hting,
HVAC, and Plumbing
High-Performance Engineering Design
Lighting System Design
Mechanical System Design
Central Plant Systems
Plumbing and Water Use
Building Control Systems
Electrical Power Systems
Metering
LANL | Chapter 5
High-Performance Engineering Design
Lighting, HVAC,
and Plumbing
By now, the building envelope serves multiple roles.

It protects the occupants from changing weather condi­

tions and it plays a key part in meeting the occupants

comfort needs. The heating, ventilating, air-conditioning,

and lighting (HVAC&L) systems complement the archi­

tectural design, govern the buildings operation and

maintenance costs, and shape the buildings long-term

environmental impact. The architectural design maximizes the potential
for a high-performance building, but it is the
engineering design that actually makes the
building a high-performance building.
Designers of high-performance buildings depend on
building energy simulation tools to understand the
complicated interactions between the HVAC&L systems
and the building envelope (see Appendix F). These
tools also prove invaluable to the designer when com­
paring HVAC&L strategies and selecting the best
systems to meet the buildings lighting and space con­
ditioning requirements. High-performance buildings
cannot be designed using only rules of thumb or
conventional wisdom.
Los Alamos National Laboratory Sustainable Design Guide
81
The LANL Ion Beam Facility mechanical room.
LANL Chapter 5
|
Lighting, HVAC, and Plumbing
Lighting System Design
The single largest operating cost of commercial build­
ings in the U.S. is lighting. Lighting systems represent
one-third or more of the total electrical energy costs of
a commercial building. They also introduce heat into
the space and increase building cooling loads. Because
lighting systems significantly impact a buildings operat­
ing cost and energy performance, evaluate options for
the lighting systems before considering strategies for a
low-energy HVAC system. Also, take advantage of day-
lighting opportunities whenever possible.
HVAC System Design
Space conditioning loads are a close second to lighting
systems in terms of the most costly components to
operate in commercial buildings in the U.S. Through
good architectural design resulting from the engineer
participating in the architectural design process, the
building will have daylighting, solar gain avoidance,
and other energy-efficient architectural strategies. In
other words, the envelope will minimize heating, cool­
ing, and lighting energy loads. It is the engineers
responsibility to design the HVAC systems to comple­
ment the architectural design.
Lighting systems constitute 30% to 50% of
the total annual electrical energy consumption
in U.S. office buildings. In the Federal sector,
lighting accounts for 25% of the total electricity
consumed annually.
A building designed to take advantage of daylighting
will have electric lighting system controls that turn the
electric lights off or dim them when sufficient daylight­
ing is available. The electric lights operate only to main­
tain set lighting conditions that the daylighting cannot
meet. Less waste heat from the electric lighting system
is then introduced to the space, which in turn reduces
the buildings cooling loads.
Building Heat Gains
from Different Sources of Light
(Watts per 1000 lumens)
Remember to account for the benefits of good
lighting design primarily reduced cooling
loads when sizing the HVAC system.
Spectrally selective
tinted low-e glass
Clear glass
T-8 fluorescent w/
electronic ballast
Incandescent
4.6
7.4
11.7
57
well-engineered lighting design
Characteristics of a
Consider advanced engineering design strategies early
in the design process to allow time for making modifi­
cations to the architectural design to accommodate
these strategies. Use computer simulation tools to eval­
uate the effect of the advanced architectural strategies
when calculating HVAC system loads (see Appendix F).
Also, be familiar with the intended building activities
The solar heat gains from a good daylighting system
and the resulting impact on internal loads.

Saves energy costs and decreases polluting
power plant effluents.

Responds to the varying daylight levels
throughout the day.

Improves indoor environmental quality
making occupants more comfortable and
productive.
0
10
20
30
40
50
60
can be less than half of the heat gains from the most

Tailors to individuals lighting needs through-
out the building.

