Hvac Basics

 🔥Heat🔥

It is a form of energy⚡ it transfer or flow from high temperature🌡️ to low temperature🌡️ body

Units of 🔥heat🔥

Joules calories B. T. U British 🇬🇧thermal unit

B. T. U is defined as amount of 🔥heat 🔥required to raise the temperature🌡️ of one pound of water 💦by 1°f

Calorie is defined as amount of🔥 heat 🔥required to raise the temperature🌡️ of one gram of water💦 by 1°c

Types of 🔥heat 🔥

Latent heat 🔥

Sensible 🔥heat

Latent heat🔥 change the phase of the object

Where as

Sensible heat 🔥change the temperature🌡️ of the object

Modes of heat 🔥transfer

Conduction

Convection

Radiation

Conduction takes place due to molecular vibrations 

In solids

Where as

Convection takes place due to molecular movement

In fluids

And

Radiation takes place without any molecule

Means no medium

Heat 🔥transfer in the form of EM 🌊waves🌊 means electromagnetic waves 🌊without affecting any medium 

For example

☀️Sun☀️ rays direct coming to earth 🌎without any medium means direct contact to earth 🌎in the form of rays this is the best example of Radiation heat 🔥transfer

TR means Ton of refrigeration

Ton of refrigeration is defined as amount of heat absorbed by one ton of ice 🧊which is at 0°c to melt completely within, 24hours in closed room is known as Ton of refrigeration

Or

Vice versa

The cooling effect produced by one ton of ice 🧊at 0°c by melting completely within 24 hours in a closed room at normal atmospheric pressure

One TR is equal to

12000 BTU/hr

3024 k. Cal/hr

3.517 kw

Ac is sold or buy in terms of tonn

Hence capacity of AC is measured in TR