Search results
Results from the WOW.Com Content Network
Mean time to repair (MTTR) is a basic measure of the maintainability of repairable items. It represents the average time required to repair a failed component or device. [ 1 ] Expressed mathematically, it is the total corrective maintenance time for failures divided by the total number of corrective maintenance actions for failures during a ...
An enthalpy–entropy chart, also known as the H–S chart or Mollier diagram, plots the total heat against entropy, [1] describing the enthalpy of a thermodynamic system. [2] A typical chart covers a pressure range of 0.01–1000 bar , and temperatures up to 800 degrees Celsius . [ 3 ]
The depleted air cylinders within the breathing apparatus must be replaced and refilled throughout the incident. [2] The air and light unit can refill the cylinders while in the field using an onboard air compressor and cascade system. [1] It also carries a supply of spare air cylinders.
The study of the behavior of air-water vapor mixtures. Water vapor plays an important role in energy transfer and human comfort in HVAC design. rooftop unit (RTU) A packaged unit that controls both heating and air conditioning. An air handler typically refers to a unit that provides a fan to support either heating or cooling. radiant ceiling panels
Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced each hour.
An air purge heating unit is used to ensure that the purge air remains at a temperature above the acid dew-point. This temperature is typically around 20 °C/68 °F. [2] If temperatures are below this point, the controls will be corroded by condensation of compounds in the flue gas. Heated air ensures that controls are dry during startup. [3]
These motors are sometimes called DC motors, sometimes EC motors and occasionally DC/EC motors. DC stands for direct current and EC stands for electronically commutated.. DC motors allow the speed of the fans within a fan coil unit to be controlled by means of a 0-10 Volt input control signal to the motor/s, the transformers and speed switches associated with AC fan coils are not required.
A water flow test, also known as a hydrant flow test, [1] is a way to measure the water supply available at a building site, usually for the purposes of installing a water based fire protection system (fire sprinkler system).