ADX Technology

Colmac Coil has pioneered the use of low charge direct expansion in low temperature industrial ammonia refrigeration applications. This new technology reduces the first cost of installation while significantly reducing the ammonia charge required on the site. It has been proven in recent installations that using ADX® in industrial refrigeration systems produces additional benefits including: faster defrosting, effective operation at multiple temperature levels (convertible rooms), good response to changes in load, fast restart after power failure, and simplified maintenance and operation through elimination of recirculation pumps. Because of the reduced ammonia charge on site and in the occupied spaces, regulatory burdens can be reduced, and work spaces made safer. ADX® Low Charge Ammonia - inherently safer technology.

This proven technology is being successfully used in multiple locations around the world.


Colmac Coil is pleased to announce the next edition of the DX Ammonia Piping Handbook. This handbook is intended to guide the reader through the process of successfully designing and implementing DX Ammonia from +50°F to -50°F.

The fourth edition of this valuable technical resource includes updated and expanded system configuration descriptions as well as new P&ID style piping diagrams.

Colmac Advanced DX Ammonia is covered by a number of USA and foreign patents including:


Packaged liquid subcoolers are offered in three sizes, up to 100, 300 & 700 evaporator tons depending upon the system liquid flow requirements. These units are built around fusion welded compact plate heat exchangers for a minimum ammonia charge and optimum heat transfer efficiency. It will be pre-piped and mounted on a base frame. The system liquid lines will be sized for a velocity of less than 4 ft/sec.  

Detailed selection information can be found in the Engineering Bulletin, Engineering Specifications and installation and maintenance information is explained in the IOM.