its property. “LEED” and related logo is a trademark owned by the U.S. Green Building Council and is used by permission. The LEED® Rating System was authored
by and is the property of the USGBC. Any portion of the Rating System appearing in this course is by permission of the USGBC. Questions or concerns about the
content of this course should be directed to the program instructor.
Purpose & Learning Objectives
Course Purpose:
Provide an overview of High Volume, Low Speed (HVLS) fans and discuss the environmental benefits of
air movement, thermal comfort, supplementing traditional HVAC systems with HVLS fans, innovation in fan
technology, and the standards that govern fan performance.
Learning Objectives:
• Describe the environmental benefits achieved by specifying HVLS fans;
• Define thermal comfort and list the factors that affect it;
• Summarize how pairing HVLS fans with HVAC systems improves energy efficiency;
• Discuss design factors that impact the amount of energy used by HVLS fans
• Outline the standards that govern fan performance; and
• List the LEED ® v4 credit categories HVLS fans can contribute points.
What is HVLS?
HVLS fans are large ceiling fans that move a High Volume
of air at a Low Speed.
High Volume:
• Longer blades create a wider column of air
• Wider columns of air travel farther
• Deep horizontal floor jets impact all adjacent areas
Low Speed:
• Gentle air movement rather than disruptive wind
• Nearly silent operation
• Low velocity reduces the power required to drive the fan
➤ Complete air circulation throughout large, high ceiling
areas for a minimal cost.
How it Works
Summer Usage:
Large air column
delivers cooling
breeze across the
entire body.
Winter Usage:
Slow moving air
column carries warm
air from the ceiling
down to floor level.
HVLS or Tradit ional?
Traditional Fans HVLS Fans
Speed High Velocity ~20 mph
Low Velocity ~8 mph
Efficiency 4ft: 28 CFM/Watt 24ft: 210 CFM/Watt
Coverage Concentrated Thorough
Experience Noise, dust, distraction
Quiet, non-disruptive
Volume Output 4ft: 20,000 CFM 24ft: 346,000 CFM
Lifecycle Short Long
HVLS Fan Industry
Market Distribution
Warehousing & Distribution 37%
HVAC (climate controlled) 16%
Automotive 13%
Agriculture 11%
Aviation 7%
Manufacturing 6%
Education 5%
Commercial 5%
Industry Applications
HVLS fans were invented to solve a problem:
cows produce less milk when they are hot.
Agriculture
Industry Applications
Automotive
Industry Applications
Stadium Fitness
Industry Applications
Restaurant
Industry Applications
Airport
Brewery
Benefits of Using HVLS Fans
Thermal Equalization
Problem: Air Layers develop because warm air expands, making it lighter than cooler air. • Heated air is 5-7% lighter • Temperature increases about 0.5°F each foot • HVAC systems are often oversized to
overcome stratification
Solution: De-stratification: HVLS fans break up heat layers, equalizing the temperature. • Eliminate “cold spots”/“dead spots”
Thermal Equalization
Winter Usage
• Bring warm air down from the ceiling
• Reduce heat loss through the roof
• Eliminate cold spots
• Save 25% on heating costs
Cooling Effect
Summer Usage
• Cooling effect: breeze accelerates
evaporation of sweat so people feel 8°F
cooler
• Increase thermostat settings
– Save 30% on cooling costs
• (3-5% energy savings per degree
when the set point is increased)
Cooling Effect
NASA Study showing the impact effective temperature has on workers’ output and accuracy:
*Effective temperature is the combined effect of temperature, humidity, and air motion on the body.
Source: Bottomley, T.A., E.M. Roth. “Compendium of Human Responses to the Aerospace Environment.” 6. Thermal Environment. NASA CR-1205(1). May 1968.
Effective Temperature* Loss in Output Loss in Accuracy
75° 3% Negligible
80° 8% 5%
85° 18% 40%
90° 29% 300%
95° 45% 700%
100° 62% >>
105° 79% >>
Cooling Effect
What Affects Thermal Comfort?
