Beyond the
Tulane Study  "Cool-n-Save can lower the cost of running HVAC systems by as much as 30%" and "Cool-n-Save can reduce energy consumption of HVAC systems up to 30%" are not just idle claims. They are based on real world results, not superlatives and speculation. Some research - in particular the one from Tulane University - have fund that, under certain conditions, savings might even be greater than 30%. The study itself can be found HERE. No doubt, the Tulane study was a great boost for Cool-n-Save development team, but some of those findings presented a bit of a conundrum for the marketing department at Greenway Design Group. Amid the observed gained efficiencies from pre-cool AC misting, the Tulane researchers observed that Cool-n-Save increased heat flux by 170%. Since heat flux is a measurement of HVAC efficiency, this conclusion might seem incredible were it not based on the results of a controlled laboratory experiment.And that's where the conundrum started. The first reaction by our marketing department was to take up the claim that Cool-n-Save "increases efficiency by 170%." However, cooler heads prevailed and Ben Lefrancois and Darius Jakubik decided to take a more conservative course. Rather than suggest very high (and unreasonable) expectation for energy savings, the company went beyond the Tulane study and relied on the real world results. In so doing, we also burdened ourselves with taking in all of the variables and conditions that can affect Cool-n-Save performance. For instance, weather and climate have significant impact on performance. Warmer, dryer conditions tend to generate the best results (e.g., the upper end of the savings scale) while cooler, wetter conditions do not (e.g., lower end of the savings scale). Then there's the location, size and condition of the condenser unit. Smaller, older units that are poorly maintained will not produce the same level of savings of larger, better-maintained or newer units. We found that there are far too many variables to make blanket, unconditional claims. We found the answer from our clients: people were saving "up to 30%" on the cost of running their HVAC system (the average saving is about 25%). According to EIA data (Energy Information Administration), electricity for HVAC alone can be 25 to 50% of the monthly cost of building operations (depending on local electricity rates). That means many of our clients see reduced overall energy consumption from 7 to 15%, which in any economy is a huge dividend. | | Why Cool-n-Save works:
The science behind the savings. Ambient air temperature has a direct correlation on efficient heat transfer from the refrigerant in AC systems. The cooler the air, the faster heat moves out of the system. Cool-n-Save immediately decreases air temperature by about 30% which means greater efficiency in overall HVAC performance. | Heat is often loosely referred to as thermal energy. However, the scientific definition of heat requires that energy be actually in the process of movement from one object to another. While this may seem like a quibble over details, the particular point of interest in the Tulane study is heat flux - or the rate in which heat travels. Thermodynamics (the study heat energy) is the underlying reason why HVAC works the way it does. To truly understand the work that is going on behind the condenser coils of your air conditioner, there are several laws of thermodynamics to consider. One is the fact that the energy of an isolated object is "conserved" and may remain constant. Another law observes that heat transfer occurs only in the direction of the colder object. For most air conditioning systems, that 'colder object' is the air that surrounds the outside condenser coils. If we want to get rid of the heat that collects in the refrigerant in the coils, we want to promote heat transfer - or heat flux. Promoting heat flux means allowing spontaneous flows of energy from one object of a high temperature (e.g., refrigerant inside the coils) to one that has a lower temperature (e.g., the outside air). Therefore, the lower the outside air temperature (ambient air temperature), the faster heat can move (the greater the heat flux). By extrapolation, this leads us to the potential energy-efficiencies gained by Cool-n-Save. By spraying micro water mist into the air around the HVAC unit, we ensure that the heat ratio between the coolant and the fins is as large as possible. Ambient air temperature has a direct correlation on efficient heat transfer from the refrigerant in AC systems. The cooler the air, the faster heat moves out of the system. Cool-n-Save pre-cool AC mist immediately decreases air temperature by about 30% which means greater efficiency in overall HVAC performance. The Cool-n-Save Solution Greenway solved the "hot air" problem by injecting treated water mist into the air around the outdoor coils. As most of the mist evaporates instantly, creating what we call a pre-cool shield. Inside the 'shield', the air temperature can be 30°F lower than surrounding ambient air. For instance, if the ambient air temperature is 98°F, the mist will knock it down to approximately 68°F. According to a white paper published by Colorado Springs Utilities in 2005, for every degree Fahrenheit reduction in ambient air temperature, a reduction of 1 to 1.5% in energy demand is realized. Thus, cooler ambient air dramatically increases the EER (Energy Efficiency Rating) of the air conditioning system. The system runs more efficiently and less frequently, thus less energy is used for GREATER cooling power. Third-party tests have shown that Cool-n-Save® Evaporative Pre-Cool Systems produce up to 30% savings on energy use; the average is around 26% depending on climate, and the conditions and size of the system (the larger the system, the greater the potential energy savings). Cool-n-Save also helps reduce wear and tear on equipment (thanks to gained efficiency) which leads to lower overall cost for repair and replacement. A detailed analysis of how Cool-n-Save improves the efficiency of air conditioning condenser units was conducted by the Department of Mechanical Engineering at Tulane University in Louisiana in 2005 (see sidebar "Beyond the Tulane Study"). In the 29-page report, researchers concluded that Cool-n-Save "substantially" increases heat transfer of air conditioning units and "that cooler air will be able to circulate throughout a structure and that this will decrease the time the condenser unit runs thus reducing electricity cost to the user." A separate study presented in 2009 during an international conference held in Glasgow, Scotland by researchers from Hong Kong Polytechnic University confirms that the application of water mist to pre-cool "ambient air" increases performance and efficiency of air conditioning systems by 30% or more. Subsequent system field tests of Cool-n-Save installations show instant and sustainable reduction of energy consumption - on average about 26%, with peak savings of more than 30%. Greenway was also recently declared the winner of TechAmerica's 18th Annual High-Tech Innovation Awards for "Green Engineering" from Harvey Mudd College. Cool-n-Save was recognized as an innovation that has wide reach and high potential to significantly reduce energy consumption wherever air conditioning systems are used. According to researchers at UC Davis, the world NEEDs innovations like Cool-n-Save. HVAC operations account for more than 25% of electricity consumption in California alone. In climates where heat is more intensive (e.g, the U.S. "sunbelt region", Central America, South America), HVAC operations can account for more than 40% of annual energy consumption. The California Energy Commission California Commercial End-Use Survey (CEUS) reports that roughly 65% of commercial floor area is cooled by 'split system' packaged rooftop units. About 80% of the individually connected air conditioning systems fall in this category. Greenway's Cool-n-Save pre-cool system is proven to be the first economically viable, turnkey commercial solution that increases efficiency of split system HVAC by as much as 30%. This level of efficiency improvement will be essential to reach energy efficiency goals set by national, state policies and throughout the business community. |
