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6/8/2016
1
Top secretSecret
Internal use onlyPublic
VRV to AHU connectionApplication guide
6/8/2016
2
Title - Internal use only3
BasicsIn this chapter we will learn about:• How VRV can be useful for AHU air treatment
• What are the benefits of this application
• What possibilities do you have
01.
Title - Internal use only4
THE BASICS
Supply AirInlet Air
Adjustment damper
Filter section
Treatment section
Fan section
View: SECTION
Post-heating section
Humidification section
Drop separator
Here we can apply VRV for cooling or heating the supplied
air in DX coils.
Where to use VRV?
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Title - Internal use only5
THE BASICS
What do you need to use VRV for cooling and heating the air in the AHU?
R410A gas
R410A liquid
communication Thermistors
EXV control
1. Outdoor unit(s)
(work as CCU)
3. Expansion valve set
(refrigerant flow and pressure control in DX coil)
2. Air Handling Unit with properly
designed DX coils (Daikin or 3rd Party)
4. Control box (controls the expansion
valve set and outdoor unit(s) capacity
2a (optional). Air Handling Unit
control box (Daikin or 3rd Party)
5. Local or central remote controllers (in some cases)
Title - Internal use only6
THE BASICS
What are the benefits?
1) Immediate Cooling and Heating under any ambient or room conditions → less heat transfer losses, fast and accurate response to load changes → better comfort and less energy consumption compared to water cooling/heating coils coupled with chillers.
2) Better management of load for medium size spaces due to VRV technologies. • Total solution: AHU can work together with other VRV indoor units in same system • Extended operating range • Accurate temperature control due to inverter capacity management• Quick switchover between cooling & heating.→ better comfort and wider possibilities compared to water systems and ON/OFF CCUs.
3) Top Energy Efficiency and reliability• Energy saving due to inverter technology• No inrush current• Less start/stop cycles, longer compressors lifetime• VRV IV: VRT control is furthermore increasing seasonal efficiency• VRV IV: numerous settings targeting either higher efficiency or quick response.→ lower running costs
4) Continuous Heating with VRV IV dedicated heat pump range:• Avoid Cold drafts during defrost cycle• Fresh air can be continuously supplied at comfortable temperatures→ better comfort
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Title - Internal use only7
THE BASICS
What are the configuration possibilities?
DX coil + ERQ outdoor unit
ERQ (up to 25 kW)
•Pair combination (1 outdoor+ 1 DX kit)
•Heat pump
VRV IV Heat pump (up to 150 kW on Multi combination)
•Pair combination(1 outdoor + 1 DX kit)
•Multi combination: (1 outdoor+ several DX kits):
- AHU+AHU
- AHU+VRV IU (only return air control is available in this case)
Supply air temperature controlor
Return air temperature control
VRV IV Heat recovery (up to 150 kW on Multi combination)
•Multi combination:
- AHU+VRV IU
DX coils + VRV IV outdoor unit
Supply air temperature controlor
Return air temperature controlReturn air temperature control
Title - Internal use only8
THE BASICS
What are the temperature control possibilities?
Td (discharge air temperature
sensor)
Tr (room air temperature sensor)
Return Air Supply Air
Ts (supply air temperature
sensor)
Te (evaporator temperature
sensor)
DDC controller(AHU’s own
controller, collecting data from sensors
and forming capacity demand signal)
X: Control of supply or return air temperature ( uses Td, Ts or Tr- all field supplied sensors) with external controller (DDC) using an un-proportional 0~10 V algorithm for capacity control
Y: Control of evaporating/condensing temperature, indirect room temperature control (uses Te- Daikin supplied) with 3rd party thermostat and Daikin controller BRC1D52 or BRC1E52A/B used for field settings and error indication
Z: Control of supply or return air temperature (uses Ts or Tr- Daikin or field supplied sensors) with Daikin controller BRC1D52 or BRC1E52A/B used for control, field settings and error indication
W: Control of supply or return air temperature (uses Td, Ts or Tr- all field supplied sensors) with external controller (DDC) using a proportional 0~10 V algorithm for capacity control
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Title - Internal use only9
Selection and build-upIn this chapter we will learn about:• How the selection process goes
• What components do you need in each case
• What are the restrictions and limitations
02.
