Variable Refrigerant Flow Presented by: Benoit Chayer, ing. VRF Systems VRF : VARIABLE REFRIGERANT FLOW •  Technology introduced in Asia 25 years ago •  To minimize •  The losses found in conventional HVAC systems •  The footprint of the HVAC system •  Asia, Europe and South America are mature markets •  North American market is in full growth •  You can think of this as a big ductless split with multiple indoor heads. •  A VRF system can have up to 60 indoor units connected to a single outdoor unit VRF Market Share VAV system 4 Water source heat pump 5 VRF system •  Outdoor unit connected to multiple indoor units with refrigerant piping •  Outdoor unit installed on the roof or inside next to an outside wall (ducted air outlet) •  Electronic expansion valves open and close in every indoor unit to match the capacity •  Refrigerant flow is modulating depending on the load 6 VRF system VIDEO 7 Why refrigerant? •  Efficient way of moving energy in a building •  10x more energy per pound than water •  175x more energy per pound than air VRF what makes it different •  Variable speed fans for the outdoor units (INVERTER DC) •  Variable speed fan for the indoor units (BLDC) •  Electronic Expansion Valves (EEV) •  Variable speed compressors (INVERTER DC) •  Heat recovery between zones. Heat rejected from one zone can be used in another part of the building rather than being rejected to the outside. •  Minimal losses from ducts since most or all of the ductwork is eliminated. •  Eliminating ducts may also allow buildings to be designed with lower floor-to-floor heights, reducing construction costs. •  Comes in 2 formats •  Heat Pumps •  Heat recovery Heat Pump 2 pipe system : heating OR cooling mode just like a standard HP •  Indoor units connected to a Cooling Cooling Cooling Cooling ‘’main pipe’’ with a Y-branch •  Every zones in the same mode •  Each zone controls it’s own temperature set point Heat Recovery 3 pipe system : heating AND cooling at the same time •  3 pipes connected to a Cooling Heating Cooling Heating distribution box that controls the flow of suction gas and hot gas through the evaporator •  Each zone has the control over the mode AND temperature set point •  Energy transferred between zones / <*HR Unit> Energy source •  Both heat recovery and heat pump systems can use air or water as energy source (geothermal or water source) •  Modular design •  3-30 ton per system for air source •  6-48 ton per system for water source •  Air source units can be installed on the roof or inside ducted to the outside. •  Water source units are installed in mechanical rooms 12 Indoor units •  Wall mounted •  1-Way cassette •  2-Way cassette •  4-Way cassette •  Low static ducted •  High static ducted •  Floor standing •  Ceiling suspended •  Vertical air handler •  Medium or high temp water heater •  Things to consider when choosing an indoor unit •  Air distribution •  Noise •  Ceiling space 13 •  Budget Hydro Kit Uses the energy in the cooling season to heat the water Can be used for the radiant floor heating HR Unit Refrigerant Cooling/heating Air Source Hot water Hot water heating High temp heat Water Source Cold water cooling HR Unit 14 Hot water floor heating Heat/Cool Controls •  Controls are ‘’built in’’ the system = no need to add sensors •  Thermostat is connected with a quick connect to the indoor unit •  Daisy chain between all the indoor units and the outdoor unit •  Adding a central controller of your choice to the outdoor unit gives full access to the system •  Integration to the building management system –  BACnet –  LonWorks •  Touch Screen •  Individual billing •  Auxiliary heating module 15 Selection software •  Pipe sizing for the installer •  Capacity correction •  Piping length limitation •  Pdf report •  AutoCAD schematics for engineers •  Refrigerant amount calculation Service software •  Temperature sensors reading •  Refrigerant pressures •  Compressor speed •  Fan speed •  Auto Diagnostic •  Electronic expansion valves opening •  Other valves open/close status •  Voltage and amp draw Things to watch out for… •  Choosing the right system for the right application •  Heat Recovery •  Heat Pump •  Making sure the refrigerant amount is within the CSA-B52 code for occupant safety •  Qualified contractors must be selected for quoting and installation •  Unqualified contractors put huge margins of safety in their quotes which makes the project over budget •  Unqualified contractors can make mistakes in the installation that are difficult to diagnose •  Certified contractor to do the service •  30 minute job can turn into a week of troubleshooting for an unqualified technician •  Sequence of controls must be clearly understood by everyone, everything is possible, but needs to be designed properly in the first place •  Fresh air is a separate dedicated system •  Work with a well established VRF brand to get proper technical support, training, spare parts and inventory Benefits for the building owner •  Comfort at all time, load matching capacity (20-100%) •  Lowest operating cost •  AHRI-certified products •  Selection software, easy to modify the design as the project scope changes •  Long pipe length capability gives flexibility to the designer •  LEED points •  Integrated system •  Indoor units •  Outdoor units •  Controls •  ERV •  Lowest maintenance cost •  Clean air filters •  Clean outdoor coil •  No square footage needed for the HVAC system (Air source) •  •  •  •  Easy installation Easy troubleshooting with the service software Only 1 contractor to call if there is a problem with the system Best solution for retrofit projects Commercial application District Griffin •  Cooling and heating in commercial and office spaces (first 6 floors) •  •  •  340 tons 110 ducted units from 1 to 8 tons Air source heat recovery systems for offices and stores •  Air source heat pump systems for restaurants •  BacNet gateway Bombardier office building •  •  •  •  •  •  Retrofit project on existing building LEED project 220 tons More than 100 ducted units from 1 to 4 tons Air source Heat Recovery Sync systems Removed all existing rooftops and ductwork to install VRF •  •  Enhance comfort and energy saving were the main reasons BACnet gateway Apartment building Aquasole •  •  •  •  •  •  •  Luxury apartments with view on the StLawrence River 110 tons 75 ducted units from 1 to 4 tons 9 story building Air source heat recovery systems (SYNC) Electrical baseboards as back up heat source Touch screen central controller Geothermal 1160 chemin du Golf •  •  •  •  •  •  •  Rental apartments 90 tons 104 ducted units from 1 to 3 tons Water cooled heat pumps Water loop designed at 32F in heating Gas fired boiler as back up heat for the water loop Touch screen central controller Hospitality Forestel Hotel •  Addition of 46 rooms to existing hotel, phase 1 of 3 •  40 tons •  46 wall mounted units (1 ton) •  Air source heat pumps •  Electric baseboard as backup heat •  BACnet Gateway School Laval College •  •  •  •  •  •  Cooling and heating of class rooms, phase 1 85 tons 35x 4-way cassette units (0.5 to 3 ton) Air source heat recovery system Hot water baseboard as backup heat BACnet Gateway 26 Thank you