3

2.8

1.8

2.5

3.4

2.5

2.1

2.8

5.9

10.4

2.9

3.0

7.2

Albuquerque,
N.M.

4B

3.5

2.9

3.0

3.1

2.7

1.8

2.3

3.5

2.3

1.9

2.2

6.2

10.1

2.6

3.2

6.4

Salem, Mass.

4C

3.5

2.9

3.0

3.1

2.6

1.7

2.3

3.3

2.2

2.0

2.3

6.1

9.5

2.6

3.3

6.8

Chicago

5A

4.3

3.5

3.4

3.4

2.9

2.0

2.8

3.4

2.5

2.3

2.6

6.2

12.0

3.0

3.1

9.2

Boise, Idaho

5B

3.7

3.1

3.1

3.2

2.7

1.8

2.4

3.6

2.3

2.1

2.4

6.7

10.2

2.7

3.5

7.2

Vancouver,
Wash.

5C

3.6

3.0

3.1

3.1

2.7

1.7

2.3

3.2

2.2

2.1

2.4

6.2

10.1

2.6

2.9

7.4

Burlington,
Vt.

6A

4.3

3.5

3.4

3.4

3.0

2.0

2.8

3.5

2.5

2.4

2.8

6.3

12.6

3.0

3.0

9.6

Helena, Mont.

6B

3.9

3.3

3.2

3.3

2.9

1.9

2.6

3.5

2.4

2.3

2.6

6.1

11.4

2.8

2.9

8.4

Duluth, Minn.

7

4.8

3.9

3.5

3.5

3.2

2.1

2.5

3.9

2.6

2.7

3.1

6.8

14.1

3.2

3.2

13.0

Fairbanks,
Alaska

8

5.6

4.6

3.8

4.3

3.6

1.8

3.1

4.8

3.0

3.2

3.8

8.4

18.2

4.1

4.3

13.1

reflect the typical range of values for modern office environments developed through ASHRAE RP-1742.4
Cases O1 and O2 allow an independent study of the
impact of differences of occupant density alone on PEI
and EUI. This represents the increasing occupant densification of spaces in existing buildings, with no additional ventilation control management and process load
as a neutral variable.
Cases C1 and C2 represent trends in high-performance
building design and operation, where systems, including process loads scale in parallel with occupant load.
We hypothesized the following:
* PEI values would be lower for a given building type
in less extreme climate zones. While climate normalized data is often referenced, it generally makes sense
that it is more energy intensive to operate a building
in certain climate zones. The PUE concept for data
centers has shown the incredible benefits of building
these centers in climates with a significant number of
economizer cooling hours (High-Performance PUE =
1.0 to 1.2).
14

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N O V E M B E R 2 0 19

* There would be a correlation between PEI and EUI,
with a fixed process load. PEI would show a stronger correlation for office and education building types, where
ventilation-driven processes are non-dominant.
* Results plotted for a given building type and climate
zone would show non-linear behavior for the two occupancy load cases and for the two combination cases.
The research would evaluate whether there are any clear
trends for inflection points in the trend data, showing
the potential for optimization.

Results
Tables 2 and 3 present benchmark PEI and EUI values,
respectively, for ASHRAE/IES Standard 90.1-2013 reference cases. These are based on simulation results precomputed and available at https://www.energycodes.
gov/development/commercial/prototype_models.
PEI exhibits a wide range from a low of 1.5 for a large
office in Climate Zone 3C to a high of 18.2 for a Strip Mall
retail typology in Climate Zone 8. The results show that
very different building types, with very different EUI
https://www.energycodes.gov/development/commercial/prototype_models https://www.energycodes.gov/development/commercial/prototype_models
ASHRAE Journal - November 2019

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