January Newsletter 2012 announcing the new Bacharach fixed range of gas monitors which can now be ordered through Murco in Dublin.

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October Newsletter 2011 announcing the new appointments at Murco and contact details for clients.

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1. Type of detection. Choose which approach to gas sensor location you require: Perimeter Detection, where sensors are placed on the outskirts of the area being monitored, and/or Point Detection, where sensors are located as near as possible to the most likely source of potential leakages such as compressors, expansion valves, mechanical joints or cable duct trenches.

2. Number of sensors. There are no UK laws on sensor coverage. However the British Standard is 36m² per sensor in a machinery room, or 50m² if there is a discernible air flow. In refrigerated spaces, like cold stores with evaporators, coverage is increased to 50/100m² due to strong air movement. This also applies to car parks with ventillation or air conditioned spaces with good air flow. When selecting the number of gas sensors your installation requires, don’t over-economise. A few extra sensors could make all the difference if a leak occurs.

3. Cross sensitivity.  Sensors are designed for maximum sensitivity to individual gases, however false alarms may be caused by the occasional presence of sufficiently high concentrations of other gaseous impurities. This might occur in plant rooms where maintenance involves the use of solvents or paint fumes, fruit ripening/storage facilities where accidental gas migration occurs, or confined rooms with heavy localised exhaust fumes from engine driven forklifts.

4. Gas Density. Senors used to detect a gas heavier than air (butane, propane, LPG or ozone) should be located near ground level, while gases lighter than air (hydrogen, methane or ammonia) require higher positioned gas sensors. Remember to take into account room ventilation, air temperature and gas density.

The correct positioning of gas sensors during the installation process is of paramount importance. If a gas leak does not reach the sensor then no alarm will be raised, so carefully selecting the right location for the sensors is crucial. Consult with Murco’s technical department for further advice.

Here are seven ways your business can better maintain its refrigeration systems while reducing energy consumption using gas monitors.

1. Inspect – Regular inspections of your refrigeration systems, especially checking for potential gas leaks, will allow you to notice problems early on so you can take action. Look for ice build-up on evaporators, debris on condensors, broken fans etc. Bubbles in sight glasses can indicate a refrigerant leak. Make sure your gas monitors are in good working order. If you’re familiar with your refrigeration system you’re more likely to recognise when it may need attention.
2. Maintain – Refrigeration systems need regular maintenance to ensure they continue to perform well. Setting up a maintenance contract with an experienced gas monitors contractor will ensure your refrigeration plant is safe, efficient and reliable and will also help reduce costs in the event of breakdowns or emergency service calls.
3. Control – Get to know how your refrigeration system works. Different refrigeration systems have different controls. Understanding your system functions will make maintaining it that much easier.
4. Reduce the load – Only refrigerate items when needed. When it is required, keep refrigeration at the highest possible temperature to reduce the load on the refrigeration system and cut energy costs.
5. Cut your losses – Refrigeration is expensive. Contain it as much as possible. Keep cold room doors closed, seals in good repair, ensure insulated rooms are air tight and invest in good pipe insulation to avoid lost cooling capacity and reduced compressor efficiency.
6. Better housekeeping – Don’t overstock cabinets, keep air grilles clear, close doors, blinds and night covers and maintain door seals.
7. Good design – If you are investing in a new refrigeration system, choose a high-efficiency option which will have a long life span, save energy, and have long-term low running costs.

In addition to keeping a well maintained refrigeration system, make sure to install refrigerant gas monitors for optimum safety. Contact Murco for more information about your refrigeration system requirements.

Sensors must be protected from weather conditions such as rain, snow and other precipitation. For example, heavy tropical rains can splash more than 30 centimeters off the ground so it is imperative that sensors for heavy gases such as liquefied petroleum gas (LPG) should be raised high enough to avoid becoming ineffective from rain.

Gas sensors should also be located downstream of prevailing winds; taking into account the wind effects caused by buildings, tanks and other obstructions.

Outdoor locations requiring gas leak detection solutions

The areas requiring the most protection in outdoor areas of an industrial plant would be around gas boilers, compressors, pressurised storage tanks, cylinders or pipelines, vent pipes and pressure relief valves. The component parts most vulnerable to outdoor conditions are valves, gauges, flanges, T-joints, filling or draining connections, et cetera.

