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1. Introduction 
To VRF:
System 
Overview, 
Applications, 
& Savings 
Opportunities

2. System  System 
Overview Overview

3. What is VRF?
•
Zoning System
•
Two-Pipe / Three Pipe System
•
Packaged DDC Control
•
Operates as a Heat Pump
•
Simultaneous Cooling & Heating
•
Inverter Technology / Variable Speed
Compressor
•
Multiple Indoor Units – Up to 50 Indoor
Units Per System
•
Connected Diversity – Up to 150%
•
Variable Capacity Indoor Units
•
EMS / BMS Compatibility
•
High Turn Down Ratios – Below 10% In
Many Cases
V
ariable
R
efrigerant
F
low

4. INVERTER Technology
Changes electrical frequency from 60 Hz (line Power ) to a varying
range (10 Hertz to 110 Hertz – depending on the syst em)

5. INVERTER Technology
Time
Room Temperature
TAutomatically adjusts compressor speed to meet load
TSizing flexibility with variable capacity
TStrives to run long periods at lower speeds.
• Reduced / eliminated cyclic losses
TImproved temperature control
• No more minimum cycle timers – no temperature
overshoot.
VRF VRF
VRF
SETPOINT
CONVENTIONAL CONVENTIONAL

6. AHRI Standard 1230 –VRF HAS ARRIVED !
3.27 VRF Multi-Split System. A split system air-conditioner or heat
pump incorporating a single refrigerant circuit, wi th one or
more outdoor units, at least one variable speed com pressor or
an alternative compressor combination for varying t he capacity
of the system by three or more steps, multiple indo or fan coil
units, each of which is individually metered and in dividually
controlled by a proprietary control device and comm on
communications network. The system shall be capable of
operating either as an air conditioner or a heat pu mp. Variable
refrigerant flow implies three or more steps of con trol on
common, inter-connecting piping.

7. The Evolution VRF
Example (Mitsubishi City Multi):
Japan 20+ Years, Tried and Proven!
Europe 15+ Years, depending on the country
Latin America 10+ Years, from Mitsubishi US
Bermuda 10+ Years
USA since 2002!

8. Simultaneous Systems Components OUTDOOR
UNIT
Remote
Controllers
+
BC / Branch
CONTROLLER
+
INDOOR
UNITS
+
or
WATER-SOURCE UNIT

9. Typical Simultaneous 2-Pipe VRF System Layout

10. Changeover Systems Components
OUTDOOR
UNIT
CONTROLS
+
INDOOR
UNITS
+
or
WATER-SOURCE UNIT

11. Typical Changeover VRF Systems Layout
COOLING
HEATING

12. Power Supply
Controls Example
Central Controllers
Power Supply
TG-2000
LAN
Hub
TG-2000
PC
Control
Remote Controllers

13. Building Management System (BMS)
Hub
Ethernet
LonTalk
Central Controller
BACnet
Building Management Systems
May Be A
Hardware
Interface

14. Applications Applications
& System  & System 
Capabilities Capabilities

15. Target Commercial Applications
Buildings where
zoning is required
Applications where sound is important
Historic
Renovations
Multi-Story Office Buildings
Hotels
Banks
Universities
Churches

16. SEACOAST PROTECTION
Hospital Admin Areas /
MOB – Non Procedure
RESIDENTIAL
BANKS
Additional Applications

17. Building Use Occupant Load Solar Load
Cooling Diversity –3 Types

18. VRF Excels at Heat Recovery Applications !
Typical Winter Loads
Heat
CHILLER,
COOLING
TOWER, &
PUMPS
Heat
BOILER
& PUMPS
$
$
Why Spend
Money On
Both?
Heat

19. BTU/$ -VRF Makes Good Sense !

20. Diversity -Heating
Minimal Diversity Available !
Ambient Modification Charts
• Available capacity decreases
• Both outdoor and indoor units de-rated
• Defrost Operation
Evaluation of De-ratings Important!
• Use tools available from VRF manufacturer to
accurately access de-ratings.
Auxiliary Heating Changeover Point
• Try and maximize heat pump hours – depends on
climate.
Columbus Ohio: 90% of heating hours above 25 Deg F based on
Hourly Average Weather Data. Evaluation of De-ratings Important !
• Use tools available from VRF manufacturer to
accurately access de-ratings.

