Some of the most asked technical Interview questions in Indian market for HVAC Design Engineer profile are discussed here. 1. What are the major components to be considered during heat load calculation? Answer: All the sensible & latent heat gain to be considered while calculating heat load. Major heat load components are Solar Heat Gain … Read more
A water level in the cooling tower has to be controlled & maintained by Makeup water in order to account for loss of water due to evaporation, blow down & mechanical carryout of water droplets(drift) during operation of cooling tower. Significance of each parameter is mentioned below with simple calculation of makeup water quantity requirement. … Read more
Cooling load estimation or Heat load calculation is the most important & primary step in any HVAC system design. In this article we will discuss important components that has to be taken into account while calculating Heat load for any space. The total heat required to be removed from the space in order to bring … Read more
NPSH stands for Net Positive Suction Head and is a measure of the pressure experienced by a fluid on the suction side of a centrifugal pump. The difference between inlet pressure and the lowest pressure level inside the pump is called NPSH. NPSH is therefore an expression of the pressure loss that takes place inside the first … Read more
Variable flow primary pumping systems utilize a variable capacity cooling system and a variable flow water pumping system to modulate cooling and water flow to meet chilled water needs and save operating energy costs. Cooling capacity is modulated with variable capacity compressors based on the desired leaving water temperature. Water flow is modulated with VFD … Read more
SHF,RSHF & GSHF are elements used in heat load calculation & which affects the psychrometric properties of the air. SHF – Sensible Heat Factor The thermal properties of air can be separated in to latent & sensible heat. The term sensible heat factor is the ratio of the sensible heat to total heat, where the … Read more
Bypass factor is the function of the physical & operating characteristic of the conditioning apparatus. It represents that portion of the air which is considered to pass through the conditioning apparatus completely unaltered. The physical & operating characteristic affecting the bypass factor are as follows: A decreasing amount of available heat transfer surface (i.e. less … Read more
Apparatus dew point is the effective coil surface temperature when there is dehumidification. This is the temperature to which all the supply air would be cooled if 100% of the supply air contacted the coil. When the air is to be cooled & dehumidified from t1 to t2 condition, the cooling coil has to be … Read more
If you have worked in chiller industry, you might have come across this terminology. In this article we will discuss the significance of Chiller surge & how to avoid it. General refrigeration circuit & flow First take a look how refrigerant moves along the component of refrigeration circuit. In normal operation low pressure refrigerant vapors … Read more
What is Fouling in Heat exchangers? Accumulation of undesirable materials(deposits) on Heat exchanger surfaces. Undesirable materials may be crystals, polymers, inorganic salts, biological growth, corrosion products etc. This Phenomena of rust formation & deposition of fluid impurities is called fouling. Depends significantly on the operating conditions. Effects Of Fouling Affects Heat Transfer & Flow. The … Read more