What's new with City Multi

Single Setpoint found in traditional HVAC systems often restricts comfort

Standard Automatic Mode offers only one setpoint to the user. This would often prove problematic as the comfort of the inhabitant would be influenced by not only the space temperature but also the temperature of the incoming air from the air conditioning system. One setpoint with warm or recirculated air would be comfortable; however, the same setpoint with cool circulated air would feel uncomfortable. Add to this the requirement for the changeover from heating to cooling needing a deadband to prevent cycling and you would end up with a sudden drop in temperature once the mode changes.

Dual Setpoint is the next generation in comfort and energy consumption control

Dual Setpoint offers a solution to this issue by allowing a different heating and cooling setpoint with the system changing mode in between the two setpoints. This control is also ideal for large open spaces where a number of occupants are present with different comfort requirements.

By introducing a deadband between the heating and cooling setpoints, energy savings are offered by preventing over-heating and/or cooling the space.

Dual Setpoint – now built-in to City Multi Systems for ease of use

Previously a high-level BMS or additional controls were required to achieve this level of comfort. However, now this functionality is inbuilt in Mitsubishi Electric City Multi VRF and HVRF Heat Recovery Systems.

The New Zealand Government, having adopted the Kigali Amendment to the Montreal Protocol, has cemented us in the drive to reduce our global warming potential. This is impacting the decision-making process when designing HVAC systems, from the global research and design or manufacturing, all the way down to the type of unit we install into our homes and businesses here in New Zealand.

The market has seen the wider adoption of R32 refrigerant on a domestic level, and the increasing immergence of low GWP refrigerants such as R513 or R1234ze in the chilled water market, but the question still remains around the VRF / VRV market as to how we tackle low GWP refrigerants.

Mitsubishi Electric have been at the forefront of the VRF market for many years with the world’s first 2 pipe heat recovery VRF system. In 2014, they pioneered the world’s first Hybrid VRF (HVRF) system, incorporating VRF Technology into a hydronic-based fan coil system, providing the market with a 2 pipe heat recovery hydronic solution.

Again in 2019, Mitsubishi Electric have led the way by incorporating a low GWP refrigerant with Hybrid VRF giving the lowest GWP VRF-based system available. With a GWP potential as low as 20% of a traditional R410A VRF system, and no risk of refrigerant leakage into occupied spaces, R32 HVRF provides a convenient, modular VRF solution with advantages otherwise found in a 4 pipe heat recovery hydronic system.

Hybrid VRF is a simple premise. Using a traditional VRF condenser as the base of the design, engineers set about developing a hybrid branch controller which uses the same heat recovery principles of a traditional DX system. What sets this system apart is that it incorporates four plate heat exchangers as the condensing and evaporating devices to allow heat recovery to water rather than air.

By using the heat exchangers to absorb and impart heat to the water circuitry, HVRF is able to cool, heat or simultaneously heat and cool the circulated water out to the field devices. The Hybrid Branch Controller (BC) incorporates two separate variable speed DC pumps and manifold systems to direct the heated or cooled water to the required fan coil units. Using only two pipes between the branch controller and each indoor, while still being able to deliver both heating and cooling.

Coupled to a proprietary control system which considers the heating and cooling demand, as well as the flow rate of the system, there is no need for a complicated bespoke control and valve system with Hybrid VRF as there is with a traditional hydronic heat recovery system. This makes Hybrid VRF a very easy-to-use package.

R32 Hybrid VRF is the new era of VRF in the market. Mitsubishi Electric have strived to design a system which not only meets the legislative requirements being imposed on the market today, but also meets the future requirements that our market will have to adhere to.

The demand for high energy efficiencies, low global warming potential and improved corporate social responsibility is increasing. As a result, regardless whether operating on a global, national or regional basis, all businesses are being forced to look at their own buildings and how their decisions on capital plant will impact them over the life span of the product. As such R410A systems are becoming less viable. The cost of refrigerant is only increasing, with R410A cost per kilogram climbing rapidly based on the high GWP and the ETS tax imposed.

As business owners, design engineers, installers and suppliers of HVAC systems in New Zealand, it is our duty to provide the developers and building owners a robust future-proof solution to best suit their building and occupants needs. It is imperative we observe occupant safety and ensure our decisions will not have a lasting impact on our environment for the future.

