andrew20441
29-11-2010, 06:27 AM
Hi all
i am a mechanical engineer and trying to give a critique overview of an operating AC system in some serviced apartments....to be short, i am stationed in Asia and find all sorts of problems. Could someone help give a guiding hand to the beginning of this critique....
""Dear Sirs
The following report is to help highlight and explain to you the overall condition and effectiveness of the air-conditioning systems at the xxxxxx apartments. The report is by no means to apportion blame or direct personal responsibility for lack of maintenance and or poor workmanship. The report is subject to many external factors and data may not be concluded as being 100% accurate due to the nature of air-conditioning systems and the environmental conditions imposed on them, load conditions according to weather conditions. This report is a very simplified in comparison to what can be a very complex assessment. In addition the data provided is only to provide an overview of the system and cannot be concluded as being a definitive audit due to certain conditions not being met. An overall condition and assessment should be undertaken on each unit by using other parameters and tests which are excluded from the initial agreement, for example system contamination via compressor failure, audit of spare parts used and fitted within the systems, history, detailed pipe-work routes.
The Air-conditioning systems currently being used at xxx are by and large in poor condition due to many contributing factors. The main factors are highlighted below:
Service & maintenance (Correct tooling, Lack of systematic maintenance procedures, Fault finding procedures, Spare parts replacement)
Poor installation, lagging, pipe support
Poor design, location, size calculation
Client mis-use and incorrect operation usage
Other contributing factors
Service and maintenance procedures should follow manufacturers guidelines. The guidelines do not however take into account system location and therefore environmental factors that should be considered when assessing the maintenance programmes and schedules. Guidelines are a general framework only and is the minimum requirement only. All systems should be pressure tested and full operations tested at each maintenance scheduled.
Installation commissioning reports should be undertaken and used as the operation parameters to be referred to at each maintenance checklist to fully understand the deterioration of the system over time. By and large systems deteriorate over time unless of component failure. Therefore by using commissioning reports give us a margin to work to and the best operation parameters. This is by no means the full accurate measurement of a systems performance due to many other variables, but it is a very good indicator.
When maintenance is undertaken it is very important to follow strict procedures and use the correct tools for the job. By not using the correct tooling and procedures can produce the effect of a system failure. But in effect it could be due to tooling not being calibrated properly, charging manifolds are a prime example of this, especially bourdon gauges, thermometers.
Spare parts replacement is essential for good working air-conditioners. By leaving the replacement of parts too long whislt the system still operates can also have a knock-on effect for other parts as loads increase. For example, horizontal directional vanes in the closed position at an indoor unit can actually limit the unit and its effectiveness to dissipate the cold air forming on the evaporator. This would result in increased back pressure on the tangential fan. Sub-standard contactors that jar can also impose problems with compressor operation as would poor quality capacitors that are not at the appropriate value could impose fan operations to be slow to “pick up” It is therefore important to purchase the correctly rated parts for the units. Fitting of PTC probes and thermostat probes, vitally important not to create an indifferent resistance reading of these by means of “twisting” the wires together. The correct reading of temperatures is vital to the systems correct operation.""""
does this read ok..or make sense?
BR
Andrew
i am a mechanical engineer and trying to give a critique overview of an operating AC system in some serviced apartments....to be short, i am stationed in Asia and find all sorts of problems. Could someone help give a guiding hand to the beginning of this critique....
""Dear Sirs
The following report is to help highlight and explain to you the overall condition and effectiveness of the air-conditioning systems at the xxxxxx apartments. The report is by no means to apportion blame or direct personal responsibility for lack of maintenance and or poor workmanship. The report is subject to many external factors and data may not be concluded as being 100% accurate due to the nature of air-conditioning systems and the environmental conditions imposed on them, load conditions according to weather conditions. This report is a very simplified in comparison to what can be a very complex assessment. In addition the data provided is only to provide an overview of the system and cannot be concluded as being a definitive audit due to certain conditions not being met. An overall condition and assessment should be undertaken on each unit by using other parameters and tests which are excluded from the initial agreement, for example system contamination via compressor failure, audit of spare parts used and fitted within the systems, history, detailed pipe-work routes.
The Air-conditioning systems currently being used at xxx are by and large in poor condition due to many contributing factors. The main factors are highlighted below:
Service & maintenance (Correct tooling, Lack of systematic maintenance procedures, Fault finding procedures, Spare parts replacement)
Poor installation, lagging, pipe support
Poor design, location, size calculation
Client mis-use and incorrect operation usage
Other contributing factors
Service and maintenance procedures should follow manufacturers guidelines. The guidelines do not however take into account system location and therefore environmental factors that should be considered when assessing the maintenance programmes and schedules. Guidelines are a general framework only and is the minimum requirement only. All systems should be pressure tested and full operations tested at each maintenance scheduled.
Installation commissioning reports should be undertaken and used as the operation parameters to be referred to at each maintenance checklist to fully understand the deterioration of the system over time. By and large systems deteriorate over time unless of component failure. Therefore by using commissioning reports give us a margin to work to and the best operation parameters. This is by no means the full accurate measurement of a systems performance due to many other variables, but it is a very good indicator.
When maintenance is undertaken it is very important to follow strict procedures and use the correct tools for the job. By not using the correct tooling and procedures can produce the effect of a system failure. But in effect it could be due to tooling not being calibrated properly, charging manifolds are a prime example of this, especially bourdon gauges, thermometers.
Spare parts replacement is essential for good working air-conditioners. By leaving the replacement of parts too long whislt the system still operates can also have a knock-on effect for other parts as loads increase. For example, horizontal directional vanes in the closed position at an indoor unit can actually limit the unit and its effectiveness to dissipate the cold air forming on the evaporator. This would result in increased back pressure on the tangential fan. Sub-standard contactors that jar can also impose problems with compressor operation as would poor quality capacitors that are not at the appropriate value could impose fan operations to be slow to “pick up” It is therefore important to purchase the correctly rated parts for the units. Fitting of PTC probes and thermostat probes, vitally important not to create an indifferent resistance reading of these by means of “twisting” the wires together. The correct reading of temperatures is vital to the systems correct operation.""""
does this read ok..or make sense?
BR
Andrew