21. Typical Range Of Available VRF Systems
Air Cooled
6 – 24 Ton (Simultaneous)
6 – 30 Ton (Change Over)
208/230, 460 Volt – 3 Phase
62 dB(A) Operating Sound Level
Water Cooled
6 – 20 Ton (Simultaneous)
6 – 30 Ton (Change Over)
208/230, 460 Volt – 3 Phase
Single Phase 3, 4 Ton (Change Over)
208/230, 1 - Phase

22. Partial Backup capability with multiple / twinned units.
The remaining one or two units will perform backup operation
Twinned Units Typically Required above 12 Tons
Partial Back-up Operation

23. Typical Outdoor Temperature Operating Range
Cooling – Can be extended with low ambient options (as low as -10 F)
-20
-4
-15
5
-10
14
-5
23
0
32
5
41
10
50
15
59
20
68
25
77
30
86
35
95
40
104
45
113
50
122
o
CDB
o
FDB
Heating
-24
-13
-13
-10
-20
-4
-15
5
-10
14
-5
23
0
32
5
41
10
50
15
59
20
68
25
77
30
86
35
95
40
104
o
CWB
o
FWB
Outdoor Temperature
Outdoor Temperature
115 F 23 F Single Phase – Air Cooled
23 F Simultaneous & Changeover – Air Cooled 115 F 23 F 115 F Extended Heat Capacity – Air Cooled
Single Phase – Air Cooled 0 F 60 F
Simultaneous & Changeover – Air Cooled -4 F 60 F
Extended Heat Capacity – Air Cooled60 F -13 F
NOT your typical Heat Pump Technology !

24. Extended Range Heat Pump Technology
70
o
F
entering
air temp
Not Your Typical Heat Pump !
0
20
40
60
80
100
120
-13 -4 5 17 25 30 35 40 47
Outdoor Temperature
o
FWB
% Heating Capacity
Extended Rang VRF
Standard VRF
100%
87%
75%
50%

25. Water-source VRF Units -Changeover Systems
Heat Recovery In Water Loop Only Heat Recovery In Water Loop Only
Water Circuit
System System
““
AA
””
in in
COOLING Mode COOLING Mode
(refrigerant (refrigerant
absorbing heat) absorbing heat)
Heat is
recovered
between the
units within
the water
loop
System System
““
BB
””
in in
HEATING Mode HEATING Mode
(refrigerant (refrigerant
discharging heat) discharging heat)
PQHY
Unit “A”
PQHY
Unit “B”
Cooling
Cooling
Cooling
Cooling
Heating
Heating
Heating
Heating

26. Water-source VRF Units –Simultaneous Systems
Heat Recovery In Two Locations
Indoor units Indoor units
Water circuit
Indoor units Indoor units
Heat recovery
Heat recovery
Cooling
Cooling
Cooling
Cooling
Heating
Heating
Heating
Heating
PQRY
PQRY
Heat is
recovered
between the
units within
the water
loop

27. Directly
Coupled to a
Lake or Pond
Open
Loop
NO
NO
Directly
Coupled to
Ground water
Open
Loop
Water-source VRF Units
Installations not allowed!
NO

28. Heat Exchanger
Isolation
Coupled to a Lake or Pond
Closed
Loop
HX
YES
Heat Exchanger
Isolation
Coupled to Ground Water
Closed
Loop
HX
YES
Water-source VRF Units Installations allowed
YES

29. Closed Piping
Loop
Coupled to Earth
Vertical
Closed
Loop YES
Closed Piping Loop
Coupled to Earth
Horizontal
Closed
Loop
YES
Water-source VRF Units Installations allowed
YES

30. Indoor Indoor
Equipment  Equipment  Flexibility Flexibility

31. Indoor Unit Flexibility
Multiple styles ranging from 6,000 to 96,000 Btu/h

Typically single phase below 6 Nominal Tons

Linear Expansion Valve

Variable Capacity Operation

Mode:
Fan,Fan,
Cool, Cool,
Dry, Dry,
AutoAuto
,
HeatHeat

Built in or accessory condensate removal options from f actory.

