Flower packing house is blooming efficient
A Priva BMS is at the heart of a new purpose-built, energy-efficient facility for JZ Flowers, a leading producer of floral bouquets for UK retailers. Located on the outskirts of Hull, the 5600 m2 packing house contains a myriad of energy-saving innovations, all controlled by the latest Priva hardware and software technology.
Until the mid-1990s, most people bought their flowers from florists, garden centres or garage forecourts. With the rise of the supermarkets, Jelle Zwemstra sensed a change was coming and set up JZ Flowers in 1997 in Hull to design, produce and package floral bouquets for supplying direct to supermarkets.Over 150 million stems are supplied every year, representing around 8% of flower bouquets sold by UK supermarkets.
With success came the need for a bigger and better facility. With its Dutch origins, engineers at JZ Flowers were aware of the capability of Priva technology, which also has its roots in the Netherlands. In addition Cambridge HOK, an integrator with extensive horticultural and Priva experience, happened to be located a mere mile from the designated build site close to the M62.
‘From the outset, it was a prerequisite that every aspect of controlling the JZ Flowers facility should be about maximising efficient use of energy as well as creating a comfortable working environment for the staff and ideal conditions for the cut flowers and bouquets,’ says Duncan Grant, technical manager at Cambridge HOK.
A Priva BMS controls and monitors all aspects of the building, from the 11 kV electrical power supply to all aspects of the machinery plant and control of lighting in each office and the factory. The biggest energy user by far is the chiller plant — essential 24/7 equipment to cool the goods-in and goods-out areas, which are typically kept at 5˚C.
Heat from the chiller’s condenser heats water in a buffer tank, which is then used to heat offices, amenity areas and the production area (kept at 18˚C). Heat is only rejected when the buffer tank is satisfied or not required.
The Priva BMS decides the optimum temperature for the buffer tank and keeps it as high as it needs to be, and no more. The advantage is that the chiller condenser temperature is minimised, improving its COP. The BMS takes into account the outside temperature and the various heating demands of the offices and production area; this calculation is updated every second.
An air handling unit supplies tempered air to the office at 18 to 19°C. A thermal wheel in the AHU is controlled by the Priva system.
The buffer tank also acts as a source for underfloor heating in the office and amenity areas. Individual offices and the canteen have fan-coil units to top up the heat as required or to provide cooling using chilled water. The FCUs are controlled using Priva’s Comforte modules and Comset CX displays. The latter allows occupants to raise or lower the temperature within pre-defined limits and check room temperature and status.
Each office uses occupancy detection to turn lights off and revert heating/cooling to a stand-by setting when it is not occupied.
‘There are no conventional boilers or electric heaters anywhere on site,’ says Duncan Grant. ‘The Priva BMS is juggling the various valves and other plant to make maximum use of available heat and direct it accordingly.’ There is a heat pump to produce additional heat if required, or cooling in the Summer for the offices and amenity areas. So far, the heat pump has never been called on to provide heat.’
The project at JZ Flowers uses a Priva Compri HX8E intelligent BMS and around 15 modules. There are also two HX4 units serving about 35 Priva Comforte modules. Priva Comset CX display units are located in each office, and there is a supervising PC running Priva TC Vision for onsite and remote control, and Priva TC History, which retrieves selected logged data online and saves it to an open database. Extensive use of the graphics features of TC Vision enable operators to easily visualise the state of all plant and the environment in the facility. There is an e-mail messaging service for the JZ Flowers maintenance team, and Cambridge HOK.
The production area is lit by around 120 5ft fluorescent tubes. A light sensor in the roof space measures the amount of natural light and feeds this information to the BMS, which determines how many tubes need to be activated in order to meet the required illumination levels. A timer switch set up in the BMS will dim the production area to a safety-illumination level between shifts, although push-button over-ride switches are available for full illumination if required.
‘There are energy meters on all the electrical distribution boards that feed information to the BMS, which makes energy management very easy,’ says Duncan Grant. ‘We’re also monitoring the security, fire sprinkler, borehole irrigation and off-mains drainage systems — with alarms flagged up by Priva if necessary. In fact, JZ Flowers is already looking at other uses for the Priva BMS, such as monitoring the production line equipment to gather information for productivity.’
Cambridge HOK also undertook the electrical contract for the project, which aided project completion in just four months. The company worked with Hull-based Airkool Contracts regarding air conditioning and chiller technology. Airkool has a remote log-in facility to the BMS for monitoring purposes.
‘The previous facility of JZ Flowers was pretty old-school to be honest,’ says Mr Grant. ‘It relied on conventional technology such as thermostats and manual light switches — quite inefficient. Now, however, they effectively have no heating bill for the production area or offices because it all uses recycled waste heat.
JZ Flowers is already planning its next phase of growth, involving another facility next to the present one. Virtually a carbon copy in terms of size, Cambridge HOK and Airkool will link controls and pipes between the two to share services where possible.
So pleased is JZ Flowers with its existing packing house that the contract for the next one didn’t even go out to tender; Cambridge HOK and Priva have already started work.