Literary Review Team48

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HVLS Fans: Aisin Mfg. Illinois Page 1 of 13

HVLS FANSAISIN MFG. ILLINOIS

TEAM 48 LITERARY REVIEW


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Table of Contents

Executive Summary ...................................................................................................................... 3

I. HVLS FANS ............................................................................................................................... 4

Table 1: Comparison of HVLS Fans ..................................................................................................... 4 Concepts ................................................................................................................................................... 4 Benefits ..................................................................................................................................................... 5

II. HVAC SYSTEMS .................................................................................................................... 5 Chillers - Background ............................................................................................................................. 5

Chiller Controls ..................................................................................................................................... 6Advantages of Chillers .......................................................................................................................... 7

Current Setup .......................................................................................................................................... 7

III. THERMAL COMFORT ....................................................................................................... 8 Figure 1: Thermal Interaction of the Human Body with the Environment ...................................... 8

Figure 2: ASHRAE Summer and Winter Comfort Zones .................................................................. 9 Figure 3: Air Speed to Offset Temp above Warm-Temp Boundaries of Figure 2 ................ ............ 9 Figure 4: Air Velocities and Operative Temperatures at 50% RH Necessary for Comfort ofPersons in Summer Clothing at Various Levels of Activity ................. ................. .................. .......... 10 Figure 5: Draft Conditions Dissatisfying 15% of Population ....................... ................. .................. . 11 Figure 6: Percentage of People Dissatisfied as Function of Mean Air Velocity ........... .................. . 11

V. ELECTRICAL CODES ............................................................. Error! Bookmark not defined.

VI. References ............................................................................................................................. 13 HVLS FANS .......................................................................................................................................... 13

Table 1 ................................................................................................................................................ 13HVAC Systems ...................................................................................................................................... 13 Thermal Comfort .................................................................................................................................. 13


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Executive SummaryAisin Mfg. Illinois is a manufacturing company located in Marion, IL that produces automotive

components for manufacturers such as Toyota, GM, and Lexus. Over the last few years, Aisin

has begun to have difficulty maintaining the air temperature in the plant at a comfortable level

during hot summer days. To solve this problem, they have asked Team 48, a division of the

Saluki Engineering Company, to look into HVLS fans as a proposed supplement to the current

HVAC system. Team 48 has set out to bring Aisin three possible solutions with

recommendations as to the best choice for solving this problem. Currently, the thought is to

implement HVLS fans working in parallel with the existing chillers to attempt to better the

working conditions in the summer months. The effects of adding the fans for both summer and

winter months will be investigated, hoping for both a bettered working environment as well as

potential energy cost saving. Along with the fans, other methods of reaching the desired

environment will be investigated. These may include a new chiller system to work as an

assistant/backup to the current system being implemented with or without the HVLS fans.


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I. HVLS FANSHigh Volume Low Speed (HVLS) fans are a relatively new technology that is starting to gain

much momentum in the HVAC world. Since the technology is so new, there are only a few

major producers of these fans which include Macro Air , BigAssFans, and Rite-Hite . Table 1shows some specifications of fans comparable in maximum displacement and horsepower from

these companies.

Table 1: Comparison of H VL S F ans

Because Aisin has decided to test out a fan from Macro Air , this is where the project will start.

Macro Air has a wide range of fans from which to choose. They have a fan for any situation

and available in every electrical voltage, so it can be implemented into the existing electrical

system with minimal work. Currently, Aisin is using the MaxAir24 (see Table 1) as a

demonstration model on the floor.

Concepts

The basic concept of HVLS fans involves using special blades and oversized dimensions to

move large quantities of air. They look like greatly oversized ceiling fans and can measure up to

twenty-four feet in diameter. Ceiling fans have been around for many years, but these new

companies have incorporated much high-end technology derived from airplane wings into the

design. The fan blades use an air foil design with greater pitch on the blade to get air flowupwards of 300,000 cfm and produce around 100 lbf of thrust. The design is especially

impressive as this air movement is all done at a low velocity, allowing workers to remain

undisturbed by windy conditions. Instead the fans produce low speed columns of air that hit the

ground and spread out along the floor, reaching well beyond the footprint of the fan. The

construction of the fan is of aluminum and aluminum alloys in order to reduce weight (the Macro