Decreases building cooling loads resulting
in smaller, less expensive space cooling
equipment.
Los Alamos National Laboratory Sustainable Design Guide
82
efficient current electric lighting system technologies,
to achieve equal lighting levels in a space.
The LANL Ion Beam Facility mechanical room.
LANL Chapter 5
|
Lighting, HVAC, and Plumbing
Lighting System Design
Just a reminder
A well-thought-out building envelope design
for the Los Alamos climate will reduce the
buildings primary lighting, heating, and cool­
ing loads. The engineered systems within the
building envelope will meet those additional
lighting, heating, and cooling loads that the
envelope cannot offset. Designing the enve­
lope to be compatible with the climate and
designing the engineered systems to truly work
with the envelope is a non-traditional method
of building design. This method offers consid­
erable potential for achieving high-perfor­
mance buildings in the uniquely suitable
Los Alamos climate.
Plug and process loads impact the HVAC system design,
especially in buildings housing energy-intensive labora­
tory and research activities. Recommend energy-saving
The architectural design of a high-performance building
maximizes the use of daylighting in the building. The
engineering design integrates the electric lighting sys­
tem design with the architectural design to supplement
the changing daylighting levels and maintain constant
prescribed lighting levels in the space, using the most
efficient lighting technologies and control strategies
available.
Always design the lighting system before
designing the HVAC system.
The first step in lighting design is to determine the visual
needs of the space and identify what type of lighting to
use. Lighting types are divided into four categories:
1. Ambient lighting typically used for circulation
and general lighting to give a sense of space.
Design ambient lighting systems before designing
systems to accommodate the other lighting types.
2. Task lighting used where clearly defined light­
ing levels are required to complete detailed work,
such as paperwork, reading, or bench-top experi­
ments.
3. Accent lighting used for architectural purposes
to add emphasis or focus to a space or to highlight
a display.
4. Emergency or egress lighting used to provide
a pathway for exiting a building if an emergency
arises.
Los Alamos National Laboratory Sustainable Design Guide
83
equipment options for minimizing these loads. Reducing
plug and process loads will decrease internal heat gains
from this equipment, reduce building cooling loads, and
decrease production of effluents from burning fossil
fuels to produce electricity to operate this equipment.
Finally, develop a controls strategy that will operate the
HVAC&L systems with the maximum comfort to the
occupants at the minimum cost. Metering and evalua­
tion is also important for providing continuous feed-
back for improvement.
Fluorescent lighting is the best type of lighting
for most applications at LANL (usually linear fluo­
rescent lamps). It can be easily controlled and
integrated with the daylighting design.
Linear fluorescent lamps are classified by tube
diameter, wattage, color rendering index (CRI),
and color temperature, where:

Tube diameter is measured in 1/8" increments
(e.g., the diameter of T-8 lamps is 1" and the
diameter of T-5 lamps is 5/8").

Wattage is the power required to operate the
lamp. The wattage is usually stamped on the
lamp itself or on the package in which the lamp
is shipped. Note that the lamp wattage is dif­
ferent from the system wattage, which includes
auxiliary equipment such as the ballasts.

CRI is the ratio of the light source to a stan­
dard reference source. A CRI of over 80 for a
fluorescent lamp is considered very good color
rendering, while some high-pressure sodium
(HPS) lamps have CRIs in the 20s.

Color temperature gives a general idea of the
visual color of the lamp (warm more red
2000 to 3000 K, or cool more blue 4000 K
and above), while color rendering is how accu­
rately a lamp renders colors in the environment.
Fluorescent Lighting Chapter 5
|
Lighting, HVAC, and Plumbing
Ambient Lighting
Ambient lighting systems can be easily integrated with
the available daylighting. In a well-designed building,
daylighting can offset most or all of the daytime ambi­
ent lighting loads. Use the following four steps to
design ambient lighting systems.
1. Define the daylighting zones. Evaluate the loca­
tion of the windows. Align the daylighting zones par­
allel to the windows with breaks at 5 feet, 10 feet,
and 20 feet away from the windows. Place zone
separations at corners where windows change ori­
entation. Also, carefully evaluate