Title - Internal use only10
LINE-UP (WHAT DO YOU HAVE TO SELECT FROM)
1. Outdoor unitsThe following ranges are suitable:• ERQ (11-28 kW);• VRV IV HP RXYQ-T/RYYQ/T/RYMQ-T(22-150 kW)• VRV IV HR REYQ-T (22-150 kW)• Water Cooled VRV RWEYQ-T (22-84 kW)
2. Control boxes:• EKEQFCBA (for all types of VRV and ERQ)• EKEQDCBA (for ERQ only)• EKEQMCBA (for VRV only)
Model EKEXV50 EKEXV63 EKEXV80 EKEXV100 EKEXV125 EKEXV140 EKEXV200 EKEXV250 EKEXV400 EKEXV500
Allowedcoil
capacity, kW
(cooling)
5,0-6,2 6,3-7,8 7,9-9,9 10,0-12,3 12,4-15,4 15,5-17,6 17,7-24,6 24,7-30,8 35,4-49,5 49,6-61,6
Allowed coil
capacity,kW
(heating)
5,6-7,0 7,1-8,8 8,9-11,1 11,2-13,8 13,9-17,3 17,4-19,8 19,9-27,7 27,8-34,7 39,8-55,0 55,1-69,3
4. Expansion valves sets:
3. Air handling units:
AHU
Daikin 3rd Party
Easy (500-33000 m3/h)
Professional (750-144000 m3/h)
Energy (750-100000 m3/h)
Modular (500-25000 m3/h)
Integrated Daikin DDC controllers
possible
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Title - Internal use only11
SELECTION PROCESS
Step 1. Calculate the required coil capacity, determine coil parameters and select expansion valves
Air flow
On coil air temperature and humidity (summer/wi
nter)
Off coil air temperature (summer/wi
nter)
Coil capacity (cooling/heating)
Coil parameters
Volume
# of circuits
# and type of expansion valve sets
AHU selection software
VRV selection software
At this stage consider limitations (refer to EXV data books):• Allowed MIN and MAX cooling capacity for EXV sets• Allowed MIN and MAX heating capacity for EXV sets
AHU software suggests 65 kW single circuit coil. Is it OK?
No, max. capacity for single circuit is 61,6 kW. You need to split your coil.
AHU software suggests 6 kW double circuit coil (3+3 kW). Is it OK?
No, min. capacity for single circuit is 5 kW. You need to go to 1 circuit coil.
Title - Internal use only12
SELECTION PROCESS
Step 2. Determine your system configuration and select control box(es) and outdoor units
System configuration
Pair
VRV
ERQ
EKEQDCB(A)
EKEQFCB(A)
Multi
Single AHU with multi-circuit coil
Several AHUs
AHUs and VRV indoor
units
EKEQFCB(A)
EKEQMCB
Based on selected EXV capacity (@
step 1), if ≤28 kW
Based on selected EXV capacity (@
step 1), if > 28 kWSelect the
outdoor unit based on total connected EXV
capacity
Select the outdoor unit
based on total connected EXV
capacity
X/Y Control
X/Y/W Control
X/Y/W Control
Z Control
VRV selection software
EKEQFCB(A)X/Y/W Control
Z Control
It is important to understand how temperature control modes work to select the most appropriate for your
project!
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Title - Internal use only13
TEMPERATURE CONTROL MODES
X-Control – how it works?
Measurements of:• Tr or• Ts or• Td
0-10 V signal
Capacity step signal to the outdoor unit:• Level 1• Level 2• Level 3• Level 4• Level 5
ΔT=0 +ΔTmax-ΔTmax
V - voltage input to the control box
ΔT0V
5V
10V
ΔT – is the difference between the set point and the
temperature measured by the sensor;
ΔTmax – maximum allowed difference between the
set point and the temperature measured by the sensor, 2-50C – is programmed during commissioning.
