Welcome to Crystal Sigma Ltd London. Crystal sigma is a leading specialist in refrigeration, ventilation, heating and plumbing, electrical services, air conditioning in London, for the home and the business place. Our services: Installation of Air conditioning systems (Split & VRV/VRF Systems) Installation of Air ventilation systems Installation of Climate control systems, Heat recovery systems Plumbing service Refrigeration repairs service We have a very high standard of work with many happy customers over the years. Contact us with any enquiries.