JD COOLING | Top Tips

If you are currently mobilising a home working strategy, please don’t overlook your office air conditioning.

 

Save energy and turn the system off before you leave if you can, or reduce the  operation on the time clock.

Danfoss ‘Help’ Animations

JD COOLING | Top Tips

Ever wondered how a thermostatic expansion works? Danfoss Cooling have produced a great series of animations that demonstrate how Danfoss products such as solenoid valves, stepper motor valves, and KP switches work. These are really useful visual guides that help learning and understanding.

 

Thank you to Danfoss and World Refrigeration Day for sharing these animations. Keep up-to-date with more animations from Danfoss here.

Top Tips: Maintaining Your Air Conditioning System

JD COOLING | Top Tips
  • Ensure your plant is regularly serviced to keep it running effectively and efficiently
  • Raise the set point in the summer by 1 or 2 degrees to save energy and running costs. 22oC is still comfortable when it is hot outside
  • Lower the set point in winter for the same reason. 19oC is still comfortable when it is freezing outside
  • Run your server room at a higher set temperature. 26oC is pretty standard practice now and will have a huge impact on running costs and energy use
  • Do not be afraid to turn the office air conditioning off and open a window, however do not open a window and have the AC on at the same time
  • Do not adjust the set point more than a couple of degrees at a time – allow the system time to stabilise
  • Use a low fan speed and adjust the vanes to direct the air – auto is not always the best function
  • Keep the return air filter clean to prevent bad smells
  • Set-up your system time clock effectively to prepare for the day ahead, but also to save energy when not occupied
  • Never under estimate the benefits of fresh air – try to utilise your air conditioning for when it is really needed

Top Tips: Maintaining Your Clean Room Air Conditioning System

JD COOLING | Top Tips
  • A clean room HVAC system requires more attention than standard air conditioning systems. Ensure your plant has a suitable PPM to meet the critical requirements of your facility
  • Ensure any return air grilles are kept clear and clean
  • Ensure your clean room garments cover all of your clothing and are suitably sized. Personnel and their activities are one of the major sources of room particulates
  • Regular checks to all doors and product access points should be a priority – these are by far the biggest cause of room pressure loss in a facility.
  • Set out a short to medium term plan to better seal your facility. By reducing leaks, the volume of conditioned ambient air can be decreased, resulting in a huge cost and energy saving
  • Consider preparing for your re-validation by having a dedicated clean room team test – service the room in the months leading up to it and reduce the risk of downtime
  • Older systems may have been designed to lower ambient conditions. A water spray bar (adiabatic) on the external coil may give you that additional capacity when the mercury rises
  • Consult your clean room specialist before you make a change in the room. Most clean rooms are bespoke to the process in which they were designed for. Changes may have a big impact to its operation
  • Consider the classification of your room and if the air changes, rates and pressure differentials could be lowered. Reducing fan power and conditioning the ambient air will cut your energy use
  • Changes to ISO standards are always on the horizon, stay in touch with us on Linkedin for the latest updates (they may save you thousands).

Top Tips: Maintaining Your Electrical Installation

JD COOLING | Top Tips

An electrical installation is the lifeblood of the business, and directors managers are often faced with difficult decisions to ensure uninterrupted power when dealing with budget cuts. Cost cutting often leads to reduced maintenance, and team strength. This will lead to taking an on-demand approach to repairs. The principal reason for electrical system failure is lack of maintenance. All electrical equipment requires regular maintenance to optimise operations, avoid breakdowns, and ensure safety.

Regular inspection, testing and verification of an electrical system is essential in confirming both safety and operation. The Health and Safety at Work Act 1974, the management of Health and Safety at work regulations 1999, and the Electricity at Work Act all place a duty of care on employers to ensure the safety of their employees, and the need for good maintenance to be carried out to achieve this.

 

Top tips for maintaining your electrical installation

  • Records should be kept of all inspections and remedial actions carried out as a result of these tests. Particular attention should be paid to emergency and life safety systems (fire detection and alarms for example) which should be the subject of more onerous testing requirements.
  • Only allow suitably trained, and competent persons to carry out work on electrical systems.
  • Wiring diagram/as installed drawings of the whole installation should be made, and kept safe ready for use when required.
  • All circuits must be identified, and as a general rule of thumb in the workface, socket outlets, light switches, and other forms of electrical switching/isolation devices should be marked with the circuit reference. Distribution Board charts should be positioned in each board showing the services provided by it.
  • Users can be instrumental in ensuring that the integrity of an electrical installation remains, by ensuring that anything connected to it is in a serviceable condition, and not likely to cause any damage to it when added.
  • Visual inspection of cables/flexes in everyday use can prevent electrical faults/fires particularly in areas in which they are subject to constant repositioning/movement and a lot of personnel traffic (e.g. busy offices, warehouses, call centres etc.).
  • Broken plugs/sockets, cut/ frayed cables, all should be replaced/repaired immediately, and should not be used until that work is completed.
  • Frequent blowing of fuses or the tripping of protective devices may indicate that there is a continual fault or problem with your electrical systems. Further investigation should be carried out by suitably trained and qualified personnel.
  • Don’t use ordinary electrical cables and appliances outdoors if they are not approved for outdoor use. Indoor electrical systems and equipment is not designed to withstand the elements and it could be potentially dangerous to use them outside.
  • Maintenance regimes in factories, workshops, storage buildings, and anywhere that electrical installations/systems are installed, will be affected by poor electrical servicing/testing, and awareness. It may not be a problem today, but it might well be tomorrow.
JD Cooling Electrical Installation

Top Tips: How To Deal With Compressor Failure

JD COOLING | Top Tips

The following items are possible and common causes for compressor failures, which need to be identified and rectified before and during the commissioning of new / rebuild compressors.

