03-02-2015 Council Packet - Laserfiche WebLink

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insulated glass. High-speed coiling doors being considered for this project have a U -value of 1.20 for an uninsulated door with double pane glazing. Neither U -value is exceptional, but the four -fold door is almost three times better than the high-speed coiling door. The energy efficiency benefits of high-speed coiling doors are based on the amount of heat lost during the open period which is greatly reduced due to the high speed of the opening process. Doing additional research an article addressing this was found in the February, 2015, issue of Construction Specifier magazine just published this month. This article documents a study done on energy efficiency of high-speed coiling doors as compared to sectional doors. The conclusion of the study is highlighted in the table at left indicating that the energy conservation breakpoint between high- speed coiling doors and conventional doors is at an operation of 55 cycles per day. Since the fire station is anticipated to only have a very small fraction of that many daily cylces, the U -value is much more important than speed for energy conservation resulting in the four -fold door being a better energy efficiency choice for a fire station. Conversely, for the more common installation at auto dealership service reception doors where cycles are more commonly in the 100+ cycles per day, the high-speed coiling door would be the best energy performer. 30000 } ▪ 15,000 c � 20,000 7, mow 1• 5,000 3 t 43 5000 Annual Energy Consumption in Chicago for a r R8' Door (Facility Heated Only) 0 20 40 60 80 100 120 140 160 180 200 Number of Cycles Per Day —High Performance Door ,Conventional Door • Breakeven at 55 Cycles per Day Based on the test conditions, a high-speed door becomes more energy efficient versus a conventional door after 55 cycles. Visual Impact: Aesthetically, the high-speed coiling doors differ in two ways from the four -fold doors specified in the original design. First, the window pattern in the high-speed coiling door is different as each section of door is 9" or 10" tall (depending on manufacturer) with about a 6" to 7" glass strip centered in the panel. The four -fold door designed for this project has two large glass windows in each of its four panels resulting in a different look and a higher percentage of glass providing more visibility of the apparatus inside the station. Secondly, the four -fold door opens horizontally stacking inside the building at each side of the door opening. The door panels when open are protected by 6" steel bollards. The high-speed coiling door rolls up into a 3 foot deep by 3 foot tall box at the head of the door. This box sticks up into the window opening designed to be over the doors. If this door style is selected we would raise the sill of the windows at the three coiling doors in order to appropriately address this change. The following page shows renderings of the front of the fire station with each type of door for your review. P:\PROJECTS\2014\14045\4 - BIDDING\ALTERNATE 45 RECOMMENDATIONS.DOCX