The Parts Of A Hvac

HVACs have become part and parcel of our daily lives. A HVAC is on round-the-year whether summer or winter to condition the air according to the need of the season. A HVAC stands for heating, ventilation, and air conditioning. The parts of an HVAC can be broadly divided into two categories – the Air conditioner (A/c) and the Furnace. In the cold chilly winter days the furnace kick starts to provide you warm air. In the hot, sweltering, and clammy days of summer the A/c is on to cool your rooms and to maintain an optimum level of humidity. Let’s take a look at the parts of an HVAC-

The Furnace

The furnace of a HVAC is of conspicuous size that will occupy quite a bit of space in the room. It is often kept in the attic, basement, or in a closet. The furnace can run on gas or oil. When you power it on, the thermostat sends a signal to the furnace to generate heat. A valve opens up sending the fuel to the burner. It is then ignited which generates heat. The heat is transferred to the room air through a heat exchanger. An electric furnace generates heat by powering an electric coil.

The Heat Exchanger

This is a mandatory part of every furnace. The cold room air is sucked into the heat exchanger. The cold air can come from to ways- from outside, or from the room. The duct that brings the cold room air to the exchanger is called a cold air return chase. The heat exchanger transfers the heat generated by the furnace to this cold air. The air is quickly heated and blown out through the ducts that take it from room to room.

The Evaporator Coil

The evaporator coil is an important part of a HVAC. It is through an evaporator coil that cold refrigerant flows. The hot room air after taken in through the ducts for cooling is first passed through a filter and then blown over the evaporator coil. The refrigerant in the coil absorbs the heat in the room air and makes it cool. The evaporator coils are attached to a different part of the furnace. You won’t see them within the furnace housing. They are usually, present inside a metal enclosure that is affixed to the side or the top of the furnace. The cold air from the evaporator coil is picked up by the furnace blower and sent along the ducts.

The Condensing Unit

The condensing unit is present outside the house. It is a separate unit from that of a furnace. The refrigerant after having absorbed the heat in the room air at the evaporator coil travels to the condenser unit via a copper tube. Here it first enters the compressor. The compressor pressurises the refrigerant, turning it into a hot, high-pressure gas. The gas them leaves for the condenser coil from the compressor. In the condenser, the refrigerant is condensed to release the heat that it absorbed from your house to the outside surrounding. As it is cooled the refrigerant changes from a hot gas to a cool liquid. From here it reaches the evaporator coil through the expansion valve for another cycle of cooling.

The Refrigerant Lines

These are thin tubes present in the HVAC. These are conduits made of aluminium or copper. These carry refrigerant from the condense unit to the evaporator coils and vice versa. These are quite durable and designed so to survive and function in extreme temperatures.

The Thermostat

A thermostat is a very important component of a HVAC unit. It is present within the building in a position where it can be accessed by users. You set the temperature that you need for your room through the thermostat. When you set a temperature at the thermostat, it is able to read you demand and therefore direct the HVAC to produce the required cooling and heating. Thermostats can also sample room air and therefore work automatically to generate optimum hot or cold temperature to make your room comfortable. If the air is tool cold, the furnace will be activated. If it is too hot, the AC will start running. As soon as the required temperature is reached the device cycles off. Thereafter, when the temperature goes lower or higher than required, the HVAC cycles on once again.

The Ducts and vents

Ducts are built during the construction of the building. There are network of pipes that carry hot or cold air from the unit to different rooms. They have blowers to propel the air forward. Each room has a rectangular opening. This is made to disperse the air that pours from the duct into the rooms below. They are often made in ceilings or walls. Their edges align with the opening of the ducts. They are made of rectangular frame which has a series of thin metal slats within. These slats are pointed downwards to make the air flow downward.


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