Thermal Comfort
Personal Factors
Clothing Insulation (clo)
The amount of thermal insulation a person is wearing. Wearing too much
clothing or personal protective equipment may be a primary cause of heat
stress, even if the environment is not considered warm or hot.
Metabolic Rate (met)
The energy generated from the human body. The more physical work we do,
the more heat we produce. The more heat we produce, the more heat needs to
be lost to prevent overheating.
Environmental Factors
Air Temperature (°F) Temperature of the air surrounding the occupant.
Relative Humidity (%RH) Percentage of water vapor in the air. High humidity environments prevent the
evaporation of sweat from the skin.
Radiant Temperature (°F)
The weighted average of all the temperatures from surfaces surrounding an
occupant. Examples of radiant heat sources include: the sun, fire, electric fires,
ovens, kiln walls, cookers, dryers, hot surfaces, machinery.
Air Velocity (fpm) Rate of air movement given distance over time. Air speed beyond four or five
miles per hour usually offers little, if any, additional cooling benefit.
Cooling Effect
ASHRAE Standard 55 defines the range of indoor thermal environmental conditions acceptable to the majority of
occupants as: “That condition of mind which expresses satisfaction with the thermal environment and is
assessed by subjective evaluation.”
Air Temp. = 85 °F
Mean Radiant Temp. = 80 °F
Air Speed = 20 fpm Relative Humidity = 65%
Metabolic Rate = 1.7 met
Clothing Level = 0.5 clo
PMV: 1.55
PPD: 53%
Does not comply with ASHRAE
Standard 55-2013.
Air Temp. = 85 °F
Mean Radiant Temp. = 80 °F
Air Speed = 300 fpm Relative Humidity = 65%
Metabolic Rate = 1.7 met
Clothing Level = 0.5 clo
PMV: 0.42
PPD: 9%
Does comply with ASHRAE
Standard 55-2013.
1Source: ASHRAE. “ANSI/ASHRAE Standard 55-2013.” American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 2013.
ASHRAE’s Thermal Comfort Tool:
Thermal Equalization
Risk Management
• Improve air circulation
• Manage condensation
– Sweating Slab Syndrome
– Mold & pathogens
– Product degradation
• Offset Coanda Effect
Energy Efficiency
HVLS fans are the most efficient and effective air
distribution system ever imagined.
Let’s compare two options for moving 100,000 cu. ft. of air
Fan Number of Fans
Total Watts Used
Time to Circulate Air
24-ft. HVLS Fan 1 1,650 17 seconds
4-ft. High Speed Fan (¾ hp motor)
10 5,595 60 seconds
The greater the CFM per watt ratio, the less electricity it takes to move air.
Energy Efficiency
Reduce Carbon Footprint
Supplement HVAC with HVLS
• Lower HVAC costs
– 25% heating
– 30% cooling
• Reduce tonnage & ducting
– Lower installation costs
– Lower equipment costs
• Meet green building codes, standards,
and guidelines
• Lower carbon footprint in manufacturing
process and daily usage
Product Design
Product Design
Blade Design
• NASA inspired airfoil
– Aerospace aluminum
• Stronger
• Lighter
• Anodized
– Smooth
– Minimize dust buildup
• Requires less torque
– Longer life span
Product Design
Motor Type 1: Gear Driven
• How it works: Gear reduction to
attain high torque
• Dozens of moving parts
• Separate VFD
• Bulky and unbalanced
• Noisy
• Requires oil
• 63% system efficiency
Product Design
Motor Type 2: Traditional DC
• How it works: Strong permanent magnets
on the rotor and electromagnetic windings
on the stator
• More poles added for higher torque
– Increased motor size
– Increased copper for windings
– Increased cost
• Prohibitively large and expensive
Stator of a Traditional Brushless DC Motor
Product Design
Motor Type 3: Transverse Flux Brushless DC
• How it works: Motor coil is a simple copper
ring
• 3x continuous torque as traditional DC
• Less copper wiring
– Reduced electrical losses from resistance
• 1/3 the size of traditional DC
• Lighter weight
• No maintenance
• Quiet
• 77% system efficiency
– (15% higher than gear driven)
Motor Coil of Transverse Flux Brushless DC
Product Design
Custom Drive
• Eliminates Variable Frequency Drive
• Incorporated into the motor housing
• Accepts wide range of voltages
• Input voltage sensing
• Motor self-protect
• Blade length adjustability
Product Design
Electro-mechanical efficiency
comparison: How well the drive
and motor system transfer
electrical energy to mechanical
energy.