Company MacroAir Big AssFansBig Ass

Fans Rite-Hite Rite-Hite Rite-Hite

Model Name MaxAir24 PowerfoilXPowerfoil

X Plus Revolution Revolution Revolution

Diameter (ft.) 24 24 24 24 20 16# of Blades 6 10 10 4 4 4Power of Motor (HP) 2.0 2.0 2.0 2.0 2.0 2.0

Max Displacement (CFM) 376,804 345,941 368,516 428,000 400,000 365,000Max Speed (RPM) 65 42 39 48 58 72Max Effective Area (ft 2) 20,000 20,000 30,000 22,000 20,000 20,000Fan Weight 236 439 446 300 292 284


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Air fan weighs in at only 236 lbs). When this is combined with the fact that only a 2 hp

electrical motor is used, it can be seen that the fan uses very little electricity.

Benefits

HVLS fans result in decreased energy costs in relation to heating and cooling in every facilitythat has been looked into. From research, the actual energy savings has varied based on the size

of the building, layouts, and individual comfort levels, but seems to range from a 10% to 30%

savings. Besides energy savings, there are also many other benefits of HVLS fans. When

installed in buildings, people report that the humidity levels have decreased significantly, the air

quality has improved due to better mixing of the air, and worker productivity has also improved.

In the summer months, these fans are best used at a high speed setting, pushing a lot of air down

from the ceiling. In the winter, most people want to reverse the fans to get the best effect.

However, this is actually counterproductive. The most effective way to use these fans during

cold months is to keep them blowing down but at a very slow speed. This gradually moves the

hot air down to the workers without creating any draft effect or wind chill, as discussed later.

II. HVAC SYSTEMSIn order to study the effects of adding HVLS fans to the environment, it is important to have a

solid understanding of HVAC (heating, ventilating, and air-conditioning) systems both of how

they work and what the current setup at Aisin is. If the addition of fans is insufficient to reachrequirements, it is possible that additional cooling will be required via a new chiller or some

other method of HVAC.

Chil ler s - Background

HVAC chillers are refrigeration systems that provide cooling for industrial and commercial

applications. Chillers consist of a compressor, condenser, thermal expansion valve, evaporator,

reservoir, and stabilization assembly. Chilled water systems operate like a normal air

conditioning unit except that they use water instead of refrigerant in the condenser unit. A water-cooled air chiller works by pumping refrigerant through coils that cool the water, filling the

condenser coils with the circulating cool water. Refrigerant is compressed, creating a high

pressure gas. The condenser uses cool water to condense the compressed gas turning it into a

warm liquid. The warm liquid goes through the thermal expansion valve releasing refrigerant


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into the evaporator while converting the warm liquid into a cool, dry gas. A hot gas bypass is

generally used to warm up the evaporator to stabilize the temperature of the chilled water. The

water is then pumped from the reservoir to the compressor to start the cycle over. The

temperature of the water pumped through the coils is determined by the set point of the chiller.

The temperature change through the chiller is typically around 10 degrees. The normal

temperature of the water leaving the chiller is generally around 45 degrees, so the water returning

to the chiller is generally around 55 degrees.

Chiller Controls

There are three different sizes for the power sources of the controls for the chillers. These power

sources are given by three numbers separated by forward slashes. The first number indicates the

voltage, the second number refers to the frequency, and the third refers to the phase of the

source. The power sources for the controls come in the following sizes: 208-230/60/3, 380/50/3,

and 460/60/3. HVAC chillers can have a local or a remote control panel with temperature and

pressure indicators. Some control units also have microprocessor controls, emergency alarms,

and an integral pump. HVAC chillers can also be used to cool plastics, printing equipment, laser

cutting machines, and magnetic resonance imaging equipment. The microcomputer control panel

includes all of the controls necessary for the safe and reliable operation of the chiller. There are

many types of controls available for chillers. Fastforward adaptive control is a predictive control

strategy used to compensate for load changes. Soft loading is a control used to accommodateload changes or temperature set point by gradually applying these changes, preventing

unnecessary cycling by the chiller. Multi-objective limit arbitration keeps the chiller focused on

its main priority (leaving evaporator temperature) until it can no longer obtain its ideal

temperature, then it switches to the chillers second main priority. The adaptive frequency drive

control mathematically figures the best position for the inlet guide which allows the system to

run longer and for better efficiency. The variable primary flow control reduces the energy

consumed by pumps. Variable flow compensation improves the chillers ability to accommodate

variable flow. With this information, it will be possible to look into the possibility of coupling

the systems (HVLS fans and the chillers) and find the best method for controlling the systems.


