HISTORY
HVAC units are used all over the United States and part of the world as well. With a humid and hot climate like the city of Houston, they are essential for good work productivity and comfort. With temperatures able to reach temperatures of over 90 °F, sometimes HVAC units become necessary to beat life threatning temperatures. The first ever modern air-conditioning system was designed byAlfred Wolff and installed at the New York Stock Exchange. The system weighted 300 tons and worked using cooling from waste-steam-operated refrigeration systems. The first air conditioning in an office building was installed that same year at Kansas City Missouri. Houston did not get an air condtioning until 1922. It was installed at the Rice Hotel cafeteria.The first private home was air-conditioned in 1932 [1]. The book "Air Conditioning America" talks about a survey done in 1957, where 90% of American firms said cooled air was the biggest boost to their productivity. Since then, different energy standards have been passed by goverment that have shaped the evolution of how we use HVAC units.
HVAC SYSTEMS
It stands for heating, ventilation, and air conditioning unit. It is a system that combines the three functions into one system. Most homes and buildings today have them, and if they don't they've chosen to be unproductive. They allow the users to regulate the temperature inside of the building without being limited to just one room.
AIR CONDITIONING
![Picture](/uploads/9/5/2/6/95266746/1481070339.png?250)
AC units are systems used to cool a whole room, house, or building. These systems use chemicals to transfer heat from the air inside of the building to the outside. The system has 3 main parts. These are the compressor, evaporator, and condenser. In a house, the evaporator is usually inside while the the compressor and condenser and on the outside [2]. Figure 1 shows exactly how and AC unit in a house works. Image taken from the U.S. department of Energy. When buying a new air conditioner it is important that it operates quietly. Having a fan only switch is also important because it allows you to save energy consumption at nighttime [3].
RTU
An RTU is an HVAC unit that is placed on the rooftop of large buildings. Most large buildings today have these types of HVACs. They have large capacities for large buildings. These units can provide single or multi-zone cooling and ventilation for the area below.
VRF
![Picture](/uploads/9/5/2/6/95266746/daigram.png?263)
It stands for Variable Refrigerant Flow. Like typical HVAC units, they are air-cooled and refrigerant based. The difference between regular HVACs and VRFs is that VRFs have multiple units pumping out air instead of just one big one. They have the ability to control how much refrigerant flows to each air handler. They are more energy efficient because they run less frequently than other HVACs. Their design allows them to control the amount of energy used to cool a specific room. Their upfront cost is more than older HVACs, but after a certain time, lower energy costs will offset it. When picking a model, different numbers need to be taken into account [5].
SEER
![Picture](/uploads/9/5/2/6/95266746/seer-vs-eer-seer-rating-tag.jpg?206)
Air conditioners are rated using SEER. It stands for seasonal energy efficiency ratio. This number is the amount of energy needed to provide a specific cooling output. SEER is the cooling output divided by the electrical input during that time period. HVACs have a lifespan of 15 to 20 years. A higher SEER means your unit will use less energy to cool the area, which means it is more efficient. New standards went into effect in the last couple of years which will raise the minimum SEER a system can have. This will allow for higher efficiency, lower energy costs, and less use of fossil fuels [3].
IEER
It stands for integrated energy efficiency ratio. This number is able to reflect an HVACs unit in a more real-world setting. It can capture efficiency ratings when the system is working at 25-100% efficiency. The new proposed set standards, set by the Department of Energy, would place the minimum IEER at 12.3 to 14.8 depending on size and equipment. The best systems today can achieve IEERs of 21 [8].
Click the button to the right to go to the next page, Refrigerants.
|
Sources:
[1] "Air-conditioning," [online], December 5th 2016, Texas State Historical Association, website:https://tshaonline.org/handbook/online/articles/cmarp.
[2] "How does an air-conditioner work," [online], December 5th 2016, Energy Quest, website:http://www.energyquest.ca.gov/how_it_works/air_conditioner.html.
[3] "Central Air-conditioning," [online], December 5th 2016, U.S. Department of Energy, website:http://energy.gov/energysaver/central-air-conditioning.
[4] "Energy Saver 101 Infographic: Home Cooling," [online], December 4th 2016, U.S. Department of Energy, website:http://www.energy.gov/articles/energy-saver-101-infographic-home-cooling.
[5] "7 reasons to choose VRF" [online], December 5th, 2016, Arista, website:http://aristair.com/blog/7-reasons-to-choose-vrf-hvac-technology-for-your-new-air-conditioning-2/.
[6] " MEP Company Defines Variable Refrigerant Flow," [online], December 5th 2016. KMB Design Group, website:http://www.kmbdg.com/articles/mep-engineering-company-variable-refrigerant-flow/.
[7] "Understand what SEER is," [online], December 5th 2016, All Systems Mechanical, website:http://asm-air.com/airconditioning/seer-vs-eer-what-is-seer-what-is-eer/.
[8] "New Air Conditioner Standards Would Rank as Biggest Energy Saver in U.S. DOE History," [online], December 5th 2016, American Council for an Energy-Efficient Economy, website:http://aceee.org/press/2014/09/new-air-conditioner-standards-would-
[1] "Air-conditioning," [online], December 5th 2016, Texas State Historical Association, website:https://tshaonline.org/handbook/online/articles/cmarp.
[2] "How does an air-conditioner work," [online], December 5th 2016, Energy Quest, website:http://www.energyquest.ca.gov/how_it_works/air_conditioner.html.
[3] "Central Air-conditioning," [online], December 5th 2016, U.S. Department of Energy, website:http://energy.gov/energysaver/central-air-conditioning.
[4] "Energy Saver 101 Infographic: Home Cooling," [online], December 4th 2016, U.S. Department of Energy, website:http://www.energy.gov/articles/energy-saver-101-infographic-home-cooling.
[5] "7 reasons to choose VRF" [online], December 5th, 2016, Arista, website:http://aristair.com/blog/7-reasons-to-choose-vrf-hvac-technology-for-your-new-air-conditioning-2/.
[6] " MEP Company Defines Variable Refrigerant Flow," [online], December 5th 2016. KMB Design Group, website:http://www.kmbdg.com/articles/mep-engineering-company-variable-refrigerant-flow/.
[7] "Understand what SEER is," [online], December 5th 2016, All Systems Mechanical, website:http://asm-air.com/airconditioning/seer-vs-eer-what-is-seer-what-is-eer/.
[8] "New Air Conditioner Standards Would Rank as Biggest Energy Saver in U.S. DOE History," [online], December 5th 2016, American Council for an Energy-Efficient Economy, website:http://aceee.org/press/2014/09/new-air-conditioner-standards-would-