DDC controller EKEQF control box
Voltage from the DDC controller is linear function of ΔT:
V =5
∆Tmax× ∆T + 5
Depending on the input voltage, EKEQ control box will send to the outdoor unit the capacity step signal:
EXV is controlled to provide certain Te (evaporation
temperature)
Capacity level Cooling Heating
Level 1 Capacity ↓↓ Capacity ↑↑
Level 2 Capacity ↓ Capacity ↑
Level 3 Keep current capacity
Level 4 Capacity ↑ Capacity ↓
Level 5 Capacity ↑↑ Capacity ↓↓
Title - Internal use only14
TEMPERATURE CONTROL MODES
X-Control – how it works (continued)?
Measurements of:• Tr or• Ts or• Td
0-10 V signal
Capacity step signal to the outdoor unit:• Level 1• Level 2• Level 3• Level 4• Level 5
DDC controller EKEQF control box
EXV is controlled to provide certain Te (evaporation
temperature)
Level 10V
1,8V
3,8V
6,8V
8,8V
Level 2
Level 3
Level 4
Level 5
If the voltage from DDC is increasing:
Level 10V
1,2V
3,2V
6,2V
8,2V
Level 2
Level 3
Level 4
Level 5
If the voltage from DDC is decreasing:
The EKEQ controller switches between capacity levels like this:
10V 10V
What are the benefits? When to use this type of control? It is expensive to buy and setup…
The benefits are:• Fast response to load variation
(capacity is immediately changed as a function of measured temperature)
• Precise temperature controlYou may use this type of control in comfort sensitive applications. This is also used by default in Daikin AHU controls.
6/8/2016
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Title - Internal use only15
TEMPERATURE CONTROL MODES
Y-Control – how it works?
3rd Party Thermostat EKEQF control box
Outdoor unit
EKEXV EV box
Measures room temperature, sends ON/OFF signal to control box when set point is reached
ON/OFF signal
Settings, incl. Te/Tc
BRC1(D,E)
Used to make the necessary settings
Te/Tc control
Te/Tc control
• Evaporation and condensing temperatures (for cooling and heating modes respectively) are fixed, by field settings on remote controller:• Te = 5…120C (default 80C)• Tc = 43…490C (default 460C)
• The system will only deviate from set Te/Tc in case of safe modes activation
How does the system work?
What are the benefits? When to use this type of control? Looks very easy and cheap, what are the drawbacks?
• Cheap and simple solution (no additional DDC controller required)
• No direct temperature control. Room temperature may fluctuate significantly
You may use this type of control in comfort insensitive applications with constant cooling/heating load (technical rooms).
Title - Internal use only16
TEMPERATURE CONTROL MODES
Measurements of:• Tr or• Ts or• Td
0-10 V signal
Capacity step signal to the outdoor unit:• Level 1 = 0% capacity• Level 2 = 40% capacity• Level 3 = 60% capacity• Level 4 = 80% capacity• Level 5 = 100% capacity
DDC controller EKEQF control box
EXV is controlled to provide certain Te (evaporation
temperature)W-Control – how it works?
DDC outputs the voltage signal proportional to ΔT
(same as X-control)
𝑉 =∆𝑇
∆𝑇𝑚𝑎𝑥× 10
EKEQ box selects the capacity step and sets it by fixing the
Te/Tc at certain level (not direct % of capacity!)
The system tries to adjust the compressor speed to reach ΔT=0 with this Te/Tc
ΔT measurement
Capacity level
Voltage from DDC controller
Te setting (cooling)
Tc setting (heating)
Approx. % of capacity
Level 1 0,8 - - 0 (OFF)
Level 2 2,5 13,50C 310C 40
Level 3 5 110C 360C 60
Level 4 7,5 8,50C 410C 80
Level 5 9,2 60C 460C 100
We can (though indirectly) set the % of system capacity by means of 0-10 V signal.Most of the AHU controllers available in the market are suitable for this without any additional programming.
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Title - Internal use only17
TEMPERATURE CONTROL MODES
W-Control – how it works (continued)?
