This readily accessible App introductory resource was developed for anyone who has interest in or works with HVAC controls and equipment. Designed for electrical and HVAC apprentices learning about the subject in school you will find the descriptive text and original diagrams easy to navigate through while the question bank will help students review the subject matter covered in each section.

Heating ventilation and air conditioning (HVAC)[1] is the use of various technologies to control the temperature humidity and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline 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 "ventilation" is dropped as in HACR (as in 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; vehicles such as cars trains airplanes ships and submarines; 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. Methods for ventilating a building are divided into mechanical/forced and natural types.[2]



Abstract
HVAC systems are milestones of building mechanical systems that provide thermal comfort for occupants accompanied with indoor air quality. HVAC systems can be classified into central and local systems according to multiple zones location and distribution. Primary HVAC equipment includes heating equipment ventilation equipment and cooling or air-conditioning equipment. Central HVAC systems locate away from buildings in a central equipment room and deliver the conditioned air by a delivery ductwork system. Central HVAC systems contain all-air air-water all-water systems. Two systems should be considered as central such as heating and cooling panels and water-source heat pumps. Local HVAC systems can be located inside a conditioned zone or adjacent to it and no requirement for ductwork. Local systems include local heating local air-conditioning local ventilation and split systems.

App HVAC Include :

★ Lowes ac installation
★ velocity air conditioning
★ HVAC heating and air
★ HVAC maintenance service
★ emergency HVAC service
★ ac and heating repair
★ heating and air conditioning service
★ home ac repair
★ commercial air conditioning repair
★ best ac repair
★ efficiency mechanical heating & cooling
★ heating and cooling
★ Mechanical Cooling – General Applications
★ Hydronic Cooling Systems
★ Phase Changes
★ The DX Cooling Cycle
★ Mechanical Cooling – Principles
★ Gas Laws
★ Direct Expansion Air Conditioning Systems
★Thermostats – General
★ Baseboard Heat
★ Unit Heaters
★ In-Floor Heating
★ Gas Heat – Control
★ Thermocouples
★ Line Voltage Thermostats
★ Electric Heat – General
★ Central Electric Heat
★ Portable Heaters
★Pilot Lights