BDT and Mitsubishi Electric are dedicated to leading the market with innovative products and initiatives which ensure our social corporate responsibilities are upheld; protecting ourselves, our stakeholders and the public.

For more information on R32 Hybrid VRF Technology, click here.

Black Diamond Controls is a Building Management System that natively integrates our diverse product range alongside third party devices. Ventilation products, VRF, chilled water, Ecodan, energy monitoring and more can now be integrated into a single unified platform to provide monitoring and control. With this level of system integration the scope for energy performance optimisation can be increased.

From small hospitality applications through to large commercial and health care facilities, Mitsubishi Electric can tailor a custom Building Management System solution specific to your project requirements.

A Wide Product Range to Satisfy a Variety of Needs

Our BMS product range covers a wide area, from programmable controllers through to field devices such as sensors, control valves and energy meters. Mitsubishi Electric work with a range of established product suppliers to ensure we can offer suitable engineered solution for each individual project.

Built on the established and industry leading Tridium Niagara Framework^®, the DC-8000 JACE Controller operates the latest revision of the Niagara 4 Platform and is designed to integrate diverse building systems and devices into one seamless Building Management System.

Interface devices such as the MelcoBEMS Mini provide additional flexibility for incorporating single heat pump units into a BMS solution.

BMS and City Multi – An All-In-One System

Our BMS products complement and expand the capabilities of our current City Multi offering. The flexibility of fully programmable BACnet Controllers and access to a wide range of peripheral sensing and control devices allows increased system functionality.

Plant Optimisation for Maximum Operation Potential

Increased focus on operational cost and carbon reduction is driving energy optimisation opportunities in New Zealand. Through our applied product range we can supply, engineer and commission central chilled water plant optimisation solutions to suit any application.

Extracting the full potential from your mechanical plant under all operating conditions is essential to achieve the best system efficiency. With chilled water systems, how can you determine the best system efficiency point under varying operating conditions? Introducing the Central Plant Energy Control System (CPECS). This system continuously monitors operating parameters and reacts in real-time to achieve the lowest input energy operating point for the overall system.

CPECS is a brand agnostic solution, capable of being deployed on any system configuration and any manufacturer’s equipment. The optimisation platform runs on the Tridium Niagara Framework^® and incorporates measurement and verification with integrated monthly performance reporting.



With numerous optimisation projects delivered in New Zealand, we are achieving significant energy savings on air cooled and water cooled chilled water systems.

Key BMS Projects in New Zealand:

Ministry of Education – Rawhiti Shool, Christchurch

• An energy monitoring opportunity with BECA in Christchurch, where BMS capabilities were added to an existing City Multi System to provide off site real-time energy monitoring of the air conditioning and general electricity meters

Ruapehu Ski Club – The Lodge, Whakapapa Ski Field

• Includes a BMS system incorporated with Ecodan Hot Water Heating and HyperCore Heat Pump Technology
• Provides remote access and control capabilities for RSC members
• Features system scheduling and performance monitoring
• Enables energy monitoring and peak demand management

Te Omanga Hospice – Lower Hutt

• Offers a comprehensive BMS suite incorporating the complete HVAC system
• Features a customised user interface for system monitoring, scheduling and set point control

For more on Building Management Systems, please contact:

Jeremy Peck
021 194 8759
jeremyp@bdt.co.nz
BMS Sales Engineer

Ideal for Medical Practice Applications

Of all of the HVRF Systems sold in New Zealand to date, 33% have been installed at medical centres. Doctor-patient privacy is one of the key requirements for medical centres where consulting rooms are often fully sealed.

Refrigerant Concentration Limitations

These small footprint medical consultation rooms dictate the limitations on the refrigerant concentration allowed due to safety regulations, as laid out in ASNZS5149. In turn, additional refrigerant leak detectors are required, creating increased expenditure not just in capital costs but also ongoing maintenance of leak detection systems.

HVRF Mitigates These Factors as Only Water is Passed Through the Indoor Units

In the new amendments to the legislation, not only has the critical concentration limit been reduced, but under circumstances where refrigerant leak detectors are required, this is no longer the only measure that is acceptable according to ASNZS5149. Now at least two more safety measures should be implemented such as ventilation (natural or mechanical), safety shut-off valves, or a safety alarm.

