We provide comprehensive design support and HVAC design services for all stages of the design process, from concept, schematic, design development, tender to construction stages. Design basis reports, heat load, piping and other calculations.XS CAD provides the following range of HVAC mechanical systems design services, drawings and documents: Energy related design – including gas, oil, renewable and solar design and systems.Heating, ventilation and air conditioning design (HVAC) for environmental control.In essence, HVAC mechanical systems design include: HVAC mechanical system design refers to the design of elements of infrastructure, plant and machinery and tools and components of heating, ventilation and air conditioning (HVAC) and their system design.