Components of an HVAC System - Case Study Example

Introduction HVAC (heating, ventilation, and air conditioning) is the skill of indoor and automotive environmental comfort. It uses the principles of thermodynamics, fluid mechanics, and heat transfer. It’s used in many sectors from design of small scale to large scale industries; marine environments where safe and healthy living conditions are regulated with respect to temperature and humidity form the atmosphere. HVAC is important in the design of medium to large industrial and office buildings such as skyscrapers and in marine environments such as aquariums, where safe and healthy building conditions are regulated using fresh air from the outdoors (Kavanaugh, p12). Components of a HVAC system Furnace; is the control center for a HVAC system, and is typically installed in a dedicated closet space, basement or attic in a building. Heat Exchanger found within the main furnace unit. When the system is turned on, heat air drawn into the air exchanger from outside of the building through a cold air return chase, which draws cool air from the interior of the building as it’s replaced by warmed air. Evaporator Coil; supplies cooled air for the furnace blower to distribute through the ducts or airways and is made of metal tubes surrounded by thin aluminum fins, which cool the air similar to a radiator in an automobile. Refrigerant Lines; made of copper or aluminum tubing lines that carry liquefied refrigerant from the condensing unit to the evaporator coil and then recycle the vaporized refrigerant back. Condensing Unit; located outside of the building and has a compressor that condenses refrigerant gas, cooled by heat exchange with the outside air, to a fluid, then pumps the fluid through a metal line to the evaporator coil in the furnace unit. As it passes through the evaporator coil, tiny spray nozzles spray the cooling fluid into a chamber, which lowers the pressure and the fluid evaporates back into a gas. In a building, they are supplement as they provide thermal comfort during cold weather, and fresh air within the reasonable distance from where they have been installed. They also minimize air infiltration and ensure pressure in different parts of a building is in equilibrium. They also ensure room air distribution. Some of it components include a thermostat, furnace, heat exchanger, condensing unit, refrigerant lines, and evaporating coil. In a building they serve various purposes which are usually perceived to be of help than harm; a thermostat is a temperature sensitive switch, used to control the HVAC system. When temperature lowers beyond room temperature switch the system to heat the room in therefore rising to the require room temperature. It also switches off the system if the optimum is achieved to prevent further heating. In this it enables the HVAC system to regulate the temperature of the building. High temperatures n a building causes a lot of discomfort while low temperature can lead to breathing difficulties. The HVAC systems also play a major role of air conditioning. It filters the allowing fresh and clean air in a building. This filtered air is suitable for inhaling. It prevents inhaling air which is contaminated thereby minimizing ones chances of developing breathing problems Thermal comfort refers to the state of mind in humans that convey satisfaction with the environment at which the person is exposed to. In a building human thermal comfort is always boosted by HVAC systems. Maintaining this standard of thermal comfort for occupants of buildings and other things in the building is one of the paramount goals of HVAC (heating, ventilation, and air conditioning) design engineers. It is always affected by form of heat transfer that includes conduction, convection, radiation, and evaporative heat loss. Complaints about human thermal comfort Thermal comfort complaints within work places are one of the leading causes of workforce output loss within offices. Normally, mechanical systems are relied on to provide ample indoor environments. In many cases, these systems cannot provide suitable work environments due to improper radiant temperature conditions found in outdoor zones of building interiors several ways using infrared technology to support building and workplace managers in reducing thermal comfort complaints and improve workforce yield (Lin & Han, p43). Discovery solutions are easily and effectively carried out with the assistance of infrared radiometers. Some of the complains includes, too hot or too cold surroundings, experiencing of same degree of temperature for a long period of time (climate monotony) and high power demands which is always accompanied with high costs. Energy consumption and HVAC Effective ways can be put in place to check the thermal comfort huge energy consumption. They include; 73% Updating or replacement HVAC components or system, 52% Verification of the building automation system (BAS) is working as designed, 27% Installation of more efficient light fixtures that reflect less heat, 24% Modification of ductwork. 