What is Hybrid VRF?

Hybrid VRF is next generation technology from Mitsubishi Electric, the world leader in VRF Solutions. This unique 2-Pipe Heat Recovery VRF System replaces refrigerant with water between the Hybrid Branch Circuit Controller and the indoor units. This revolutionary design removes the need for expensive and on-going leak detection servicing and is specifically designed for occupied spaces where quiet, energy efficient, simultaneous heating and cooling is valued. Hybrid VRF provides a truly integrated solution for hotels, offices, hospitals and schools where occupant comfort is paramount.

The ETS and the Continually Rising Cost of Refrigerant

HVRF is not just about critical refrigeration limits. The cost of refrigerant, in particular R410A, is rising and has done so dramatically in the last 2 years with the introduction of the Synthetic Greenhouse Gas Levy which falls under the umbrella of the Emissions Trading Scheme (ETS). The New Zealand ETS puts a price on greenhouse gas emissions to provide an incentive to reduce emissions and in this case use alternative refrigerant gases that have less Global Warming Potential. The ETS has increased significantly with a rate increase (due January 1st 2019) to $41.55/kg of R410A contained in air conditioning units, and considerably more when purchasing additional refrigerant to charge a system. Prices have surged to as much as $100/kg in the New Zealand market.

The Following Projects All Benefited from Cost Saving on Refrigerant:

• Rototuna Junior High School
  This project benefited from comfortable off-coil temperatures in the classroom and low noise, minimising classroom disturbance.
• Rotorua Children’s Health Hub and Library
  The use of water instead of refrigerant through the indoor units provided quietness and comfort within the library.
• Grafton Hall – The University of Auckland
  There was no need for leak detectors as there was no refrigerant in occupied spaces, saving on additional on-going maintenance costs.
• Burnett Holdings
  With no refrigerant in occupied spaces, HVRF proved to be the perfect solution for individual small offices.
• Boulcott Apartments
  The refrigerant restrictions in individual apartments also meant HVRF provided much quieter heating and cooling with low refrigerant cost for building owners.

Other Benefits of HVRF

• HVRF is also a heat recovery system and provides high efficiencies.
• HVRF is flexible and simple to design and install, incorporating the same control network and architecture as CITYmulti VRF.
• The decentralised system means phased installation is possible with the same high levels of seasonal efficiency expected with VRF.
• With water at the indoor units, HVRF provides comfortable and stable air temperature control; enhancing occupant comfort and making it an attractive option for many commercial applications.

To learn more about HVRF or read additional case studies click here.

Evolving Data to Real-Time Visualisation

Moving from the older data table format, this newly updated version now features a new diagram format to help Service Technicians to more quickly quantify system performance and quickly identify any problem at a glance.

The new City Multi VRF Service Tool condenses the entire system into a diagram, showing key components of each system for up-to-the-minute, simple monitoring in one place.

The diagram showing information related to a specific component is displayed next to it for quick referencing, so Service Technicians can easily see the value of any sensor, position of any valve or speed of any motor in its place on the refrigeration circuit in real-time, to accurately monitor the system and fix any issues that arise.

In the below example outdoor unit, we can easily see:

• Compressor outlet temp = 96.6°C
• Compressor crankcase temp = 41.8°C
• Compressor speed = 72Hz
• OU fan speed = 530rpm
• OU coil refrigerant temp = 23°C in / 5 °C out

• Fan speed = High
• Mode called for = Heating
• Refrigerant = 69.9°C in / 35.7°C out
• Return air temp = 23°C
• Valve position = 495 pulses open

Graphs Parameters Easily for Additional Reporting

The updated software now enables Service Technicians to graph any parameter being recorded to see a trend over time for accurate reporting and control. And, with the ability to graph multiple parameters against each other on the same time scale, comparative reporting is even easier.

For example, the graph below shows:

• Compressor outlet temperature (TH4)
• BC Box sub cooling outlet temperature (T5)

The Control is in Your Hands

With the newly updated Service Tool from Mitsubishi Electric, the servicing and maintenance of City Multi VRF Systems can be done at a glance with an easy-to-use, customisable online tool that not only saves time with reporting key data but will ideally save down-time onsite also.

