INTRODUCTION
Energy is expensive, especially when it comes to heating and cooling. Whether you do business in the north- east or the south, you’re most likely looking for ways to lower your energy costs. In addition, businesses are under the gun from federal, state, and even supply chain partners and customers to lower their carbon footprint and develop and implement “green” practices and products. Wal-mart’s stated objective, for example, is to “accelerate change towards sustainability”, which means that any company doing business with Wal-mart will have to show demonstrable eco-improvements, whether it’s in the manu- facturing of goods or the distribution and warehousing of these goods.We at MacroAir Technologies have been under the same pressures. In 2005, we set out to reduce our own carbon footprint and that of our customers’ by making our High Volume Low Speed (HVLS) commercial ceiling fans more efficient. We started with the possibility of changing the airfoil shape of the fan blades. We knew that extrusion capacities had changed, giving us the ability to extrude a larger shape. Thus, we wanted to create a new, larger blade shape that would function efficiently through a wide range of speeds.
We also asked ourselves if we could reduce the number of fan blades without affecting performance. Our founder, Walter Boyd, developed the original 10-blade HVLS fan in 1995. This 10-blade design was extraordinary at the time, as nothing like it existed; since then, thousands of agricultural, manufacturing, and commercial enterprises across the U.S. have installed these fans in order to reduce energy costs and improve heating and cooling. Thus, our objectives became:

Create a larger airfoil shape
Reduce the number of blades to make the fan lighter and more efficient
Lower our carbon footprint

After months of research, design, experimentation, and testing, the result was a completely new six-blade HVLS fan; one that was lighter, more efficient, and better performing.

In this white paper you will learn about the history of HVLS fan technology and how six-blade HVLS fans improve energy efficiency, lower costs, and reduce the carbon footprint for both us, as the manufacturers, and our customers.

HISTORY OF HVLS FANS

An inventor his entire life, MacroAir founder Walter Boyd was challenged to help create an efficient system to cool dairy cattle. The problem: dairy cattle stop eating when they suffer from heat stress. When they don’t eat, milk production slows or comes to a halt, a bottom-line breaking challenge for dairy farmers in an already highly competitive business. At the time, small high-speed fans helped, but posed their own challenges: they didn’t cover a wide enough area, were considerably less efficient, consumed excessive and costly energy, and required ongoing maintenance. They also had a short mechanical life.

Taking advantage of the laws of physics, Walt designed a large, slow moving overhead fan that moved a large volume of air gently down to the ground and outward 360 degrees. This large, slow moving air mass moved throughout the barn, continuously mixing incoming fresh air with stale air and minimizing the amount of ventilation required to achieve good air quality. Most importantly, the new fans cooled the cows without causing them stress due to excessive noise or kick-up of dust, and thus increased milk production. The first High Volume, Low Speed (HVLS) barn fan models (AirvolutionTM and MaxAirTM) used 10 airfoil blades that incorporated design characteristics developed at NASA.