HVAC or Heating, Ventilation, and Conditioning are fundamental, closely-related functions in homes, offices, any other building architectural structures. Also known as climate control, the HVAC system is essential in maintaining comfort in most dwelling. Heating is essential in maintaining suitable room temperature, specially in cold weather, ventilation is owned by air movement and air-con controls both the heat and also the ventilation. Since these are integrated and centralized, the constant maintenance of their controls, systems, supplies and equipment essential. Pressure and temperature sensors and gauges are vital role in HVAC systems thus proper pressure and temperature calibration essential. Temperature and pressure calibration provide means of quantifying uncertainties in temperature and pressure measurement respectively, in order to optimise sensor and system accuracies. An HVAC system demands the process of calibrating anyone branch flows of the software. For each branch of the system, a damper is closed and flow values at the output of your prime mover and in the input belonging to the damper are measured. The damper is opened 50% and flow values are measured just as before. The flow through each damper 1 branch is calibrated in this particular manner, thus balancing the entire HVAC strategy. Generally, process calibrators tend to be for this as tend to be multi-function devices. Truly versatile process calibrators have the ability to make a precision measurement or generate an analog precision stimulus. They should have calibration that is traceable to national standards and possess a known accuracy or measure of calibration uncertainty. A good calibrator is capable of doing performing temperature calibration, DC Voltage and frequency calibration and also wide-ranging pressure calibration. Temperature calibration of HVAC systems is achieved by elevating or depressing the temperature sensor to a controlled temperature and measuring the corresponding change in its associated electrical parameter. The difference one of the measured parameter and an official reference probe is the calibration errors. In the truth of pressure calibration of HVAC systems, the instrument under test determines the calibration specs. Using a process calibrator, a controlled source, with a range slightly exceeding regarding the pressure instrument under test, is applied to look at the error successfully. Precisely calibrated temperature and pressure sensors and gauges mean well functioning and safe HVAC systems.