24% Installation of new window shades, 24% Added window film to improve thermal properties, 18% Retro-commissioned the building, 15% Provision more local control to occupants, 10% Green initiatives such as green roofs, heat recovery and solar water heating (Westphalen et al, p36) Ways of modification for low energy consumption in buildings and homes To reduce the amount of energy used in the buildings and homes, building science may be applied. This enhances the use of equipment like blower doors, duct blaster, thermo graphic camera and combustion analyzer. These help in maintaining the amount of energy in use. The use of the double pale window; this reduces the energy consumption by up to fifteen per cent.irt works on the basis of the fact that it has a layer which serves as an insulator which controls the heating and cooling of a house. Homes have also adopted the use of energy saving devices like energy saving heaters and coolers, bulbs and fluorescent tubes for lighting instead of the more energy hungry appliances. In many places, energy consumption has been reduced by the means landscaping processes. This has included the planting of trees create an ample atmosphere for the circulation of energy. The trees have provided shade which has reduced the cooling cost, served as wind breaker thereby reducing energy loss through wind. In some homes, window insulator method has been used to help reduce the amount of heat penetrating into the buildings from the sun. By preventing this heat, the amount of energy required to cool the building is reduced. It had been applied in building with glass windows which have direct link to the sun (Westphalen et al, p67). It uses the solar control film which absorbs the ultra-violet component of the solar energy and absorbs the infra-red. Some buildings and homes have been built using materials which favor the energy circulation processes. Most buildings are made of concrete which is not a conductor of heat energy; this has reduced the loss of the internal energy. During the cold conditions this has reduced the energy required to heat the room. Some buildings, more often those meant for large numbers of people have adopted the building of tall or high ceilings this increased the air conditioning process in the building. The above modifications have made the HVAC systems which were previously used have their function restricted to extreme conditions which cannot be controlled by the new modifications. The use of HVAC systems therefore have majorly used some areas where only these modifications cannot work or where modifications cannot be done. Impact of improper use of HVAC on the global environment The use heaters and coolers to regulate the temperatures of the buildings have resulted in the pollution of atmosphere. For example, use of kerosene in the appliances for heating or warming has led to the emission of carbon monoxide which is hazardous to the atmosphere as it causes global warming. The smoke from stove and other appliances ought to have been properly channeled. Some of refrigerant may be wearing out and if these not repaired or maintained, leakage of their fuel may occur. These leaked fuels contain variety of components including gases sulfide gases, chloride gases and carbon gases. These gases corrode the ozone layer reducing its preventive layer. This has lead to the excess solar heat reaching the earth. The excess heat reaching the earth has made the temperature to rise to very high levels. Some of material used to make the heaters and refrigerant react with oxygen from the atmosphere. These reduce the amount of oxygen available for use in the combustion reaction in the environment. This reduction in the amount of oxygen has left more of the chlorofluorocarbon gases which penetrate into the sky. Usage of renewable energy systems to supplement or replace the HVAC The use of these renewable energy systems is healthier to the environment as very little if not no emission to the surrounding. They are therefore the recommended systems to use in maintaining the conditions of the rooms and buildings. There had been the use of solar energy (ultraviolet radiations) for the heating. The heat generated by the sun is adequate and inexhaustible in the regions where the sun shines throughout. This energy from the sun can be tapped and be used to run machines which rely on electricity for power. These devices therefore can still perfume their function with the use of solar energy. Wind power energy can also be used to run coolants and heaters. Wind power is a renewable source of energy and can be easily harnessed to run coolants like fans and heaters. It has no impact on the environment and is easily accessed. If used it can replace the electrically run machines and this will reduce the pollution caused to the environment during power generation. The use systems run by light energy; photovoltaic power machine can be implemented to replace the existing heat, ventilation and air conditioning system. This can be devised to provide a cooling effect in the building or at home cheaply by harnessing the light then converting it to energy then using the produced energy to create required condition. Works Cited Kavanaugh, Stephen P.. HVAC simplified. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers, 2006. Print. Lin, C. H., and T. Han. Effects of HVAC design parameters on passenger thermal comfort. Warrendale, Pa.: Society of Automotive Engineers, 1992. Print. Westphalen, Detlef, Scott Koszalinski, and Inc Little. Energy consumption characteristics of commercial building HVAC systems. Cambridge, MA: Arthur D. Little, Inc., 1999. Print. Read More