Page 12A
NEWSfrom FRACCA Ht = Hs + Hl
continued from page 11A
Ht = 1,083 + 3,399… 5,381 Btuh
Note the SHR (Sensible Heat Ratio) (Hs/Ht) of this load… 0.37 or heavily latent.
Think
high humidity. Question: If you are pumping water into
Florida HVAC Insider
the building, what is your plan to pump the water out? Knowing that our job as A/C people is to provide COMFORT and not just install “Boxes”; what is your plan to deal with this new scenario? Some say, “I just use 500 square feet per ton and it always works!” If that is your plan, stop reading now; this
article is not for you. If how- ever, the numbers above give you pause, and they should, please continue reading. As the house gets tighter and the indoor humidity levels increase above the range of 50-55% you will (not might) start to experience odor prob- lems. Little organic friends are multiplying and a method(s) to limit them and the subsequent odors must be employed. ASHRAE 62 is about how many
air changes of fresh outdoor air are necessary to limit the smell. Note the standard also pres- ents the probability that you will need to change the equipment you select to match this new, much higher latent load. The necessary equipment data is NOT found in the AHRI, but rather the manufacturer’s ex- panded cooling performance data. To maintain the desired indoor rh (relative humidity) and minimize organic growth
February 2015
you MUST employ equipment with lower SHRs. Variable Speed AHU (air handlers) will be virtually a standard item as they are a good start to lower SHRs. There are other strategies that may be neces- sary depending on the exact circumstances of each house. An accurate Heat Gain calcu- lation is a must to determine the correct size and 500 sq ft/ ton isn’t an acceptable sizing method. Would you go to a doctor that was locked in to 1975 methods? No, and neither should you be locked into A/C methods from that era. This is a teaser, something to get you thinking about a strategy to deal with this ever increasing problem. There will be more at the FRACCA Education Conference March 27-28, 2015 in Orlando. Topics and particulars are available online or call the FRACCA offi ce 727- 576-3225. FRACCA looking out for
you, Bob Cochell
Guest column written by Bob Cochell, a FRACCA Board member and member of the Energy Technical Advisory Committee of the Florida Build- ing Commission. If you have questions or have feedback to give on this article, contact your local chapter offi ce, or contact the FRACCA execu- tive offi ce at
mail@fracca.org or 727-576-3225.
continued from page 5A Gemaire
space provides more clear- ance for brazing line sets and attaching gauges. Condensers feature the industry’s widest control box, 15 inches, which opens by removing only 2 fasteners. The composite base pan features molded-in hand grips for easy handling and molded -in screw trays for convenience.
360° Serviceability™: Self- diagnostics and other smart- servicing features and Triple Service Access: Two fastener removal provides industry best 15” wide access to the control box; the entire corner panel can be removed, providing unparalleled access to internal components; and single fas- tener removal of louver panels for easy coil cleaning. 360° Integration™: At home and on-the-go control of set- tings, energy savings, service alerts and more. The EcoNet™ system allows for future in- tegration with other Rheem appliances, such as heating and cooling systems, pool and spa heaters, and remote access tools. It is also future- compatible with home automa- tion, energy management and demand response systems. And there’s 360° Partner- ship™: Professional support from the names dealers trust: Rheem and Gemaire. See photos from the meet- ings on pages 3C, 4C and 5C.
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