• Direct drive motor efficiency is
particularly apparent at lower
speeds.
Product Design
Integration with BMS
• Analog (Wired)
– 2 digital outputs (FOR/REV)
– 1 analog output (0-10 vdc)
• Gateway (Networked)
– Protocol converter from ModBus to
BacNet or Lonworks
• Supervisory
– Enable/disable signal from remote source
Industry Standards
Industry Standards
AMCA: Air Movement & Control Association
• International Certified Ratings Program,
established in 1955.
• Provides system of accountability for air
movement and control products.
• AMCA certified rating provides assurance
that a company’s published ratings are
reliable and accurate.
Industry Standards
UL: Underwriters Laboratories
• Global independent safety science
company that tests, audits, and validates
products.
• Promotes safe living and working
environments.
• UL certified products are tested for
performance and safety based upon
product performance claims.
Industry Standards
NFPA: National Fire Protection Association
• NFPA 13 states that HVLS fans must:
– Not exceed a diameter of 24 feet
– Be centered approximately between
four adjacent sprinklers
– Have at least 3 feet of vertical
clearance from the sprinkler deflector
– Be interlocked to shut down
immediately upon receiving a water
flow signal from the alarm system
LEED Credits
LEED Credits
HVLS Fans & LEED
• Energy efficiency and environmental
benefits of HVLS fans make them a
strategy for earning LEED certification.
• In moderate climates, the cooling effect
can minimize or even eliminate HVAC.
• Integral part of low energy consumption
strategy.
LEED Credits
LEED v4: Possible Point Contributions with HVLS • Energy & Atmosphere
LEED Credit Intent
EA Prerequisite: Minimum Energy Performance
To reduce the environmental and economic harms of excessive energy
use by achieving a minimum level of energy efficiency for the building and
its systems.
EA Credit: Optimize Energy Performance
To achieve increasing levels of energy performance beyond the
prerequisite standard to reduce environmental and economic harms
associated with excessive energy use.
EA Credit: Demand Response
To increase participation in demand response technologies and programs
that make energy generation and distribution systems more efficient,
increase grid reliability, and reduce greenhouse gas emissions.
EA Credit: Enhanced Refrigerant Management To reduce ozone depletion and support early compliance with the
Montreal Protocol while minimizing direct contributions to climate change.
LEED Credits
LEED v4: Possible Point Contributions with HVLS • Indoor Environmental Quality
LEED Credit Intent
EQ Prerequisite: Minimum Indoor Air Quality
Performance
To contribute to the comfort and well-being of building occupants by
establishing minimum standards for indoor air quality (IAQ).
EQ Credit: Enhanced Indoor Air Quality Strategies To promote occupants’ comfort, well-being, and productivity by
improving indoor air quality.
EQ Credit: Thermal Comfort To promote occupants’ productivity, comfort, and well-being by
providing quality thermal comfort.
LEED Credit Intent
IN Credit: Innovation To encourage projects to achieve exceptional or innovative
performance.
• Innovation
Thank You!
Resources
AMCA International. “U.S. Fan Efficiency Codes and Standards: Where Are We Now?” Code Watch USA. AMCA.org, 2014. http://www.amca.org/pdf/codewatch_v7.pdf Accessed September 2015.
ASHRAE. “ANSI/ASHRAE Standard 55-2013.” American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 2013.