Remember that gas can collect in roof voids, pits and trenches and, if possible, anticipate where maximum concentrations of main airflows are likely to occur.

Gas sensors should be positioned slightly back from any high-pressure parts, such as pressure relief valves, to allow gas clouds to form. Otherwise any leakage of gas may pass by in a high-speed jet motion and fail to be detected by the sensor.

In the case of outdoor air conditioning units, such as air-cooled chillers or the outdoor unit for VRV/VRF systems, mount the gas sensor so as to monitor the airflow to the extractor fan. For large units also place a gas leak detection equipment could be placed inside the enclosure just under or adjacent to the compressors.

Remember that care should always be taken to position the gas sensors in a way that facilitates easy access for maintenance, repairs or calibrations, and weatherproof sensors should always be used for unprotected outdoor areas.

Contact Murco for further recommendations on correct outdoor gas sensor installation guidelines or for advice on Murco’s range of gas leak detection sensors.

The use of regular monitoring aids and gas detectors is recommended in assessing the effectiveness of your refrigeration systems, addressing any developing faults, and implementing a course of action to prevent potential malfunctions.

Monitoring refrigeration systems with gas detectors can be effectively and efficiently carried out in-house at minimal cost.

Research – Find out what monitoring is done by your engineers and maintenance contractor, what instrumentation is available for your plant, eg. to measure pressures, temperatures, power etc. and find out how often it’s calibrated.

Implement routine – Decide on a suitable monitoring routine using gas detectors and establish a monitoring frequency for your refrigeration plant. Monitoring frequency will depend on the size and complexity of the system and the energy usage of the refrigeration plant. Good practice would be to:

• Log suction and discharge pressures
• Record temperature inside the cooled space and ambient temperature
• Record kWh, power and amp meter readings
• Keep a log sheet of key data and update regularly

Analysing data – Establish a system for analysing any key trends in monitoring data. Good practice would be to plot power consumption against an operating parameter such as outside temperature or product throughput in order to identify periods of high energy consumption. Changes in recorded data should be carefully examined.

Pressure gauges – Changes in pressures and temperatures can indicate a problem. A drop in suction pressure could suggest refrigerant leakage. Ensure you have refrigerant leak gas detectors installed.

Temperature check – Monitoring the temperature inside the cooled space will show you whether it is over-cooling or if cooling capacity has been reduced.

Computerised monitoring – You may want to introduce a computerised monitoring system with automatic fault alarms if a refrigeration fault could lead to significant stock losses, production problems or energy wastage. A refrigeration specialist can assist in advising the appropriate level and frequency of monitoring for your system and gas detectors to use.

Refrigerant leak detection – Remember to install refrigerant sensors near cooling systems to detect any leaks and deal with them in a timely manner.

Contact Murco for information on refrigerant leak detection and advice on monitoring your refrigeration systems.

Understanding that refrigerant leakage will not only cause substantial financial losses for businesses but may also cause significant damage to the environment through the release of hydrofluorocarbons (HFCs) into the atmosphere, has led to urgent action to reduce leakage from refrigeration systems.

REAL Zero initiative helps UK industries strive towards to a zero refrigerant leakage rate

REAL Zero – a new UK initiative developed by the Institute of Refrigeration and funded by the Carbon Trust – is designed to help industries to work towards a zero leakage rate.

The programme aims to help businesses develop a clearer understanding of where and why leakages occur and how to prevent them using gas detection devices.

If a refrigerant leak is not promptly repaired it will start to effect system efficiency and the energy costs for the system will increase. Eventually the refrigeration system will no longer be able to provide enough cooling which could lead to massive loss of product. The longer a leak is left for repair the higher repair costs, product replacement and additional energy usage.

Regulations already place responsibility on companies that use HFC refrigerants, including record keeping and gas detection. The REAL Zero initiative assists businesses with this responsibility.

By making sure you have a well installed and maintained refrigeration system you will not only be reducing the risk of refrigerant leakage, but you can also save potentially hundreds of pounds on repair and replacement costs and up to 15% savings on energy costs.

Payback time for installing a well maintained refrigerant system with adequate gas detection equipment is typically two to three years for small leaks, and less than a year for a large leak. You will also save the cost of replacement refrigerant gas.

By ensuring you have a reliable gas detection system you can help your business achieve the zero gas leakage target.