Want to know more? Click here to learn more and download the Service Tool from the secure login section.*

* Note that the firmware of the ODU may require upgrading to enable the new software to work correctly. BDT can offer this firmware upgrade on a case by case basis to sites which require it. Please contact your local sales or service representative for more information.

Introducing Mitsubishi Electric QAHV CO₂ Hot Water Heat Pumps

More than ever, business owners are now looking to more environmentally friendly solutions to help provide core services to their customers when they need it most. So, Mitsubishi Electric have engineered the perfect solution; the QAHV CO₂ Hot Water Heat Pump. The Mitsubishi Electric QAHV trans-critical hot water generator incorporates natural CO₂ refrigerant rather than R410A which heating systems traditionally used. Now, hospitals, gyms, hotels and many other services can provide secure and reliable HVAC hot water supply with reduced cost and CO₂ emissions.

With a zero Ozone Depletion Potential (ODP) and a low Global Warming Potential (GWP) of 1%, in compliance with the Kigali Climate Change Agreement, QAHV also boasts a highly efficient COP rating of 3.88* at standard conditions.

Ideal replacement for inefficient traditional boiler systems

Mitsubishi Electric QAHV is set to replace ageing, inefficient boiler systems and are increasingly being specified in new industrial and commercial projects where high volume electric hot water generation costs could affect a business’s pockets. Mitsubishi Electric QAHV utilises advanced inverter compressor technology combined with an inverter controlled primary pump to optimise the heat exchanger delta T and overall system COP in all load conditions.

Unique Heat Exchange Technology

With advanced “twisted spiral gas cooler” technology unique to Mitsubishi Electric, maximum heat exchange is ensured while maintaining strength and structural integrity under the CO₂ high gas cooler operating pressures. The continuous spiral grooves of the water pipe design with the gas pipe wound around optimises water turbulence while maintaining high efficiency heat exchange, reducing pressure loss in the heat exchanger.

Environmentally friendly with superior energy efficiency

QAHV is an environmentally friendly solution to low ambient high temperature water supply. With a rated 40kW output capability down to sub-zero conditions** and operation down to -25°C while providing up to 90°C supply hot water, QAHV combines superior energy efficiency with optimum performance. This level of performance in the past has been the domain of much cheaper capital cost gas, oil or electric boiler systems. But, with high ongoing energy costs throughout its lifetime, increased environmental concerns and high maintenance costs around traditional heat sources, Mitsubishi Electric’s QAHV provides a long-term cost-effective maintenance solution.

Ideal for high temperature, large volume water applications

For engineered design solutions for large potable high temperature hot water storage (e.g. industrial wash downs, leisure facilities, hotels) the QAHV will ensure high temperatures of up to 90°C which opens up many industrial and commercial opportunities.

Of course, this exciting new product will be accompanied with the exceptional level of technical support, commissioning, and maintenance expertise that give our customers the confidence and security to invest in Mitsubishi Electric products. QAHV from Mitsubishi Electric: The high volume, high temperature commercial grade hot water supply solution for your next project.

Ideal applications:

• Gyms
• Hotels
• Schools
• Shopping Malls
• Universities
• Factories

The Next Generation in Water Sourced VRF

Introducing Mitsubishi Electric PQRY Water Sourced VRF Systems. These unique systems use water to offer a solution to a range of common challenges such as limited plant space, long refrigerant pipe runs and compliance to standards while retaining the advantages of VRF and the benefits from very high efficiencies.

City Multi PQRY units connect to a central (condenser) water loop and extract energy from this. That energy is then used for simultaneous heating & cooling in a similar fashion to a common air sourced VRF system.

Mitsubishi Electric Water Sourced units are specifically designed for commercial applications such as hotels, commercial buildings, office buildings, and so many more applications, either as new builds or retrofits. With a small footprint and the ability to reject energy to the building water loop instead of the air, water sourced VRF allows you to bring the outdoor units inside and reduce plant size when:

• The outdoor plant space is limited
• The buildings external outdoor aesthetics are critical
• Pipe runs or pipe lifts are large

This flexibility means reduced costs, more usable space, no defrost cycle and the ability to bring the unit closer to the air conditioned zone, therefore reducing the additional refrigerant volume required (a dual benefit of lower refrigerant cost and improved compliance with NZS5149).

