Larsen & Toubro Limited Assistant Manager Mechanical Interview Questions and Answers

An Air Handling Unit (AHU) consists of several parts that work together to condition and circulate air.

• Filter section: Removes dust and particles from the air.

• Heating coil: Warms the air before it is distributed.

• Cooling coil: Cools the air before it is distributed.

• Humidifier: Adds moisture to the air if needed.

• Fan: Circulates the air through the AHU.

• Dampers: Control the flow of air.

• Mixing chamber: Mixes outside and ret...read more

ACPH stands for Air Changes Per Hour.

• ACPH is a measurement used to determine the rate at which the air in a space is replaced with fresh air.

• It is commonly used in HVAC systems to ensure proper ventilation and air quality.

• ACPH is calculated by dividing the volume of air in a space by the flow rate of fresh air into that space.

• For example, if a room has a volume of 1000 cubic feet and fresh air is supplied at a rate of ...read more

The recommended ACPH for a kitchen depends on the size and type of kitchen.

• The recommended ACPH for a commercial kitchen is 15-20 ACPH (air changes per hour).

• The size and type of kitchen, as well as the type of cooking equipment used, can affect the recommended ACPH.

• The ACPH can be calculated by dividing the volume of the kitchen by the airflow rate.

• Proper ventilation and exhaust systems should be in place to maintain ...read more

VAV stands for Variable Air Volume.

• VAV is a type of HVAC system that varies the airflow to different zones based on their heating and cooling needs.

• It uses dampers to control the amount of air flowing into each zone.

• VAV systems are energy-efficient and can save money on heating and cooling costs.

• They are commonly used in commercial buildings and large residential buildings.

• VAV systems can be controlled by a building au

VAV stands for Variable Air Volume. It is an HVAC system that controls the airflow to different zones based on their heating and cooling needs.

• VAV uses a series of dampers to regulate the amount of air flowing into a space.

• It measures the temperature of the air in each zone and adjusts the airflow accordingly.

• VAV systems are energy-efficient as they only supply the amount of air required to maintain the desired tempera...read more

The thumb rule to calculate water consumption in a cooling tower is 3 GPM per every 100 tons of cooling.

• Water consumption in cooling tower is calculated based on the cooling load

• The thumb rule is 3 GPM per every 100 tons of cooling

• Factors like temperature, humidity, and air flow rate affect water consumption

• Water treatment and maintenance can also impact water consumption

Parameters considered while calculating heat load in a room

• Size of the room

• Number of occupants

• Type and number of electrical appliances

• Number and size of windows

• Insulation of walls and ceiling

• Orientation of the room

• Climate of the region

Directions affect the amount of heat transferred and the efficiency of the system.

• Heat transfer is affected by the direction of the flow of fluids or gases.

• The orientation of the surface being heated or cooled affects the amount of heat transferred.

• The direction of the sun's rays can affect the heat load on a building.

• The direction of wind flow affects the heat load on a building.

• Considering directions helps in designi