CARRIER® VRF: WAHID ENGINEERING AND RELIABILITY

High-Efficiency Air-Conditioners

Carrier VRF outdoor unit. Heat pump and heat recovery. 2-pipes. Connect up to 64 indoor units to one system. The use of an asymmetric scroll compressor means higher efficiency, decreased compressor losses and a smooth, quiet, reliable operation.

Out Door Unit:

Model Type Capacity Range, Tons Key Documents

HEAT RECOVERY
38VMR
Carrier VRF 38VMR Outdoor Heat Recovery

3-phase Heat Recovery 6.0 – 28.0 Product Data

HEAT PUMP
38VMH
Carrier VRF 38VMH Outdoor Heat Pump

3-phase Heat Pump 6.0 – 36.0 Product Data

SINGLE-PHASE HEAT PUMP
38VMH-1P
Carrier VRF 38VMH Single-Phase Outdoor Heat Pump

Single-phase Heat Pump 3.0 –

 

 Indoor Unite

Controls & Accessories:

Model Description Key Documents

WIRELESS REMOTE CONTROLLER
40VM900001
Carrier VRF Wireless Remote Controller

Wireless remote controller

NON-PROGRAMMABLE WIRED REMOTE CONTROLLER
40VM900002
Carrier VRF 40VM900002 - Wired, Non-Programmable Remote Controller

Wired remote controller (non-programmable)

PROGRAMMABLE WIRED REMOTE CONTROLLER
40VM900003
Carrier VRF 40VM900003 - Wired, Programmable Remote Controller

Wired remote controller (programmable)

TOUCH SCREEN WIRED CONTROLLER
40VM900005
Touch Screen Wired Controller

Touch screen wired controller

TOUCH SCREEN CENTRAL CONTROLLER
40VM900006
Touch Screen Central Controller

Touch screen central controller

24V INTERFACE
40VM900008
24V Interface for Carrier VRF

24V interface

BACNET INTERFACE
40VM900052
BACnet Interface

BACnet interface

VRF Or VRV?

What’s The Difference Between VRV And VRF?

Many people who ask this question, mistakenly interpret it as 2 different HVAC technologies. Actually, those are two different terms for the same type of HVAC technology. Based on Inverter technology compressors, the first VRV HVAC systems were invented by Daikin during the early 1980’s. As a technology leader in the HVAC industry, Daikin had registered the VRV term (which stands for Variable Refrigerant Volume1) as an official trademark. All other companies use VRF (Variable Refrigerant Flow2) for their similar HVAC systems. Eventually, VRF is the more common term for these types of systems, and this is the term that will be used for the rest of the article.

Wish to integrate your VRF to Home Automation system? Check out our simple solutions.

So What Is VRF?

It can easily be related to as the “Rolls Royce” of Air Conditioning Systems. It’s a very sophisticated technological air conditioning system, based on several principles:

Refrigerant only – where the refrigerant is the only coolant material in the system (in contrary to the chilled water systems, where the refrigerant is used for cooling/heating the water that is circulated throughout the whole system).
Inverter compressors that allow lowering power consumption with partial cooling/heating loads.
Several air handlers (indoor units) on the same refrigerant loop/circuit.
The ability of modular expansion (especially applicable for large projects, that can grow in stages).

Typical VRF System Structure

A typical system consists of an outdoor unit (comprising one or multiple compressors), several indoor units (often and mistakenly called “fan coils”), refrigerant piping, running from the outdoor to all indoors, using Reflet Joints (copper distributors in pipes) and communication wiring.

VRV / VRF HVAC connectivity diagam

 

 

 

 

 

 

 

 

 

 

 

 

 

Communication wiring consists of a 2 wired cable, chained from the outdoor to all indoors, creating an internal closed loop network, that is an essential part of any VRF installation.

As for the Control, each indoor is controlled by its own wired control panel, while there are some possibilities for wireless remotes (IR) and centralized controllers, enabling controlling all indoors from one location.

How Does VRF HVAC Work?

The operation logic of the VRF is fully built-in inside the system and is proprietary for each VRF manufacturer. The system gets inputs from the user (e.g. desired comfort temperature) and from the surroundings (outside ambient temperature), and according to that data, it implements its logic in order to get to the desired comfort conditions, utilizing optimal power consumptions.

The ability to adjust itself to the outdoor conditions is one of the main factors that make these systems so efficient, compared to the traditional water-cooled systems, based on chillers and fan coils.

Now, let’s dive in, and see how it works in details. Let’s take as an example a typical VRF installation, with one outdoor unit and multiply indoors.

In the beginning, the system is in standstill condition (everything is turned off).

Once a user turns one of the indoors “ON” by its local remote, the outdoor “gets noted” regarding it, and starts working. At this point, it will examine the outdoor conditions (temperature), the operating indoor requirements (operation mode, setpoint temperature), and will operate the compressor at the exact level, required to comply with the indoor requirements.

When another indoor unit is turned on, the outdoor recalculates the requirements from all the indoors and will increase the compressor’s output, according to the required level of demand.

This process is constantly occurring with any change, performed in the HVAC system. As described, this system is fully automatic and regulates its power consumption based on the demand arriving from the indoor units and outside prevailing conditions. User can have influence on the desired indoor comfort conditions, modifying: Operation mode (on/off), Operation state (Cool/Heat/Fan/Dry/Auto), setpoint temperature, fan speed (high/medium/low/auto). Controlling those parameters is the only thing required for proper operation and the only thing that is required for proper integration with the VRF system.

VRF System Types

Cooling only systems (less popular) – those systems can only cool. Heating is not available. Fan and Dry modes are available for each indoor unit independently.

Heat Pump systems (most popular) – all the indoor units can either heat or cool (not at the same time). Fan and Dry modes are available for each indoor unit independently.

Heat Recovery systems (less popular) – those systems are the most sophisticated ones, where cooling and heating may be available by each indoor unit, independently, at the same time.