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Question:
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Does Spec-Air build energy recovery equipment?
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Answer:
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Yes, we use our E2PAK exchanger that we use for the indirect evaporative cooler. We take the return air from the building in both summer and winter and run it through the exchanger to pick up the energy that would be lost to the outdoors and return it back to the building when make-up air is required.
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Question:
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Can you pick up LEED points by using Indirect Evaporative Cooling?
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Answer:
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Technically you don’t get points directly, you get points by showing energy efficiency greater that a standard baseline building, it works on a percentage better than ASHRAE 90.1/ Title 24, and IDEC can help you achieve the higher efficiency.
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Question:
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How cost effective are Indirect Evaporative Coolers?
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Answer:
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They can have higher first costs verses typical packaged mechanical equipment, but based on the energy savings typical ROI is one to three years.
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Question:
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Are Evaporative Coolers Reliable?
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Answer:
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Evaporative Coolers are very reliable, they typically consist of a fan, motor, pump and float. With regular maintenance they will last for years.
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Question:
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Does Evaporative Cooling harm the environment?
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Answer:
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Evaporative Cooling is Nature’s way to cool; it is very efficient and uses a fraction of the electrical energy of mechanical cooling systems. Evaporative Cooler use water as the transfer media verses ozone depleting refrigerants, even the new ozone friendly refrigerants can still harm the environment.
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Question:
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How much energy can I save by using Evaporative Cooling?
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Answer:
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Depending on where you are located you can expect to save 35 to 65% compared to mechanical cooling.
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Question:
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What Cooling would I get combining Indirect and Direct Evaporative cooling?
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Answer:
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If we use the above example starting with 100⁰F Dry Bulb and 70⁰F Wet Bulb running through the Indirect Evaporative Cooler first we get the 76⁰F Dry Bulb and 62⁰F Wet Bulb. We then pass the air through a Direct Evaporative Cooler at 90% our final temperature is 63.5⁰F Dry Bulb and 62⁰F Wet Bulb. The air is very humid but the temperature has dropped 36.5⁰F. This saves 3.22Tons of mechanical cooling for every 1,000CFM of air.
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Question:
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What Cooling Efficiency can I get with Indirect Evaporative Cooling?
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Answer:
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Again efficiency will vary depending on the type of energy exchanger being used but typically you can expect between 70 to 80%. If we take the same 100⁰F Dry Bulb and 70⁰F Wet Bulb and an exchanger with 80% efficiency the supply air temperature will be S/A=100-[0.8(100-70)] or 76⁰F Dry Bulb and 62⁰F Web Bulb. We have done sensible cooling and not added any moisture to the air so our humidity is only 48%.
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Question:
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What type of Cooling Efficiency can I get with Direct Evaporative Cooling?
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Answer:
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Efficiency can vary depending on a number of factors; using Direct Evaporation with a typical 12” deep media will give you saturation efficiency of 80 to 90%. For example let take a summer day with a temperature of 100⁰F Dry Bulb and 70⁰F Wet Bulb entering the unit with 90% efficiency the air being supplied would be reduced 90% of the difference between the two temperatures or S/A= 100-[0.9x(100-70)] or 73⁰F Dry Bulb and 70⁰F Web Bulb, but you have 90% humidity.
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Question:
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What is Indirect Evaporative Cooling?
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Answer:
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Indirect Evaporative Cooling also known as Sensible Cooling uses a energy exchanger which has two air streams, the supply air that is being cooled and the waste or exhaust air stream that does the evaporation. For example let say you have a flat sheet of metal, on one side you wet the surface and pass air over it which evaporates the water and cooling the surface of the plate same as your skin in the previous answer. Then the hot supply air is passed over the dry side of the metal sheet which have been cooled by evaporation, thus cooling the supply air.
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Question:
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What is Direct Evaporative Cooling?
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Answer:
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Direct Evaporative Cooling is also called Adiabatic Cooling, it occurs when air is passed over a wetted media and cooling that air by evaporating the water adding humidity to the air and approaching the wet bulb temperature or dew point, this works much like when you perspire or get out of a pool on a windy day, even though the air is hot you get cold due to evaporation.
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