A Water Sourced System with the Benefits of VRF

Water sourced outdoor units are available in heat pump (heating or cooling) and simultaneous heating and cooling configurations with no change to the internal system design from our standard VRF, thus retaining VRF’s modular design style and removing the need for bespoke controls or valves as seen on chilled water systems. This makes Mitsubishi Electric PQRY an easy solution for end of life replacement jobs or when capital costs need to be spread out as the separately operating VRF systems allow for staged installs with the added benefit of much improved redundancy.

Utilising the wide operating water temperature range of 10-45°C, you can also reduce the size of the external heat rejection plant, take advantage of waste heat from server rooms, and connect to energy sources such as nearby rivers, lakes or a geothermal loop in order to reduce upfront costs and long-term energy usage.

Increased Efficiencies with Heat Recovery

Mitsubishi Electric PQRY features the same patented heat recovery technology at the indoor units as also found in Mitsubishi Electric 2-Pipe Air Sourced VRF units, which provides real world efficiency increases and running cost savings. With multiple water cooled systems, an additional heat recovery stage is obtained at the outdoor units through the buildings water loop. Often, PQRY full load COP’s without heat recovery will exceed 5.0 and can improve significantly further with double heat recovery.

Other Key Features of Mitsubishi Electric Water Sourced Systems

• No requirement for ventilation around the unit, therefore offering installation cost savings
• More efficiency by offering dual heat recovery at the outdoor and indoor units
• Smaller footprints which offer improved plant space flexibility
• Uses a modular, non-bespoke design making implementation easy
• Is a 2-pipe system throughout the entire building with simultaneous heating and cooling which saves on installation costs compared to 4-pipe chiller or 3-pipe VRF systems
• Includes improved redundancy as each system operates independently and allows for staged installs; spreading capital costs and reducing loads on existing chillers for replacement jobs.

If your client is looking for a total air conditioning system that is super energy efficient, has a small footprint, is sustainable and will reduce capital expenditure, Mitsubishi Electric PQRY Water Sourced VRF is the perfect solution to recommend for your next commercial project.

For more information about Mitsubishi Electric PQRY Water Sourced VRF, please contact your local Sales Representative.

BDT’s latest solution to the commercial building market is City Multi Hybrid VRF, the next generation of heat recovery systems for commercial buildings.

HVRF is a 2-pipe heat recovery system which replaces refrigerant with water between the BC Controller and the Indoot units, so there is no refrigerant in occupied spaces while providing higher efficiencies. You can also install and design it as a VRF whilst enjoying the features of a chiller system.

The SGG levy in New Zealand has put extra cost on purchasing synthetic greenhouse gases and this cost is set to increase, pushing up the price of refrigerants such as R410A. HVRF reduces this burden as it has less refrigerant in the total system. HVRF is ideal for applications where the limitation of refrigerant in occupied spaces is required, in particular where occupant safety is paramount. With no refrigerant in the occupied room space, this removes the need for expensive leak detection systems with ongoing maintenance costs.

HVRF is simple and flexible to design and install using the same control and network as VRF systems. Furthermore, the decentralised system means phased installation is possible with the same high levels of seasonal efficiency expected with VRF. With water at the indoor units, HVRF provides comfortable and stable air temperature control enhancing occupant comfort. Modular, small footprint and low weight outdoors makes for manageable phased installation. HVRF is a fully packaged solution; valves, pumps and heat exchangers are all contained within the HBC Controller with minor third party items required, making commissioning simpler.

• Schools
• Medical Centres
• Libraries
• Hotel
• Office
• Hospitals

The highly efficient E-Series Modular Chiller Range, with an ESEER of 5.66, is designed to answer the need for controllable, energy efficient cooling and heating with reduced plant size and a host of advanced features and benefits taken straight from Mitsubishi Electric’s experience in the air conditioning industry.

The E-Series Modular Chiller is available in either a cooling only version or as a highly efficient heat pump model that uses two advanced DC inverter-driven scroll compressors in each 90kW module. Soft Start Technology means that the starting current is only 8 Amps per module, where a conventional style chiller would pull up to 180 Amps on start-up. This reduces mechanical and electrical stress improving equipment longevity.