Measurements of:• Tr or• Ts or• Td
0-10 V signal
Capacity step signal to the outdoor unit:• Level 1 = 0% capacity• Level 2 = 40% capacity• Level 3 = 60% capacity• Level 4 = 80% capacity• Level 5 = 100% capacity
DDC controller EKEQF control box
EXV is controlled to provide certain Te (evaporation
temperature)
What are the benefits? When to use this type of control? Looks very similar
to X-control…
The benefits are:• Direct temperature control (capacity is changed as a function of measured temperature)• Most standard AHU controllers are suitable without additional programming• Due to variable refrigerant temperature no cold/hot draftsBut:• Slower response to load variation -> room temperature fluctuation, less accurate temperature control
(compared to X-Control), because of longer control sequence:
Measure Adjust capacity Measure Set target T Reach target TAdjust capacity
(fine tune)
X-Control W-Control
You can use this type of control to combine VRV/ERQ with 3rd
party AHUs, if you need supply temperature control
Title - Internal use only18
TEMPERATURE CONTROL MODES
Z-control – how it works?
This is the only possible mode in multi-AHU or VRV indoors + AHU configurations.
Daikin or 3rd Party Thermistor
Outdoor unit
EKEXV EV box
Measures room temperature, sends ON/OFF signal to control box when set point is reached
Room or supply air temperature
information Settings, incl. Tset (set point temperature)
BRC1(D,E)
Used to control the system and make the necessary settings
EXV control (depending on Tset-Tr(or Ts)
Capacity command
Superheat/subcool information
EKEQM
Works the same as ‘normal’ VRV indoor unit (cooling and heating):• Tr(Ts)-Tset ↑ -> EXV opening ↑,
outdoor unit capacity ↑(superheat/subcool decrease) -> more refrigerant flow, more capacity.
• Tr(Ts)-Tset ↓ -> EXV opening ↓, outdoor unit capacity ↓(superheat/subcool increase) -> less refrigerant flow, less capacity.
What are the benefits? When to use this type of control?
• Cheap and simple solution, no need to use the additional controllers, etc.
• You can combine VRV units and AHUs in one system, or connect several AHUs to 1 outdoor unit.
• No supply temperature control, comfort conditions can be affected by hot/cold drafts
You can use this mode if there is no particular supply temperature required or you want to combine VRV indoors and AHUs in one system.
6/8/2016
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Title - Internal use only19
NECESSARY COMPONENTS AND LIMITATIONS
ERQ/VRV IV Heat Pump 8 and 10 HP
EKEQ*Control Box
EKEXVExpansion Valve
R410A gas
R410A liquid
communication
Thermistors
EXV control Air Handling Unit (AHU)
EKEXV class
63
80
100
125
140
200
250
• To control the temperature of the air leaving or returning to the AHU, by means of an external DDC device (X and W control)
• To control indirectly the room air temperatureby fixing Te or Tc (Y control)
• To control the temperature of the returning air to AHU by means of a Daikin controller (Z control)
EKEQFCBA EKEQD
What do I need for pair application (coil capacity ≤ 25 kW)?
Min 5 m, max. 50 mM
ax +
/-3
0 m
Max. 5 m
Max
+/-
5 m
0-10 V
DDC Controller
Title - Internal use only20
NECESSARY COMPONENTS AND LIMITATIONS
What do I need for pair application (coil capacity > 25 kW)?
VRV IV Heat Pump CH/Non-CHWater cooled VRV
EKEQ*Control Box
EKEXVExpansion Valve
R410A gas
R410A liquid
communication
Thermistors
EXV control Air Handling Unit (AHU)
• To control the temperature of the air leaving or returning to the AHU, by means of an external DDC device (X and W control)
• To control indirectly the room air temperatureby fixing Te or Tc (Y control)
EKEQFCBA
Min 5 m, max. 50 m
Max
+/-
30 m
Max. 5 m
Max
+/-
5 m
0-10 V
DDC Controller
EKEXVclass
200
250
400
500
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Title - Internal use only21
NECESSARY COMPONENTS AND LIMITATIONS
What do I need for pair application (coil capacity more than 50 kW, multi-circuit)?
