Specifications include, but are not limited to: on-call heating ventilation and air conditioning contractor to provide HVAC maintenance and repair services. The selected contractor would have the experience, knowledge, and skill to install, repair, alter ,recharge, add to, or design air filtration systems and HVAC (heating, ventilation, air conditioning) preventive maintenance and repair for various buildings/facilities at the City of Laredo. Preventive maintenance and repairs may include, but not be limited to, pneumatic control systems, electronic control systems, digital control systems, industrial chillers, commercial size boilers, and air handling units. The successful vendor will be responsible for providing labor, supervision, materials, equipment, transportation, service, and the shop facilities necessary to perform high quality work.