Typical Ventilation Air options –most models

Average operating sound levels around 35 dB(A) +/-

32. Wall Mounted 6 - 30 MBtu/h Ceiling Suspended 15 - 36 MBtu/h Floor Standing
6 – 24
MBtu/h
Product ReviewCITY MULTI VRF
Indoor Unit Flexibility

33. 4 –Way Large Cassette 12 - 36 MBtu/h 4 -Way Small Cassette
8 – 15 Mbtu/h
One Way Cassette
6 – 15 Mbtu/h
Product ReviewCITY MULTI VRF
Indoor Unit Flexibility

34. Enhanced air distribution by
independent vane settings
Independent Vane Control
Vanes can be independently adjusted
by a remote controller
Fixed
HorizontalAir Vanes –4 Way Cassettes

35. Medium Static
6 – 54 Mbth/h
High Static
15 – 96 Mbtu/h
Low Profile
15 – 24 Mbtu/h
Vertical Ducted
12 – 54 Mbtu/h
Product ReviewCITY MULTI VRF
Indoor Unit Flexibility –Ducted Units

36. Recessed Unit –St. Xavier Cathedral

37. Refrigerant  Refrigerant 
Piping &  Piping & 
Refrigerant  Refrigerant 
Leakage Leakage

38. Refrigerant Piping Flexibility –2 Pipe Example
393 ft.
984 ft.-
1640 ft.
3,280 ft. 1,804 ft.-2,460 ft. 1,804 ft.-2,625 ft. Total Piping Length
PIPING LENGTH`
Simultaneous
Air Cooled
2-Pipe
Simultaneous
Water Cooled
2-Pipe
Changeover
Air Cooled
2-Pipe
Changeover
Water Cooled
2-Pipe
Single
Phase Air
Cooled
Farthest Indoor unit 541 ft. 541 ft. 541 ft. 541 ft. 262 ft.
PIPING HEIGHT
Simultaneous Air
& Water Cooled
2-Pipe
Changeover Air &
Water Cooled
2-Pipe
Single
Phase Air
cooled
Outdoor Unit HIGHER than Indoor Unit164 ft.*98 ft.
Outdoor Unit LOWER than Indoor Unit 131 ft. 65 ft.
Indoor Unit to Any BC Controller 49 ft.
n/a
n/a

39. Two Pipe Example
•Soft Copper BC to IU
•Reducers possible at BC
•Soft Copper BC to IU
•Reducers possible at BC
12 indoor-unit system –Heat Recovery 12 indoor-unit system –Heat Recovery

40. Three Pipe Example
•Hard copper from OU to 
BS
•Reducer fittings
•Hard copper from OU to 
BS
•Reducer fittings
12 indoor-unit system –Heat Recovery 12 indoor-unit system –Heat Recovery

41. Refrigerant Leakage Concentration Levels
What is RCL?

Refrigerant Concentration Limit (RCL):
“the refrigerant
concentration limit, in air, determined in accordan ce with this
standard and intended to reduce the risks of acute toxicity
asphyxiation and flammability hazards in normally o ccupied,
enclosed spaces”

RCL typically expressed as lbs/1000 ft
3

42. Determination of RCL
Referenced Codes/Standards

International Mechanical Code
•Previously set RCL for R-410A at 10 lbs/MCF
•2009 Revisions raises
RCL to 25 lbs/MCF

ISO-5149
•ISO-5149 sets R-410A RCL as 18.7 lbs/MCF

ASHRAE 15-2007
•ASHRAE 15-2007 establishes the
R-410A RCL as 25lbs/MCF
through reference to ASHRAE 34.

43. Critical Concentration Calculation
RCL (R410A) = 25 lb./Mcf
Refrigerant Charge (Rc) of a P72 = 23 lbs 3 oz = 23 .1875 lbs
MAV = Minimum Applied Volume (cubic feet)
MAV = Rc/RCL
MAV = (23.1875 lbs)/(25 lbs/1000 cu ft)
MAV = 927.5 cu ft

44. Appropriate Solutions Option 1-Locate Equipment within larger space
•Ducted communicating spaces w/ no closure devices that restrict
airflow below 10% of peak airflow.
Option 2-Do not use equipment with refrigerant
Option 3-Increase room volume through the use of openings
•Door Undercuts, transfer ducts or grilles.
Option 1
Option 2
Option 3

45. •Inverter-driven
compressors /
part load
performance !
•Variable
capacity indoor
units !
•Extended Heat
Pump (Air to Air)
Capability !
•Simultaneous
cooling and
heating !
The Efficiencies from
“VRF System Effect”

46. Summary of Refrigerant Management
Refrigerant Concentration Limit is a tool to protect
the public

Informed and educated engineers can incorporate
necessary measures to meet the RCL.

