As experts in thermal transfer technology, 4d Air Products Limited supply coils to the Air Handling, Refrigeration, Process, Power Generation, Marine and Offshore Industries. Offering a full design and supply service, 4d Air Products Limited is the first stop for all of our customers. Whether it be replacement coils or a full design and manufacture of bespoke heat exchangers, 4d Air Products Limited offers quality, reliability and design expertise when it matters.