Air Conditioning Mobile Service Engineer specialising in maintenance , repair and servicing of vehicle air conditioning covering Shrewsbury, Telford, Shropshire and Mid Wales areas.
FGAS 2079 class 1 trained mobile service engineer travels to you to diagnose the fault and fix your car truck or tractor air conditioning system. Car Van Minibus Truck Tractor and Mobile Plant Cab Air Conditioning and Refrigeration.Telephone 01743 884888 www.autoelectrics.net
Vehicle air conditioning systems work by absorption of heat from the cabin area providing cooling effect and transfer of heat to the exterior allowing travel in comfort.
An efficient vehicle air conditioning system reduces high temperatures in the passenger compartment by best cooling effect if the air vent system controls are set to recirculation mode and windows left closed allowing chilled air for a cooler driving climate and fresh, more comfortable, travel environment.
Enhance driver and passenger safety by maintaining a comfortable cabin temperature in hot working conditions to reduce risk of heat exhaustion.
Cab temperature control improves working environment for operators of mobile plant increasing comfort and reducing fatigue.
Maintain vision by keeping the windscreen demisted. Some systems can reverse the flow of refrigerant to provide heating as well as cooling.
Filtration of air entering the passenger compartment cab reducing dusts and pollution
Dehumidifying - Drying of the air circulating in the passenger compartment
Enhancement of vehicle security allowing windows to remain closed in hot weather
Supply of air conditioning compressors, switches & components, heaters, heater blower fan motors, repairs to : Vans * HGV Trucks * Minibuses * Coaches * Ambulance * Excavators * Construction equipment * Quarry plant * Agricultural machinery * Marine * Motorhome
Vent temperature : Warm air blowing from cabin vents when the air conditioning system is operating indicates that the aircon system needs repair or service. If the air conditioning is working properly air from vents will feel icy cold.
Air conditioning is a pressurised system. Refrigerant can be lost from the vehicle air conditioning system due to leaking or corroded pipework, seals, or components.
The condenser can be a common point of failure due to its location at the front of the vehicle and possibility of impact damage.
Receiver dryer units mounted in areas subject to road spray can be particularly vulnerable to corrosion and leakage.
Refrigerant leakage from vehicle air conditioning evaporator is less common but can be difficult to detect and complex to repair because of location behind vehicle dashboard.
Symptoms of air conditioning refrigerant loss from a vehicle climate control system may include:
Hissing noise of gas escaping can indicate a refrigerant leak, though most leaks are less obvious. Refrigerant should be recovered from the system as soon as possible for environmental reasons.
Warm air blowing from cabin vents.
Failure of the air condtioning compressor to operate. Low refrigerant pressure sensed by the pressure switch may prevent engagement of the vehicle aircon compressor electric clutch.
Loss of refrigerant can also result in loss of the refrigeration oil which lubricates the air conditioner compressor leading to subsequent failure.
Marginal refrigerant gas loss can occur over time by permeation through hoses. Vehicle manufacturers generally recommend that an automotive air conditioning system has a refrigerant recharge every two years.
System blockage may occur where components have failed or pipework is damaged or kinked. System blockage due to ice can occur. TXV failure or blocked orifice tube may cause abnormal system pressures.
Vehicle climate control systems can have complex wiring and electronic control which may require computer aided diagnosis to read or clear fault codes which may prevent air conditioning system operation.
A typical electronic climate control system may monitor external ambient and internal cabin vent temperatures, refrigerant pressure and flow, also monitoring and controlling compressor engagement, rotational speed and operation of blower fans.
Strict Legislation applies to the servicing of Vehicle Mobile Air Conditioning and Refrigeration Systems. See(MAC directive) of EC F-Gas (Fluorinated Gas) Regulations also see http://www.defra.gov.uk/environment/air-atmos/fgas/sectors/mobileaircon.htm for more details.
Persons recovering refrigerant have a legal requirement to be F-gas trained and qualified as a refrigerant handler to meet the requirements of 2014 EC regulations and also company registered see Guidance notes
more information about F Gas regulations and guidance is available from Gluckman Consulting see IS6 and IS22. Updated F Gas regulations apply from 1st January 2015 (EU reg 517/2014).
A variety of refrigerants have been used by manufacturers in vehicle mobile air conditioning (MAC) applications with different refrigerant types and systems requiring a variety of service equipment. Refrigerants are compared by Global Warming Potential (GWP). Legislation is aimed at gradual phase out of environmentally damaging refrigerants in favour of low GWP solutions.
R12 is a CFC refrigerant which was used on older vehicles but was banned in the 1990s due to its damaging environmental effects.
R134a is a HFC refrigerant(GWP 1430) and probably the most common refrigerant currently found in air conditioning systems of vehicles sold up to 2017. Only Fgas certified personnel can legally recover R134a from a vehicle air conditioner.Facilities for service and repair of vehicle R134a air conditioning systems on site (where component access allows) include:
Environmental legislation has forced manufacturers of vehicles type approved since 2011, and all new vehicles sold after 1st January 2017 to use low GWP refrigerants below 150. HFO R1234YF refrigerant (GWP 4) which has many environmental and cooling benefits over R134a including a lower GWP rating. Certain manufacturers have raised concerns about the use of 1234yf due to potential flammability.
Vehicle air conditioning systems using R744 Carbon Dioxide (GWP 1) are being developed by some manufacturers. R744 is already in use in stationary refrigeration applications and operates at extremely high pressures (up to approx 170 bar). Dry ice can be formed within systems causing blockage. Carbon dioxide leakage in to vehicle interior may be detrimental and cause nausea, to overcome this a Carbon Dioxide sensor is fitted to the vehicle interior.
HFO R452a is a blended (Zeotropic) refrigerant used in Commercial vehicle transport refrigeration systems.
Moisture causes problems with air conditioning system components because;
Refrigerant recharge involves recovery of any remaining refrigerant from the air conditioning system to minimise environmental damage before any service maintenance work is completed.
Leak detection methods include:
After refrigerant recovery, the air conditioning system is placed under vacuum to remove air and moisture. During a vacuum hold test the system is locked off whilst under vacuum and monitored for a time period to see if vacuum is lost indicating an air leak nto the system, or potential refrigerant leak. Most automatic refrigerant recovery machines used in garages use this method of leak test before refrigerant recharge is allowed. Refrigerant leaks may not show when the air conditioner system is under vacuum but only show by pressure test.
After refrigerant recovery, the air conditioning system is pressurised with Nitrogen gas. The system is locked off whilst under pressure and monitored for pressure loss over a time period. Loss of pressure indicates a leak.
An electronic device sensitive to refrigerant is used to sense leakage by passing over system components and air vents.
A quantity of UV dye may be introduced into the vehicle air conditioning system. Should a leak occur, the UV dye will glow when under UV light.
Restricted component access can make leak detection on vehicle air conditioning systems difficult and complex to repair.
The only effective cure for a refrigerant leak is a repair or component renewal.
We welcome enquiries.
Useful links :