Heating, Ventilation and Air-conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a sub discipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. Refrigeration is sometimes added to the field's abbreviation as HVAC&R or HVACR, or ventilating is dropped as in HACR (such as the designation of HACR-rated circuit breakers).
HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, onboard vessels, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.
Ventilating or ventilation (the V in HVAC) is the process of exchanging or replacing air in any space to provide high indoor air quality which involves temperature control, oxygen replenishment, and removal of moisture, odors, smoke, heat, dust, airborne bacteria, carbon dioxide, and other gases. Ventilation removes unpleasant smells and excessive moisture, introduces outside air, keeps interior building air circulating, and prevents stagnation of the interior air.
Ventilation includes both the exchange of air to the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building may be divided into mechanical/forced and natural types.
The three central functions of heating, ventilation, and air conditioning are interrelated, especially with the need to provide thermal comfort and acceptable indoor air quality within reasonable installation, operation, and maintenance costs. HVAC systems can be used in both domestic and commercial environments. HVAC systems can provide ventilation, reduce air infiltration, and maintain pressure relationships between spaces. The means of air delivery and removal from spaces is known as room air distribution.
In modern buildings the design, installation, and control systems of these functions are integrated into one or more HVAC systems. For very small buildings, contractors normally estimate the capacity and type of system needed and then design the system, selecting the appropriate refrigerant and various components needed. For larger buildings, building service designers, mechanical engineers, or building services engineers analyze, design, and specify the HVAC systems. Specialty mechanical contractors then fabricate and commission the systems. Building permits and code-compliance inspections of the installations are normally required for all sizes of building.
Although HVAC is executed in individual buildings or other enclosed spaces (like NORAD's underground headquarters), the equipment involved is in some cases an extension of a larger district heating (DH) or district cooling (DC) network, or a combined DHC network. In such cases, the operating and maintenance aspects are simplified and metering becomes necessary to bill for the energy that is consumed, and in some cases energy that is returned to the larger system. For example, at a given time one building may be utilizing chilled water for air conditioning and the warm water it returns may be used in another building for heating, or for the overall heating-portion of the DHC network (likely with energy added to boost the temperature).
Basing HVAC on a larger network helps provide an economy of scale that is often not possible for individual buildings, for utilizing renewable energy sources such as solar heat, winter's cold, the cooling potential in some places of lakes or seawater for free cooling, and the enabling function of seasonal thermal energy storage.
What One Learns
Below are some of the areas one will study when one enrolls in HVAC training program:-
How You Learn
Once you have enrolled in HVAC education program at EXIN, one will begin to study many areas. These areas include theory and application of air conditioning and refrigeration, thermodynamic cycles, accessories, devices and refrigerants. One will also cover advanced topics related to commercial units that include installation, heat load calculations, low temperature systems and multiple system installs.
During HVAC classes at EXIN, one will discover the basics of electrical control work and learn skills for using ladder diagrams, test meters, wiring diagrams and thermostats. Our advanced teachings review pneumatic and electronic controls and how to service and maintain both.
On the heating side of things, one will learn the principles of heating technology and appliances, which includes forced-air fuel gas, electrical, oil, combustion processes and heat pumps. Both residential and commercial applications are covered, as well as codes, venting and piping practices, too.
Also included in heating and ventilation training is steam and hot water systems typically used in both residential and commercial installs. This training involves boilers, circulators, pipes, traps, heat exchanges and controls. The basics of fabrication and sheet metal as they apply to HVAC ductwork is also a part of your education.
Skills You Learn
Understanding How Different HVAC Systems Work
Understanding the functionality, technical specifications, and differences between various HVAC heating systems is definitely a key skill students learn in HVAC training. Here’s a look at some of the systems you will study, and their primary attributes:
1) Forced air furnace systems
The furnace blows heated air through ducts, which deliver the warmth to each room via air registers or grills.
2) Hydraulic boilers
Boilers work by heating water and circulating it throughout a building via warming baseboards, radiators, radiant tubing in floors and/or ceilings, etc. The cooled water returns to the boiler to be re-heated, and the process begins again.
3) Heat pumps
Heat pumps are capable of both heating a structure in the winter and cooling it in the summer. There are two different kinds of heat pumps: air-source (above ground) and ground-source (below ground). Air-source pumps are cheaper, easier to install, and therefore more common. During the summer, an air-source heat pump simply moves heat from the indoor space to outside. In the winter, it moves warm air into the house with the help of an electrical system. A forced air system circulates the warm air throughout the structure.
These are just three of the residential and light commercial HVAC systems students learn to understand, install, and service in HVAC training programs.
2. HVAC Piping & Venting Methods
Students in pre-apprenticeship HVAC programs will also learn how to thread and install gas piping systems, in both soft copper and black steel. They will explore the fundamentals of duct systems, which provide for the controlled flow of air throughout a building. Ducts can be made of fiberglass ductboard, insulated plastic, or sheet metal—so students can expect hands-on training with some or all of these materials.
Another key concept HVAC courses will cover is ventilation, which is a critical factor in controlling temperature and maintaining indoor air quality. Students will learn the differences between, and applications of, different types of ventilation methods, such as:
3. HVAC Safety Regulations, Protocols & Practices
One of the most important skills students learn in HVAC courses is safety requirements and procedures. Training should cover several areas of best practice, including:
Duration of the Course: 3 months
Interested candidates must have appeared/passed the CBSE/ISCE/ISC/Regional Board (or any other equivalent board) 10+2 examination in any discipline. Candidates who have recently appeared for the examination and are awaiting their results may also apply.
We, at EXIN follow the following evaluation procedures for admission to its various courses. Candidates have to undergo:
The admission procedure to various courses at EXIN follows the method of:
1. An admission test.
2. An all-inclusive interview.