ASHRAE. “Thermal Comfort Tool.” 2011. https://www.ashrae.org/resources--publications/bookstore/thermal-comfort-tool?utm_source=promotion&utm_medium=landingpage&utm_campaign=86179&utm_term=86179&utm_content=86179 Accessed September 2015.
Bottomley, T.A., E.M. Roth. “Compendium of Human Responses to the Aerospace Environment.” 6. Thermal Environment. NASA CR-1205(1). May 1968.
Center for the Built Environment. “CBE Thermal Comfort Tool.” 5/1/2014. http://www.cbe.berkeley.edu/research/thermal-tool.htm Accessed September 2015.
Ivanovich, Michael. “How to Specify AMCA-Certified Products.” Arlington Heights, IL: AMCA International, 2014. http://www.amca.org/resources/AMCA_CRP_whitepaper.pdf Accessed September 2015.
MacroAir Technologies Inc. www.macroairfans.com Accessed September 2015.
NFPA. “NFPA 13: Standard for the Installation of Sprinkler Systems.” 2013. http://www.nfpa.org/codes-and-standards/document-information-pages?mode=code&code=13 Accessed September 2015.
USGBC. “LEED Credit Library.” http://www.usgbc.org/credits Accessed September 2015.
1. Which of the following currently represents the largest market for HVLS fans?
A. HVAC (climatized)
B. Automotive
C. Agriculture
D. Warehousing and distribution
2. In large rooms, undisturbed air will stratify into different temperature layers with relatively warmer temperatures near the floor and cooler temperatures near the ceiling.
A. True
B. False
3. HVLS fans create airflow with wind speeds that are:
A. Faster than traditional high speed fans
B. Slower than traditional high speed fans
C. Comparable to traditional high speed fans
D. So slow they are completely unnoticeable by occupants
Quiz
4. All of the following statements about air columns are TRUE EXCEPT:
A. The air column from a three-foot diameter fan has more than six times as much friction interface per cubic foot than does the air column from a 20-foot fan.
B. The friction between moving air and stationary air occurs at the periphery of the moving column.
C. Because larger diameter fans generate much larger columns of moving air than smaller high speed fans, there is more surface area on the outside of the air column to absorb the friction.
D. The air flowing outward from the column is called the “horizontal floor jet.”
5. HVLS fans help improve air quality by:
A. Efficiently circulating and mixing the air in large volumes
B. Improving general occupant comfort and air quality, by improving the air exchange system’s
Effectiveness
C. Thermally equalizing the interior masses, minimizing humidity migration, and reducing condensation
D. Reducing energy consumption, thus reducing the carbon footprint and stewarding all mankind
E. All of the above
Quiz
6. HVLS fans provide an efficient and effective way to provide lower humidity and lower temperature to an interior space.
A. True
B. False
7. The benefits of a traditional HVAC system supplemented with HVLS fans include which of the following?
A. Improved energy efficiency
B. Increased component size
C. Lowered HVAC costs
D. All of the above
E. A and C only
8. When comparing the new Brushless Trans Flux DC motor to conventional HVLS systems:
A. The Trans Flux DC has more torque throughout the full range of speed.
B. The Trans Flux DC produces air at a 17% increase to electromechanical efficiency.
C. The Trans Flux DC requires more copper wiring.
D. All of the above.
Quiz
9. All of the following statements about fan motors are TRUE EXCEPT:
A. A D-drive transverse flux motor is three times smaller yet five times more powerful than a traditional brushless DC motor.
B. A D-drive transverse flux motor moves air more efficiently and generates more wind power at the same speed as other HVLS fans.
C. Traditional brushless DC motors are commonly used for fans larger than 20 feet in diameter.
D. A D-drive transverse flux motor is gearless and therefore does not require maintenance.
10. The intent of this LEED® credit is to achieve increasing levels of energy performance beyond the prerequisite standard to reduce environmental and economic harms associated with excessive energy use.
A. EA Prerequisite: Minimum Energy Performance
B. EA Credit: Optimize Energy Performance
C. EQ Credit: Enhanced Indoor Air Quality Strategies