R410A is of lowest toxicity and is NOT combustible.

47. Energy  Standards  Energy  Standards 
& Savings  & Savings 

48. AHRI 1230 & IEER

AHRI Standard 1230 created a testing standard for V RF equipment above 65,000
Btu/h (below 65,000 Btu/h continues to be rated i n accordance with AHRI Standard
210/240-2008)

On January 1st, 2010, IEER superseded IPLV as the testing standard for VRF
equipment above 65,000 Btu/h

Unlike testing VRF for IPLV (according to AHRI Stan dard 210/240), testing for IEER
involves actual testing at part load conditions and assigning weighted values to each
test point

Testing VRF for IEER involves testing at four fixed conditions: 100%, 75%,
50%, & 25% load. The equipment is still not allowed to vary compressor speed
and indoor unit capacity to meet a varying load as it was designed to do

Simultaneous Heating and Cooling Efficiency (Not Yet Tested)

SCHE = (Heating Capacity (Btu/h) + Cooling Capacity (Btu/h)) / Total System Power
Input (Watts)

49. ASHRAE 90.1-2010 VRF Benchmarks

50. ASHRAE 90.1-2010 VRF Benchmarks

51. Energy Star Requirements

52. Energy Modeling
EnergyPro
Version 5.0
Accepted by the USGBC for
Compliance with Energy and
Atmosphere Credit 1

53. Sample Building in Part Load: OA Temp 50
o
F
Simultaneous Load:
Cooling: 27000 BTU Heating: 21000 BTU
3000 BTU
6000 BTU
3000 BTU
3000 BTU
3000 BTU
Elect
Janitor
Break Room
Lobby/
Waiting Room
Conference
Room
Office #1 Office #2
Cubicle Area
Open Work
Room
6000 BTU
12000 BTU
6000 BTU
3000 BTU
3000 BTU
Women Men
PURY-P72
What Makes Energy Pro Different

54. What Makes Energy Pro Different
Cooling Power Input PURY-P72
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
0 12000 24000 36000 48000 60000 72000 84000
System Load BTUH
Power Input KW
72,000 BTUH
6.48 KW
27,000 BTUH
2.38 KW

55. What Makes Energy Pro Different
Outdoor Temperature Power Input Correction
(For a 68 Indoor WB Temperature)
1.5000
1.6000
1.7000
1.8000
1.9000
2.0000
2.1000
2.2000
2.3000
2.4000
0 10 20 30 40 50 60 70 80 90 100
OA Temperature FDB
P o w e r Inp ut K W
2.38 KW at 95
o
F
1.87 KW at 50
o
F

56. What does this mean
Getting 27,000 BTUH of cooling and 21,000 BTUH of
heating, while providing only 1.87 KW to the outdoo r
unit.

This savings cannot be realized without the ability to
model simultaneous heating and cooling. For this scenario,
Calculated Efficiency of 25.7 EER

57. School Energy Modeling Results
School--Percentage Energy Cost Savings V/S Comparable Systems
0% 4% 7% 11% 14% 18% 21% 25% 28% 32%
Atlanta
Miami
Boston
NYC
Chicago
Dallas
LA
Seattle
Location
Energy Savings
CM v/s VAV CM v/s 4 Pipe CM v/s WSHP

58. Office Building Energy Modeling Results
Percentage Energy Savings V/S Comparable Systems
0% 4% 7% 11% 14% 18% 21% 25%
Atlanta
Miami
Boston
NYC
Chicago
Dallas
LA
Seattle
Location
Energy Savings
CM v/s 4 Pipe CM v/s VAV CM v/s WSHP

59. Questions & Answers
Thank You For Having Us
Today!
We Are Here To Help Make Your VRF
Projects Successful !