Hawke’s Bay Refrigeration Energy Efficiency And Reliable Refrigeration Presented By Scott Klem

Introduction Scott Klem Local Refrigeration Service Provider Hawke's Bay Refrigeration (2005) Limited is a Hawke's Bay owned and operated company specializing in all aspects of domestic, commercial and industrial refrigeration. Hawke’s Bay Refrigeration has been in the Refrigeration, Heating Ventilation and Air Conditioning (HVAC) industry since 1992. We design and install refrigeration and air conditioning systems, and provide maintenance and service contracts to suit our client’s requirements. Our company provides for a wide range of industries, from office and home air conditioning, to orchard cool stores, controlled atmosphere rooms, meat processing plants and winery refrigeration systems. Like WorleyParsons we don’t have any allegiance to any particular brand Carried out Massey University Courses on Cost Effective Refrigeration

Improve Efficiency of Your Existing System Typically the reasons for inefficient refrigeration system performance are: poor design, poor control and poor maintenance. The latter two are relatively easy to fix, while the first reason is likely to require capital investment. To improve the efficiency of your existing plant without spending large amounts of capital, we recommend: Ensuring a whole system approach is used Regular preventative maintenance Glycol as a cooling medium Staff are familiar and trained with the operation of the plant Variable speed drives on condensor, evaporator fan motors and pumps Electronic expansion valves Optimize your suction and discharge pressures

Ensuring a Whole System Approach is Used We recommend when looking at your system that you take in consideration all aspects. For many businesses, refrigeration systems consume large amounts of electricity, thereby contributing greatly to operating costs. Improvements to technical aspects of operations have the potential to reduce energy use by up to 40%, whilst simple improvements in operational practices can reduce energy use by 15%.

System Considerations Ensure a whole-system approach is used. Design for year-round efficiency. Avoid heat gain in the system by using ambient pre-cooling of product, adequate insulation, shading, minimising air infiltration and so on. Design for part-load performance using VSDs on compressors or efficient control of multiple compressors. Use of refrigerant storage in the system to meet demand peaks. Opportunities for heat recovery. Layout of product within the cooled space to optimise exposure of product to cooled air. Pipe layout to minimise run lengths and ensure product flows are smooth.

Regular Preventative Maintenance We recommend that you get your system fully checked and cleaned at the start of each season and then either quarterly or 6 monthly checks depending on your equipment. These checks should include the following: Cleaning of condensor coils Cleaning of evaporator coils Replacing noisy fan motor bearings Refrigeration leaks Glycol percentage checks Glycol is clean and free of air Door seals are in good condition with no gaps Room insulation Check for moisture or ice forming on the outside of cool store Clean Glycol strainers Compressor sets are efficient and effective Check suction and discharge pressures are set correctly

Staff are Familiar and Trained with the Operation of Plant Your onsite staff need to be trained and familiar with the operation of your plant as this varies throughout the year. Small plant adjustments to suction pressures, discharge pressures and defrost setting can save up to 15% of your energy costs. This is especially important during low peak loadings.

Variable Speed Drives on Condensor, Evaporator Fan Motors and Pumps Variable speed drives should be considered when your plant is not running at its full load. A general rule of thumb for fans is that if you run your fan at 70% capacity you can save 20% of your energy cost without affecting performance of the system when at part load. IE if you run your fans at 35hz you can save 20% power costs. Also VSD’s on pumps can be a great energy saver when the pumps are not at full load. We recently had a system were we had 4 x 11 kw Glycol pumps constantly running. We installed a pressure transducer and VSD on the lead pump and cycled the other pumps on and off as required . This controlled the system pressure accurately and allowed the other 3 pumps to cycle off. The power savings were approximately $70 per day.

Electronic Expansion Valves One of the main advantages in using EXV technology is the energy saving achievable due to improved efficiency of the refrigeration cycle. The possibility to operate at low condensing pressures, as well as precise superheat control, allow considerable energy saving: the advantages have been proven and validated in the field, in both refrigeration and air-conditioning applications, and guarantee extremely short payback times compared to standard mechanical technology.

Glycol as a Cooling Medium Glycol needs to be clean Free of air and contaminants Correct percentage Types of glycol Mono ethylene Mono propylene Specific heat capacity (The amount of heat required to raise a kilogram of any substance by 1°C) Correct flow rates

Removing Air from Glycol System is a Priority to: Save Money: lower energy bill less maintenance longer lifetime Optimum Water Circulation Protect Valuable Components Improved Heat Transfer

DEAERATION Free air (Automatic air vent) Microbubbles (Microbubble Separator) Dissolved Air (Pressure step deaerator)

Conclusion In conclusion I believe the most important aspects to make your plant more energy efficient are: Regular plant maintenance Optimising your current temperature settings, compressor suction and discharge setting Investing in VSD control for part loads Ensuring your glycol system is clean and free of air.