 

1. Dirty Condensers:

Check that airways are clear, which may require jet washing or blown through with nitrogen, as any reduction in air movement will increase head pressure, which in turn causes premature stress to the plant and poor performance.

 

2. Dirty Evaporators:

Check airways are fully clear, which may require jet washing, as blocked evaporators will potentially lead to liquid return to the compressor / pack, which in turn, will cause mechanical damage or worst case, a full failure to the compressor.

 

3. Iced-Up Evaporators:

Check airways are fully clear of ice. Check defrost heaters and controls to ensure the evaporator heaters are functioning as design. A blocked evaporator will potentially lead to liquid returning to the compressor / pack, which could lead to mechanical damage or worst case, a full failure to the compressor.

 

4. Incorrect Pressure Control:

Erratic pressure control with the incorrect settings for the condenser fans will lead to the plant being inefficient, causing high discharge pressures, which in turn causes premature stress to the compressor. Incorrect condenser fan control can also cause over condensing, which causes lower pressure across the system and the potential to produce liquid migration to the compressor plant.

 

5. Incorrect Refrigerant Charge:

A prolonged lack of refrigerant within the system will minimise sufficient suction gas to return to the compressor to cool the compressor windings, therefore decreasing the life expectancy of the windings.

 

6. Incorrect Expansion Valve Control Settings:

The correct setting and actual checking of the superheat for any system is vital to ensure adequate refrigerant and temperature is entering / leaving the evaporator, which in turn will ensure the compressor has sufficient suction gas to cool the windings and minimise liquid return to the compressor sump.

 

7. Worn Contactors:

Worn contact phases on contactors could lead to single phasing of the electrical supplies to the compressor, or worst case a complete electrical failure – resulting in a possible motor failure.

 

8. Loose Wiring / Terminals:

Loose wiring or terminals could lead to single phasing of the electrical supplies to the compressor, or worst case a complete electrical failure – resulting in a possible motor failure.

 

9. Loose Compressor Support Fixings:

Loose fixings or support components of the compressor feet could lead to a mechanical failure if regular checks aren’t carried out to ensure the compressor is sufficiently in position.

 

10. Compressor Sump or Strap on Heaters:

During the winter months or long periods when the compressor plants are idle, it’s very important to make sure the sump heater(s) are working to maintain the oil temperature and to prevent any liquid migrating to the compressor sump. A compressor being off for a period of time or one that has been replaced with new, the heater needs to be switched to allow the oil to be heated to the manufactures guide to prevent mechanical failure during the start-up.

 

Please note:

Consider investing in a bespoke JD Cooling preventative maintenance package, which will reduce the number of untimely breakdowns, caused by compressor electrical / mechanical issues.

Top Tips: How To Get The Best From Your Hydrocooler

JD COOLING | Top Tips
  • Always ensure that your tank of water is pre-cooled to the set-point temperature prior to production starting; this should be around +0.75 to +1ºC max (a simple timer can be fitted to allow this to happen automatically)
  • Prior to your busy season, make sure that your plant is fully serviced so that it can achieve its maximum potential. Once underway, check weekly the area around your external plant and ensure that the condenser is completely clean and not blocked by seedlings, leaves, paper or packaging. Remove all such blockages carefully so as not to bend the delicate fins on your condenser coils.
  • At the start of your busy season, check the speed setting on your conveyor using a coloured tennis or golf ball. Place this on the conveyor just at the entry point of product as it goes under the water drench. Time the period it takes for the ball to exit this drench at the output end of the machine. Depending on product type and size, this time should be 15 – 25 minutes, and never less than 15 minutes for summer crop temperatures. Adjust your belt speed using either the inverter or gearbox control. Most machines would be designed for a crop on belt depth of around 600mm (2 ft) at peak design throughputs. Do not adjust the belt speed for lower throughputs, only adjust according to seasonal trends. For example, for winter crops you could speed up the belt to around 10-minute dwell time for higher tonnage.
  • At the start of your season, check the water flow over your coils. This should be set so that the trays have a full level of water (this will vary across the trays, but it should be possible to achieve flow through all of the holes in the trays) and the pumps are delivering their maximum flow without overflowing the intermediate coil distribution trays.
  • Check your water condition daily. Chemical treatments need to be carefully controlled to ensure that the cooling coils are not corroded. These may control bacterial counts but the actual water cleanliness is important to water distribution so consider changing your water every two or three days. This may vary according to harvest conditions and water filtration efficiency. The old water from the Hydrocooler can be used to fill pre-washers which will save water and also see that they are filled with cooler water than ambient systems.
  • Check your water distribution hourly. The top tray system that feeds the coils can become blocked and this will destroy the design water flow pattern and thereby reduce cooling efficiency from the coils. A squeegee can be used to force through particulates so that they go back into the system and get filtered out, leaving the trays flowing freely at the upper level.
  • Cooling coils will become dirty from the recirculating water. A film of slime can build on the coil pipework and this will drastically reduce cooling efficiency from the coils. Coils should be thoroughly cleaned weekly by removing the intermediate water trays and any side covers to allow a pressure lance to be used to remove this slime build-up from the side and top of the coils.
  • Use borehole water to fill and top-up your machine wherever possible. Borehole water tends to be lower in temperature than mains or stored water and will reduce the cooling demand on your plant.
  • Consider adiabatic cooling for your condenser. During peak conditions it may be possible to increase your cooling capacity by up to 10% by lowering the outside air temperature on to your condenser coil. DO NOT put water directly on to your condenser coil as this will lead to premature corrosion of the coil. Contact JD Cooling for more information on adiabatic cooling for condensers.
  • Consider an interim service during your peak season. A properly functioning plant will deliver much better crop quality and can provide massive running cost reductions.
Hydrocooler system