ASHRAE Presentation: VRF Overview Mitsubishi Electric Presenter: Phone number ©2011 Mitsubishi Electric& Electronics USA, Inc.

General overview of VRF Technology Review of Design Considerations Benefits of VRF Agenda

Variable Refrigerant Flow (VRF)

Heat Pump versus Heat Pump with Heat Recovery

Heat Pump

Outdoor Unit Indoor Units Controls System Heat Pump

Outdoor Unit Indoor Units Controls System

Heat Pump Applications RestaurantsLobbies Others? Churches

Heat Pump with Heat Recovery Simultaneous Cooling & Heating

Outdoor Unit Branch Circuit Controller Indoor Units Controls System Heat Pump with Heat Recovery Simultaneous Cooling & Heating

Heat Pump with Heat Recovery Outdoor Unit Branch Circuit Controller Indoor Units Controls System Simultaneous Cooling & Heating

Heat Pump with Heat Recovery Applications Schools Assisted Living Facility Offices Others? Simultaneous Cooling & Heating

What is the purpose of each component?

Controls compressor speed Controls condenser fan speed Controls pressure of refrigerant to maximize capacity and efficiency Outdoor Unit

Separates refrigerant into gas and liquid Ensures units in heating receive superheated gas Ensures units in cooling receive sub-cooled liquid Branch Circuit (BC) Controller

Sense the space temperature Contain a Linear Expansion Valve (LEV) that automatically modulates Allow the precise amount of refrigerant through the heat exchanger Filter and distributes air Indoor Units

Integrated sequence of operation Takes input from the user and provides feedback to the system Controls System

What system type requires a Branch Circuit Controller? Which system type cannot provide cooling and heating simultaneously to connected units? Is there any difference between the controls offered for Heat Pump Systems versus those offered for Heat Pump with Heat Recovery? Recall

VRF Design Considerations Equipment LayoutDiversityVentilationHeatingEfficiency

Equipment Layout DiversityVentilationHeatingEfficiency

20 Ton System Ceiling Space Rectangular Ductwork(DX System) 40” x 20” Round Ductwork (DX System) 30” Round -Piping (4Pipe System) 3” CHWS&R, 3” HWS&R 3 / 1 / 8 Piping (VRF) 1 8 ” Gas 1” Liquid Equipment Layout DiversityVentilationHeatingEfficiency

Rooftop Equipment Weight 80 Ton System Equipment Layout DiversityVentilationHeatingEfficiency

Vertical Stack WSHPs Equipment Layout DiversityVentilationHeatingEfficiency

Water-source VRF Equipment Layout DiversityVentilationHeatingEfficiency

There are piping considerations for: ▫ Total System Piping Length ▫ Intermediate Lengths ▫ Elevation Differentials Piping Lengths Equipment Layout DiversityVentilationHeatingEfficiency

Outdoor Units ▫ Consider location of unit ▫ Consider area drains and floor stands BC Controller ▫ Drain pipe connection Indoor Units ▫ Drain pipe connections ▫ Some styles include standard condensate lift mechanism ▫ All styles include contact for condensate alarm/safety switch Condensation Equipment Layout DiversityVentilationHeatingEfficiency

Diversity Equipment LayoutDiversityVentilationHeatingEfficiency

E Solar Diversity W 5 Tons Morning 5 Tons Morning 3 Tons Morning What is the sum of the zone peak loads? 5 Tons Afternoon 3 Tons Afternoon 3 Tons Afternoon N S What is the block load? What is the block load? Equipment Layout DiversityVentilationHeatingEfficiency

OPEN OFFICE 101 WORK ROOM 103 CONFERENCE 105 COFFEE 105A Occupant Diversity Equipment Layout DiversityVentilationHeatingEfficiency

OPEN OFFICE 101 WORK ROOM 103 CONFERENCE 105 COFFEE 105A What is the sum of the peaks? What is the sum of the peaks? Occupant Diversity What is the block load? What is the block load? Equipment Layout DiversityVentilationHeatingEfficiency

COOLING HEATING What equipment is running? Waste Heat Building Diversity Equipment Layout DiversityVentilationHeatingEfficiency

Connected Capacity: ▫ Connect up to 150% of the outdoor unit capacity. Actual Capacity: ▫ The actual system capacity is the capacity of the associated outdoor unit. A system cannot provide more than 100% of the outdoor unit’s capacity. Designing with Diversity Contact your local representative when designing at greater than 110% connected capacity. Equipment Layout DiversityVentilationHeatingEfficiency

Example: Indoor units totaling 14 tons can be connected to a 12 ton outdoor unit ▫ Connected Capacity = 14 Tons, 117% ▫ Actual Capacity = 12 Tons, 100% The maximum amount of cooling that can ever be provided at a single instant is 12 tons Designing with Diversity Contact your local representative when designing at greater than 110% connected capacity. Equipment Layout DiversityVentilationHeatingEfficiency

Ventilation Equipment LayoutDiversityVentilationHeatingEfficiency

Duct required Outside Air (OA) directly to space or indoor unit ▫ Always calculate entering coil temperatures Use Dedicated Outside Air System (DOAS), Energy Recovery Ventilator (ERV), or both to temper the air Adhere to local codes in designing ventilation Ventilation Equipment Layout DiversityVentilationHeatingEfficiency

Heating Equipment LayoutDiversityVentilationHeatingEfficiency

Utilize manufacturer’s design software Minimize connected capacity for colder climates Outside Air Consider Building Warm-up Special Considerations for Heating Equipment Layout DiversityVentilationHeatingEfficiency

Equipment LayoutDiversityVentilationHeatingEfficiency

INVERTER-driven compressor matches compressor speed exactly to load Simultaneous cooling and heating allows heat recovery between zones All efficiency values now available via AHRI Directory ▫ Efficiency Equipment Layout DiversityVentilationHeatingEfficiency

System Type Roof Top Units Air-Cooled Chiller Air-source VRF Water-source VRF IEER EER IPLV SCHE N/A 20 Ton System Equipment Layout DiversityVentilationHeatingEfficiency

Two-pipe System INVERTER Technology Multiple Indoor Units Variable Capacity System Zoning System Complete Control Offering What are the benefits of VRF?