Supply air (or return air) temperature control (X, Y, W)
F1F2 F1F2F1F2
• Max 3 DX kits/AHU• Connection ratio between 90~110%• Temperature control by DDC (0-10 V signal)
EKEQFCBA EKEQFCBA EKEQFCBA
Thermistors
EXV control
0-10 V
EKEXV class
63
80
100
125
140
200
250
400
500
Interlaced coil (max. 3 circuits). Max. capacity =
50 kW x 3 = 150 kW
DDC Controller
EXV control EXV control
Piping length limitations are the same as for single circuit coils:• OU → (each) EXV kit = 5..50 m• EXV kit → AHU = 5 m max.• Level difference between OU and AHU = 30 m max.
VRV IV Heat Pump CH/Non-CHWater cooled VRV
22
NECESSARY COMPONENTS AND LIMITATIONS
Only return air temperature control (Z) is possible. Like VRV indoor units.
F1F2
F1F2
• Connection ratio is limited between90~110%
• Unlimited number of DX kits/AHUs within connection ratio
• Control by iTM II and/or local Daikin controllers (MANDATORY) EKEQMCBA
EKEQMCBA
What do I need for multi application (several AHUs in one circuit)?BRC1(D,E)
BRC1(D,E)
EKEXV
EKEXV
EKEXV class
63
80
100
125
140
200
250
400
500
AHU DX coils. Number of circuits is theoretically
unlimited.
Piping length limitations:• EXV kit → AHU = 5 m max.• The rest are the same as for “normal” VRV
application (check VRV data book/installation manual)
VRV IV Heat Pump
CH/Non-CHWater
cooled VRV
P1P2
P1P2
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Title - Internal use only23
NECESSARY COMPONENTS AND LIMITATIONS
Only return air temperature control
(Z) is possible.
F1F2F1F2
F1F2F1F2
Conditions:• Unlimited DX kits/AHUs (within connection
ratio)• Connection ratio between 50~110%• VRV indoors should be min 50% ratio• Control by iTM II and/or individual wired
remote controllers (MANDATORY)
EKEQMCBA
EKEXV
VRV IU VRV IU VRV IU
P1P2 P1P2 P1P2
P1P2EXV control
BRC1(D,E) BRC1(D,E) BRC1(D,E)
AHU DX coil (theoretically unlimited number of circuits)
BRC1(D,E)
VRV IV Heat Pump CH/Non-CHWater cooled VRVVRV IV Heat Recovery
• VRV Indoors are mandatory in this case!
• Hydrobox connection is not possible!
Piping length limitations:• EXV kit → AHU = 5 m max.• The rest are the same as for “normal” VRV application (check VRV data book/installation manual)
What do I need for multi application (AHUs and VRV indoors in one circuit)?
24
NECESSARY COMPONENTS AND LIMITATIONS
What other possibilities do I have?
EKEXVEKEQMCBA
EKEXVEKEQMCBA
EKEXVEKEQMCBA
DX Kit 1
DX Kit 2
DX Kit N
DX
Outdoor Only Z-Control
If for some reason you need to work with more than 3-circuit coil with one outdoor unit, it is possible, but only in Z control mode.
EKEXVEKEQMCBA
EKEXVEKEQMCBA
EKEXVEKEQMCBA
DX Kit 1
DX Kit 2
DX Kit N
DX
Outdoor 1
Outdoor N
Only Z-Control
You can also connect several outdoor units to 1 multi-circuit coil, but only in Z control mode. Thus you can obtain theoretically unlimited capacity.
Coil (multi-circuit)
Coil (multi-circuit)
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Title - Internal use only25
COIL REQUIREMENTS
How to select DX coil properly? Is the coil selected by AHU selection software suitable for VRV application?
AHU DX coils Single circuitNo special requirements
Multi-circuit
With face control With row control Interlaced
Circuit 1
Circuit 2
Circuit 1
Circuit 2
Circuit 1
Circuit 2
Problems:• Temperature stratification at partial
load -> comfort issues
Benefits:• Simple construction, cheap
Problems:• Not possible to reach coil capacity
balance -> reliability issues
Benefits:• Simple construction, cheap, compact
Problems:• Complex construction
Benefits:• Even leaving air temperature• Coil capacity balanced
Only this solution is allowed for multi-circuit coils application!
Capacity ≤ 50 kWYES
NO
All these coil types you may get from AHU selection software
Thank you