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Advantages of Chillers

Air chillers are convenient as they permit the components of the system to be sold separately,

allowing the engineer to place different parts of the system strategically to accommodate space

specifications. Chilled water refrigeration systems are preferred because of their contained use

of refrigerant. The refrigerant in these units is centralized minimizing the risk for leaks or

making it easier to contain if one does arise.

Cur rent Setup

HVAC systems are used to make for a more comfortable indoor environment and are employed

by many different sizes of indoor environments ranging from an automobile to a 290,000 square

foot automobile component manufacturing plant such as Aisin Mfg. There are also different

types of HVAC systems. Trane offers a Direct-Expansion Unitary System, where an evaporator

is in direct contact with the air stream, and a Chilled Water Applied System, which is the system

currently in use at Aisin. A chilled-water applied system uses chilled water to transport heat

energy between the airside, chillers and the outdoors (Trane). Trane is not the only HVAC

manufacturer in the market; during a period of expansion, Aisin doubled the size of its

manufacturing facility and added an Aaon HVAC system to the addition which is similar to the

existing Trane setup. The chillers at Aisin have a capacity of 400 tons, and are set to cool the

water to 42 degrees Fahrenheit. They are connected to seventeen roof top units that pump out

the cooled air. Twelve of the roof top units (six on the original side and six on the addition) areresponsible for providing conditioned air to the main manufacturing section of the building that

is being studied. With temperatures topping out around eighty-three to eighty-five degrees inside

the manufacturing section, these chillers are running at maximum capacity 24 hours a day.

During the summer months, the temperature level in the plant often reaches unacceptable levels,

and since the chillers are running at full capacity during this time, there is no way for the current

system to keep the environment at a comfortable temperature.

In such situations, many companies have made the decision to simply add another chiller to the

equation. However, chillers that are the size of those at Aisin are quite expensive, and there are

other ways to deal with these uncomfortable temperatures. In looking for a solution to the

problem at Aisin, the effect of airflow through the plant to make for a more comfortable working

environment will be studied. One way to improve the airflow is the addition of the HVLS fans

in order to circulate the cool from the AC units to all of the employees on the plant floor.


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III. THERMAL COMFORTThermal comfort, as stated by ASHRAE Standard 55, is that condition of mind that expresses

satisfaction with the thermal environment (ASHRAE). In itself, thermal comfort is not

quantifiable but is based on ones physical, psychological, physiological, as well as other

processes. However, it is possible from an engineering standpoint to procure quantitative

stipulations for an environment that will provide for thermal comfort for an estimated percentage

of satisfied population. These standards are based on combined calculations of a heat transfer

energy balance of the human body in varying conditions as well as results of surveys taken of

people in these environments. The environmental factors affecting a persons thermal balance

and therefore his or her thermal comfort i nclude the surrounding airs dry bulb temperature,

humidity, relative velocity, and radiation (McQuiston). Besides these, personal variables

including the amount of activity and clothing of a person also affect his or her thermal comfort.

While some aspects of thermal comfort from the biological standpoint are beyond the scope of

this review, providing a comfortable work environment is essential for employee contentment.

Estimating thermal comfort can be simplified by doing an energy balance on the body, as done

by ASHRAE (see Figure 1), taking into consideration the majority of methods of heat transfer to

and from the body.

F igur e 1: Thermal I nteraction of the H uman Body with the Environment

The most applicable portion of thermal comfort for this project deals with the effect of wind

speed and humidity on thermal comfort (in relation to temperatures), both of which could

potentially be affected by the installation of HVLS fans and/or an additional HVAC unit.


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Although based off of a nearly sedentary level of activity, Figure 2 (ASHRAE) gives an estimate

of acceptable levels of operative temperature and humidity for environments of little to no air

movement for people wearing clothing appropriate for the season (1.0/0.5 clo winter/summer).

F igur e 2: A SH RAE Summer and Winter Comfor t Zones

With the addition of the HVLS fans, the hope is that the HVAC units will be able to run at a

lower load and that a higher temperature will be acceptable with the increased air movement.

This would allow for potential energy saving. Figure 3 displays the amount of air speed required

to offset temperatures above ideal operative temperature (ASHRAE). Similarly, Figure 4

(ASHRAE) shows necessary air velocities for operative temperatures at 50% relative humidity to

maintain comfort for different levels of activity measured in mets.

