Compressor remanufacturer Thermacom has recently carried out a number of chiller refurbishment projects which has returned impressive savings for end-users in terms of both energy consumption and initial costs. It is also good for the environment as Thermacom’s Trevor Dann explains.
A CHILLER refurbishment project carried out by Thermacom has saved a staggering 35% to 60% of input energy so far.

Not all chillers can be retrieved from the scrapyard, but more units out there can be successfully restored than can’t and invariably can be so at a financially rewarding price when compared with new.

So what can be done to enhance an unreliable, badly controlled, leaky rotten old chiller?

Primary works could include condenser coil renewal, screw compressor conversion, refrigerant gas conversion R22 to Isceon 29/59, and refrigeration and control system upgrades.

Secondary works could include: refrigeration system control valves; compressor switchgear; compressor overhaul (where conversion is not undertaken); refrigeration system integrity; control panel wiring condition; condenser fan service; refrigeration system set-to-work procedures; and unit cleanliness/paintwork. Some chillers may require attention in all areas, others just some.

In environmental terms several factors need to be balanced together to provide the basis of a decision to simply renew or upgrade chillers. Each project is different and an individual assessment of the environmental and cost benefits is required.

Energy saving

In the case of HCFC plant a typical drop-in replacement such as Isceon 29 will typically save 5-8% for a commensurate cooling load. The renewal of old, dirty and corroded condenser will improve heat rejection, reduce the upper operating level (head pressure) with a consequent reduction in compressor loading and draw current of, typically, 10-20%.

Replacing inefficient 1920 - 1970 piston technology with new and quieter second generation screw compressors improves volumetric efficiency, and reduces input power by around 10 to 15%.

Improved control

Many systems are simply poorly controlled. Power is wasted in stopping and starting compressors and fans and having multiple chillers badly controlled can also be very wasteful of energy. On many sites, simple modifications to the method of control can reduce energy consumption by as much as 10-15%.

Improved reliability

Reducing plant failure and call-out frequency will reduce direct maintenance costs. In addition, reliable plant means improved productivity for the task to which the cooling plant is assigned. Any chiller upgrade project faces certain technical and legislative limitation. In most cases upgrades would be highly effective, but technical limits do exist and so does forthcoming legislation. Ultimately new solutions do not always offer the most effective choice. It is a huge shame that perfectly serviceable equipment is condemned through lack of knowledge.

ThermaCom

0118 950 0606