somebozo
ELITE MEMBER
- Joined
- Jul 11, 2010
- Messages
- 18,872
- Reaction score
- -4
- Country
- Location
We had a project needing several hundred air-conditioners so we set about to source it our self as this could potentially save a sizeable chunk of money. So laptops started and google fired we started searching for manufacturers on various trade websites. After finding tens and sorting them down to few, the fun started as we started demanding documents, reports and explanations from supplier. Surprisingly many suppliers simply went silent opting to stop replying emails or the salesmen just quit their jobs as per explanation. Leaving only two contenders to compete with one of them bring the Top-3 ODM of China. Air-Conditioners are complex machines with every component needing the right consideration for overall performance of the system
The import of air-conditioners in Saudi Arabia requires SASO and GMark compliance as well as energy star rating. And the suppliers sending their SASO compliance documents was impressive nonetheless in the beginning. But , so are the findings.
The import of air-conditioners in Saudi Arabia requires SASO and GMark compliance as well as energy star rating. And the suppliers sending their SASO compliance documents was impressive nonetheless in the beginning. But , so are the findings.
- Having SASO and GMARK Compliance does not mean anything. Same is true for any ISO, TUV, BV, SGS, etc certifications. The Chinese have mastered the art of gaming the system. These certificates are issued on the basis of samples provided and there is no feasible mechanism to quality test each and every unit coming out of production line by the certification authority. A leverage very well exploited by the manufacturers. Also note that all quality certifications are self-policing means the manufacturer makes a voluntary commitment to abide by them. The certification agency has no mechanism to enforce this compliance.
- BTU theft is the most common type of fraud in Chinese air-conditioners. For example we request an 18000 BTU unit but when the actual SASO certificate copy was sent to us it only showed the unit rated for 17400 BTU. The explanation given was that SASO allows for 5% variation but the principles of good engineering demand that this variation exists only on the positive side. For example an 18000 BTU unit with a test report of 18200 - 18700 BTU is acceptable but the net BTU capacity should never fall below the advertised capacity.
- We were impressed by the brands of compressors offered such as GMCC, Hitachi, Panasonic, Sanyo but things turned sour as soon as we started cross-checking their model numbers against technical cataloges. Air-conditioners are relational machines and their performance is impacted by various ambient factors. Therefore, there are multiple standards to rate their performance. Higher performance air-conditioners destined for Saudi market would take 55C as an outdoor ambient to calculate the net operational capacity.
- It is important to demand technical specification in detail on every component almost as if you are reverse engineering something. Compressor, air-flow of fans, fins per inch etc etc. And then have a competent refrigeration engineer reverse calculate everything to prove the capacity for you. There are infinite combinations possible to game the system and produce the desired results on test report but the actual operation will suffer.
- Stealing in the fins per inch (FPI) density would rob efficiency from the heat exchanger making compressor run longer hours than needed and hiking up the electricity bill.
- BTU is not everything but rather a relational calculation of all components and performance parameters. Pay attention to the evaporator temperature listed. A unit specified for 7.2C evaporator temperature would provide a higher BTU rating for the same size of compressor but it would be less efficient at cooling against a model specified with 4.0C because as delta T increases the heat transfer efficiency also increases. The standard evaporator temperature for most high quality air conditioners is 4.0C.
- An air-conditioner phase changes liquid to gas inside copper tubes to produce the cooling effect therefore purity and quality of copper tubes and aluminum fins used in a unit is crucial. Steer clear from anyone refusing to answer these questions. Units made with poor quality copper and aluminum have worst efficiency ratio and will hike your electric bill.
- No matter what happens do not opt for pre-charged units. China is not an origin for high quality refrigerant gasses and there is no way to proof what the factory put in their. A low quality refrigerant will sooner or later blow up your compressor.
- In a nutshell there are less than handful of real high quality air-conditioner OEM in China such as Haier, Gree, etc and any real ODM will not sell you anything out of their factory. So far my conclusion is that it is impossible to buy high quality and performance verified air conditioners from a factory out of China. Thailand and Japan are more promising prospects and Thailand has a world renowned air-conditioner manufacturing base.
Last edited: