Sustainable Design for Laboratories
Barry Barnet PE
PE, LEED AP
Issue
• Commercial buildings use a lot of electric power
and fossil fuel
• Lab buildings can use 10 times or more energy
than office buildings
Lab Building Energy Usage
• Higher plug loads than office buildings
• Air-handling systems with 100% outside air (no
recirculation)
• Higher air change rates per hour (ACH)
Design Variations: Traditional Strategy
(In accordance with ASHRAE 90.1)
System 1 (Base System)
• Constant volume (CAV) with enthalpy wheel
• Supply air temperature re-set during unoccupied hours
System 1 ( 2 – Position)
• Reduce flow during unoccupied hours
System 2 (VAV)
• Use
U variable
i bl air
i volume
l
(VAV) with
ith enthalpy
th l wheel
h l
• Relationship between max cooling CFM and minimum ACH/make-up
determines effectiveness of VAV system.
Design Variations: Sustainable Strategies
(In accordance with ASHRAE 90.1)
System 3 (Separated Cooling & Ventilation Systems)
• Bring in outside air to “ventilate and make-up”, but not to “cool” (ie:
separate cooling from ventilation)
• Use supplemental devices to “cool”
cool (chilled beams or fan coil units)
• Use dual energy recovery to produce “ventilation and make-up” air
(utilizing total and sensible wheels)
• Consider VAV for “ventilation and make-up air”
Room by Room Calculation for Peak CFM (Typical Labs)
• Cooling load from equipment
• Make-up for hood exhaust
• Air
Ai Ch
Change requirement
i
t (6-12
(6 12 ACH minimum)
i i
)
System 3 - Typical Reductions in Air-Handling System Size
Traditional Design
Dual Energy
Recovery with
Chilled Beams
Test Model
2.1 CFM/SF
14 ACH
0.9 – 1.8 CFM/SF
6 – 12 ACH
NJEDA
Advance Care
1.8 CFM/SF
12 ACH
C
0.9 CFM/SF
6 ACH
C
50%
Vermont Forensics
2.6 CFM/SF
17.3 ACH
1.9 CFM/SF
12.7 ACH
20%
Project “Y”
3.0
3
0 CFM/SF
20 ACH
2.0
2
0 CFM/SF
13.3 ACH
33%
Project “Z”
(8 A/C Minimum)
2.0 CFM/SF
12 9 ACH
12.9
1.5 CFM/SF
9 7 ACH
9.7
25%
Vermont Forensics: 35,000 SF of Lab in New England
Project “Y”: 60,000 SF of Lab in Mid Atlantic Region
Project “Z”: 45
45,000
000 SF of Lab in North Atlantic Region
Reduction in Size of
air Handling System
63% - 15%
System 3 – Separated Cooling & Ventilation Systems
Active Chilled Beam Schematic (Cooling)
68°F Primary “Neutral” Air
From Air Handling
g System
y
Primary air duct
Induction nozzle
59°F
Cooling
Water
Ceiling
Chilled Beam coils
Supply to
room
Supply to
room
Air Induced
into Beam
from Room
6 ft. To 10 ft. long x 2 ft. wide x 7 Inches Deep
System 3 – Separated Cooling & Ventilation Systems
Hood Exhaust
Dual Air to Air Energy Recovery (Ventilation)
Exhaust
“Neutral”
Neutral
Air Supply
Supply
Air
Air terminal
units
Pre-Heat
Coil
71 DB
65 WB
On
O
52 DB
51.5 WB
On
O
68
On
O
Off
O
68 DB
90 DB
M h i l
Mechanical
Refrigeration
Coil
Heating
Coil
To Other
Spaces
97 DB
79 WB
97 DB
79 WB
Primary
Air
Cooling
Water
Exhaust
Grilles
55 DB
Off
O
75 DB
Sensible
Wheel
Typical
Space
Suppl.
Air
Supplies
Active Chilled Beam
Chilled
Water
Total
Wheel
Outside Air
System 3 – Typical Room Ceiling Plan (w/ Chilled Beams)
Chilled
Beams
Suppl. Air
Supplies
Pendant
Lights
Exhaust
G ill
Grilles
NJEDA Tech IV
NJEDA Tech IV
Test Model – Located in Northeast U.S.
10,000 SF
S Lab ((Eight lab areas on perimeter, one lab area on interior))
Assumptions:
• 9 W/SF power, 1.5 W/SF of lighting, 6 ACH minimum occupied, 4 ACH
minimum
i i
unoccupied
i d
• Five 6’-0” fume hoods in load driven example
• Occupied 7AM to 7PM, Indoor summer 75°F, Indoor winter 70°F
• Unoccupied 7PM to 7AM, Indoor summer 78°F, Indoor winter 65°F
• Diversity on L&E: 50% occupied, 25% during normal occupied hours on
weekend/holiday, 10% unoccupied
• Diversity on People: 100% occupied, 25% during normal occupied hours
on weekend/holiday, 10% unoccupied
• Diversity on Hoods: 60% during occupied hours (ie: 40%reduction in airfl )
flow)
• Ventilation criteria: 100% outside air
Test Model: 10,000 sf Laboratory Space
70’
25 % Glass
1
2
3
8
9
4
7
6
5
25 % Glass
143’
Simulation Results – Annual Energy - Load/ACH Driven
SYSTEM
MIN
ACH
(occ.)