For further information about the REAL Zero initiative visit www.realzero.org.uk or contact Murco for more information.

Undetected gas leaks can have heavy financial implications.

Where the gas that may leak is the primary revenue source for a company, such as where they produce or distribute the gas, the expense of a leak is obvious but where the gas is a supplemental factor the cost is not so clear.

In the case of a refrigerated warehouse where an adequate gas detection system has not been put in place or has been allowed to fall into disrepair a leak may continue for an extended period. Energy costs increase as the refrigerator motors work harder to pump the limited refrigerant. If certain perishables are stored in the refrigerated warehouse they may be spoiled by the leaking refrigerants leading to a huge loss of stock. The cost of refilling a large refrigeration unit with refrigerant gases can also be very expensive depending on how long the leak has gone undetected.

An inadequate or poorly maintained gas detection system may not meet UK health and safety standards. A heavy fine can have a damaging effect on the growth of a company. A closure by authorities due to inadequate gas detection can be even more harmful to a companies resources as well as endangering the lives of staff and potentially the public.

Many European wide directives on environmental damage have been incorporated into UK legislation. This means that heavy fines can be imposed where gases that are damaging to the environment are released. In particular certain refrigerants such as CFC’s can bring large penalties if they are not detected upon release.

Many industries use, store or manufacture combustible gases. These are gases that will explode upon contact with an open flame. Gas detectors are used in the presence of these gases so that, should there be a leak, people in the vicinity can be alerted and escape before the gases explode. Gas detectors are also generally connected to a control centre that can establish where the leak is and cut off the supply of gas to that area.

Liquefied petroleum gas is a combustible gas that is commonly used for heating applications as well as a fuel for cars. It is one of the gases that is coming to replace CFC’s in refrigeration units as CFC’s are phased out due to the damage they are believed to cause to the ozone layer. It is a mixture of gases that is typically made mostly from propane or butane. Odorants are usually added to the mixture for gas detection purposes.

Pure propane is commonly used to fuel gas barbeques and home central heating systems. This makes it a common house hold fuel and as such is stored in depots around the country side. Since it is highly combustible gas detectors are installed wherever it is held in large quantities.

Hydrogen has a wide variety of uses including amongst other things in the processing of fossil fuels and the production of ammonia. It forms explosive mixtures with air at anywhere between 4 and 74% concentration. Since it is so combustible gas detectors are used where hydrogen gas is stored or produced.

The main component of natural gas is methane. It is used as a fuel either for electricity generation in a gas turbine or for heating in a central heating system. Apart from its high combustion levels another reason for using gas detectors with methane is its high potency as a green house gas.

In order to monitor the concentration of gas in an area and detect gas leaks a fixed gas detection system is typically installed. A system such as this prevents harmful gases damaging the environment, saves on operational costs and most importantly maximises the safety of staff and the public alike.

There are two types of fixed gas detection. One is using remote sensors, the other uses air sampling systems. Remote sensors have a higher level of accuracy than air sampling systems and they also operate by continuous monitoring.

Remote fixed gas detection systems employ monitors located around a building which connect back to a central monitoring system. The remote gas sensors continuously monitor the air in their vicinity. Each remote monitor works independently of the others meaning that if there is a failure in one of the monitors other monitors and the central unit continue to detect gas leaks.

There are a number of draw backs to using an air sampling system in place of a fixed gas detection system. Air sampling systems only test the air at intervals meaning that the monitoring is not continuous and therefore less reliable.

The gas analyzer is centrally located. Narrow ducts carry samples of air from the specific locations to this central analyzing unit. These kinds of fixed gas detection systems require a lot more maintenance due to problems such as pipe blockages.

Because there is only one unit detecting for gas leakages the entire system is dependant on the continuous operation of this single unit. If this unit fails no gases will be detected.

Often a single room may require several different types of gas to be monitored at once, for example ammonia and carbon dioxide. Remote sensing fixed gas detection systems can easily be set up to detect many different numbers of gasses.

Murco gas detection manufactures and designs fixed gas detection systems that are customised specifically to their customers needs. Murco offers fixed gas detection solutions for a variety of industrial, commercial and municipal industries. To find out more about Murco’s fixed gas detection systems visit  http://www.murcogasdetection.com or call on +353 1 284 6388