F igure 3: Ai r Speed to Off set Temp above Warm -Temp Boundar ies of F igur e 2


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F igur e 4: Air Velociti es and Operative Temperatur es at 50% RH N ecessary forComfort of Persons in Summer Clothing at Var ious L evels of Activi ty

It should also be mentioned that fans potentially could reduce dissatisfaction due to radiant

temperature asymmetry and vertical air temperature difference, as a significant amount of mixing

and more even conditions would occur throughout the plant, discussed earlier.

With an increase in air speed, it is possible to cause discomfort due to drafts, especially during

winter months. Active persons are much less sensitive to these discomforts (McQuiston) , and it

can be assumed that the majority of workers on the floor that would be affected by HVLS fans

will be somewhat active. However, in the winter months for workers doing near sedimentary

work, draft could potentially become an issue. For this reason, it is important to examine effects

of air movement on this subject. As stated earlier, in the winter HVLS fan manufacturers

recommend running the fans at lower speeds. This will cause warm air near the ceiling to be

slowly pushed downward. Figure 6 (ASHRAE) shows the effects of wind speeds and turbulences

causing 15% of the population to be dissatisfied. It would be wise to keep this concept in mind in

determining operating conditions of HVLS fans or the HVAC system as a whole. Along these

same lines, Figure 7 shows the percentage of people dissatisfies for different temperatures as air

velocities increase (ASHRAE).


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these requirements will allow modeling to be done in such a manner as to provide a comfortable

work environment while potentially saving in heating and cooling costs.

While this information is for standard acceptable conditions, it should be noted that Aisin has

their own requirements. The plant area where the study will be done is required to be in the range

of 68 to 82 degrees. While a specific humidity range is not required, a comfortable working

environment is necessary for team members working on the floor.


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VI. References

H VL S F ANS

DeGaspari. "A fan for all seasons." Mechanical Engineering 121.12 (1999): 58. MasterFILE

Premier . EBSCO. Web. 11 Oct. 2010."HVAC manufacturer finds a cool solution with HVLS fans." Plant Engineering 63.9 (2009):37-39. Academic Search Premier . EBSCO. Web. 30 Sept. 2010.

"HVLS Fan." Material Handling Management 65.7 (2010): 34. Business Source Complete .EBSCO. Web. 30 Sept. 2010.

Macro air . (2010). Retrieved from www.macro-air.com

Oleson, Rick. "The top 10 myths about HVLS fans." Plant Engineering 62.7 (2008): 40. Academic Search Premier . EBSCO. Web. 30 Sept. 2010.

Table 1"Installation and Warranty." MacroAir Technologies, Inc., 2010. Web. 4 Oct. 2010..

"Literature - Rite Hite - Revolution HV/LS Fans." Rite Hite - Revolution HVLS Fans. Rite HiteHVLS Fans, 2010. Web. 4 Oct. 2010. .

"Technical Downloads." Big Ass Fan Co. Delta T Corp., 2010. Web. 4 Oct. 2010..

H VA C Systems

Chilled Water Applied Systems - HVAC Systems . Trane, 2010. Web. 4 Oct. 2010.

Water Chiller System. Web. 5 Oct. 2010.

HVAC Chillers. Global Spec, 2010. Web. 5 Oct. 2010.

Thermal Comfort

2009 ASHRAE Handbook - Fundamentals (SI Edition) . American Society of Heating,Refrigerating and Air-Conditioning Engineers, Inc, 2009.

McQuiston, Faye C, Jerald D Parker and Jeffrey D Spitler. Heating, Ventilating, and AirConditioning Analysis and Design. 6th Edition. Hoboken: John Wiley & Sons, 2005.

Title Page Image Retrieved from < http://www.macro-air.com/158 >
http://www.trane.com/COMMERCIAL/HvacSystems/1_1_ChilledWater.aspx?i=863http://www.air-conditioning-and-refrigeration-guide.com/water-chiller-system.htmlhttp://www.globalspec.com/LearnMore/Building_Construction/HVAC/Cooling/HVAC_Chillershttp://www.macro-air.com/158http://www.macro-air.com/158http://www.globalspec.com/LearnMore/Building_Construction/HVAC/Cooling/HVAC_Chillershttp://www.air-conditioning-and-refrigeration-guide.com/water-chiller-system.htmlhttp://www.trane.com/COMMERCIAL/HvacSystems/1_1_ChilledWater.aspx?i=863

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