Whether one module or six, the deliverable capacity range is between 8% to 100%. The E-Series Modular Chiller delivers market-leading levels of efficiency with the ability for units to operate on their own or in conjunction with others.

The unique shape and modular design of the E-Series Modular Chiller means that the system can be constructed with up to six individual units connected together, to provide a total capacity between 90kW and 540kW. This also provides outstanding redundancy due to multiple refrigerant circuits.

The use of U-shaped high performance air heat exchangers offers a greater surface area, for higher heat exchange efficiency, this and the units are narrower than conventional systems. Each 90kW module can be positioned next to each other in a row, with up to six units using the same inbuilt, internal header. For larger systems, it is also possible to have double rows of the units with a gap of only 900mm service space plus it can be designed as a double-row double stack, offering space saving where plant area maybe limited.

The E-Series Modular Chiller achieves low noise levels which is increasingly important in inner city locations. These low noise levels are achieved through both the unique construction and design of each unit, as well as the advanced component technology within each chiller.

The E-Series Modular Chiller is easily integrated with new and existing BMS systems, either hardwired or via MelcoBEMS Mini Interface it can be remotely controlled and monitored, ideal for facilities management.

As of September 2018, the Mitsubishi E-Series Range has been extended to now include 150kW & 180kW modules.

With similar technical features & providing excellent efficiencies, the P1500 & P1800 Models are a more traditional shape with vertical discharge condenser fans. Available in both cooling only & heat pump models, up to six of these modular chillers can be connected in one system.

• Energy recovery through the permeable core not only recovers sensible heat but also latent heat from humidity in the air, further reducing load on HVAC plant and saving on energy consumption.

• Lossnay’s total energy recovery rate is typically in the order of 70% ~ 75%. This is higher than common efficiencies seen for a solid core ventilator which transfers sensible heat only.
• At 0°C outdoor air temperature, and a space temperature of 20°C, supply air from a Lossnay unit can be around 16°C – which is warm enough to supply directly to a fan coil unit without any expensive additional top up heating.

• Transferring latent heat (humidity) also helps maintain an acceptable relative humidity within the occupied space. With Lossnay, air introduced into the space is closer to the space humidity than other uncontrolled ventilators. Without Lossnay, air is typically preheated and humidified in Winter and precooled and dehumidified in Summer.

• All LGH Lossnay units come standard with a Bypass Damper allowing for free cooling and night purge. Internal settings also prevent the unit from operating on bypass when supply air will be below an acceptable temperature.
• Lossnay is able to communicate with Mitsubishi Electric Air Conditioning units allowing for the Bypass Damper to provide free cooling based on the connected indoor units mode of operation. This removes the need for any expensive additional controls.

• Air processing locally removes the need for large roof mounted air handling units. Riser space can also be minimised by using smaller intakes closer to the space.

• Lossnay removes issues associated with traditional methods of supplying untreated fresh air in summer and utilising electric heater banks for Winter. These old methods are no longer seen as acceptable as they commonly cause high running costs in Winter and problems such as poor cooling performance and condensate dripping from supply duct / grilles in Summer.

• LGH Lossnay’s are quiet in operation with even the largest unit only producing 41dBA at 1.5m below the unit on high fan speed.

• Outside and Exhaust Air Filters are provided as standard for core protection. An optional high efficiency filter can be fitted into the unit to filter the supply air to rating F7 (EU7).

• Service accessibility is required to one side of the unit only. The electrical panel, core and filters can all be accessed through the one access panel.

• PZ-61DR-E Wall Controller allows for the following additional functionality:
  - Display of outside air, exhaust air and calculated supply air temperature.
  - Function settings allow for fan speeds to be increased slightly to achieve airflow if slightly short.

• Inbuilt logic allows CO₂ control through input via a third party 0-10V CO₂ Sensor.
• Positive or negative pressure can be achieved by offsetting supply and exhaust fan speeds.
• Test data for gas transmission shows this is very low - less than 3% for all gases tested.
• Test data for bacterial transmission shows no bacteria is transferred between the exhaust and supply air streams.