MIN
CFM
(occ.)
MAX
CFM
COOLING
MBTU
PRE-HEAT
MBTU
RE-HEAT
MBTU
FAN
MBTU
TOTAL
MBTU
% ENERGY
USAGE
1
1
CAV
2POS
21,000
21
000
21,000
21,000
21
000
21,000
1,881,000
1
881 000
1,601,000
54,900
54
900
53,100
729,000
729
000
712,500
1,300,000
1
300 000
876,400
3,964,900
3
964 900
3,243,000
100
82
2
2
2
2
6
8
10
12
9,000
12,000
15,000
18,000
21,000
21,000
21,000
21,000
1,415,500
1,461,800
1,508,200
1,554,600
38,200
41,900
45,600
49,400
510,800
561,200
611,600
662,000
674,500
724,900
775,400
825,900
2,638,900
2,789,900
2,940,900
3,092,000
67
70
74
78
3
3
3
3
6
8
10
12
9,000
9
000
12,000
15,000
18,000
9,000
9
000
12,000
15,000
18,000
1,628,400
1
628 400
1,705,400
1,782,400
1,859,400
48,400
48
400
60,000
71,600
83,200
0
0
0
0
479,400
479
400
581,500
683,600
785,700
2,156,200
2
156 200
2,346,900
2,537,600
2,728,300
54
59
64
69
Notes:
1. All three systems utilize energy recovery with wheel (or wheels)
2. Unoccupied set-back to 4 ACH (6,000 CFM) except for system 1 CAV
Simulation Results: Load/ACH Driven Example
100
System 1
(CAV)
% ENE
ERGY USA
AGE
90
80
System 1 (2 – position)
70
System 2
(VAV)
60
System 3
(Beams)
50
6 ACH
10 ACH
12 ACH
8 ACH
MINIMUM REQ’D OCCUPIED VENTILATON
Simulation Results – Annual Energy - Hood Driven
SYSTEM
HOOD
DIVERSITY
AVG
CFM
MAX
CFM
COOLING
MBTU
PRE-HEAT
MBTU
RE-HEAT
MBTU
FAN
MBTU
TOTAL
MBTU
% ENERGY
USAGE
1
1
2
3
CAV
2-POS.
60%
60%
30,000
30,000
18,000
18,000
30,000
30,000
30,000
30,000
3,149,000
2,826,000
1,554,600
1,859,400
820,000
755,600
49,400
83,200
1,358,000
1,292,600
662,000
0
1,604,000
1,211,880
825,900
785,800
6,931,000
6,086,140
3,092,000
2,728,400
100
84
43
39
Notes:
1 All three systems utilize energy recovery with wheel (or wheels)
1.
2. Unoccupied set-back to 4 ACH (9,000 CFM) except for system 1 CAV)
3. ACH = 20 at full design flow = 3.0 CFM/sf (assumed)
Simulation Results: Hood Driven Example
100
System 1
(CAV)
% ENERGY USA
AGE
90
System 1 (2 – position)
80
70
60
System 2 (VAV)
40
System 3 (Beams)
6 ACH
10 ACH
12 ACH
8 ACH
MINIMUM REQ
REQ’D
D OCCUPIED VENTILATON
Winter Water Economizer (Chilled Water)
C
Chiller(s)
( )
44o F
Primary
Pump(s)
60o F
60o F
Mixing
Valve
C
Secondary
Pump(s)
59o F
C
50o F
64o F
Air Handling Units
Chilled Beams
(Winter: Free Pre-heating of Ventilation)
(Winter: Free Cooling of Interior Areas)
Red = Summer
Blue = Winter (40o F and below)
Summer Waste-Heat Recovery (Condenser Water)
Cooling Towers
Condenser
Water Pump(s)
Chiller(s)
85o
95o
Heat
Ex.
82o
92o
Reheat Hot Water
in Summer
Red = Condenser Water
Blue = Reheat Hot Water
Chemical Free Water Treatment for Condenser Water
Combined with Storm Water Reclaim
Evaporation
Water Make-up
p
Domestic
Water
EPPWT
Cooling
g Towers
Storm Water &
Drips from
Cooling Coils
Vermont Forensics Project
Estimated annual reduction in HVAC energy:
50%
Estimated annual reduction in Total energy:
32%
Estimated annual savings in energy costs:
21%
Anticipated LEED points EA credit 1:
3-4
Conclusions
• An HVAC system with separated cooling and ventilation can offer
significant reduction in annual energy usage
• Innovative methods for water side economizing (winter) and waste heat
recovery (summer) provide additional energy savings
• Physical sizes of air handling units and ductwork are significantly reduced
• Chemical free water treatment and storm water reclaim can work together
to reduce harmful effects to environment and reduce water usage
QUESTIONS
This concludes the presentation for
Sustainable Design for Laboratories