PROJECT SUPPORT STATEMENT DEVEPLOMENT APPLICATION FOR VERIZON SITE MOSQUITO ROAD APN: 050 420 34 10 1070 Meadow Lane Court, Placerville, CA. 95667 INTRODUCTION Verizon Wireless is seeking to improve communications service in the El Dorado County area near Mosquito Rd. in Placerville. Verizon would like to increase coverage and capacity in the area by constructing a new telecommunications facility in to improve service for both current and potential customers. Additionally, this network development will increase public safety within these areas and bring wireless and broad band service, to areas that currently have poor capacity service. This tower will help alleviate an area of poor coverage and inadequate capacity within this service area, which causes reoccurring lost calls and ineffective service. This site will relieve inadequate capacity in the area due to high cell phone usage along Mosquito Rd. and will also improve service in the town of Placerville and outlying areas within the proposed service area. The proposed location of the tower is set within an unutilized portion of this parcel and will be designed to comply with the City of Placerville s general plan. The proposed Verizon Communications facility will include: a 20 x30 steel platform, encircled by a wooden fence to provide screening of the equipment cabinets and a 30kVA emergency standby generator. In addition an 90 stealth, monopine will be located adjacent to the platform and will include (4) antenna sectors with (2) antennas per sector, (2) remote radio units (RRU s) per sector (total is 8). This tower has been designed to accommodate future collocation by other carriers. The parcel select selected for this communication is owned by, El Dorado Irrigation District, a public entity and totals 2.40 acres. The location for this project is situated approximately 852 from Mosquito Road. The project will employ a stealth monopine that will blend in with the large trees nearby. This unmanned facility will provide service to area travelers, residents and businesses 24 hours a day, 7 days a week. This site will also serve as a back up to the existing landline service in the area and will provide improved mobile communications, essential to modern day commerce and recreation. This tower has been designed at the following height for the following reasons. 1. The signal from the proposed tower mounted antennas needs to be high enough to clear all near field obstructions such as trees, water tank and adjacent hills, in order to effectively communicate with other antennas in the Verizon network. In addition the 90 overall height is required in order to adequately serve the intended coverage area in this portion of the Verizon network. Stated differently, a 40 height would not provide the required clearance of the before mentioned obstructions or provide the required visibility of outlying areas required of a telecommunication site at this location. 2. In addition, the fact that the tower is designed as a monopine, rather than a conventional tower, requires that an additional 5 in height be added to the tower to accommodate a crown in order to better approximate the natural appearance of a pine tree. 3. Furthermore, this tower has been design to accommodate future additional carriers and the requisite clearance between antenna centerlines and the proposed microwave antenna. This is a required design feature of all new towers in El Dorado County and is intended to encourage collocation on existing towers, rather than the construction of new communication facilities. Project Support Statement Verizon Mosquito Road Site
SAFETY BENEFITS OF IMPROVED WIRELESS SERVICE Mobile phone use has become an extremely important system for public safety. Along roads and highways without public call boxes, mobile phones are often the only means for emergency roadside communication. Motorists with disabled vehicles (or worse) can use their phone to call in and request appropriate assistance. With good cellular coverage along important roadways, emergency response is just a phone call away. Furthermore, as a back up system to traditional landline phone service, mobile phones have proven to be extremely important during natural disasters and other catastrophes. Verizon has taken the responsibility for back up service very seriously. As such, Verizon has incurred increased expense to install a standby diesel generator at this facility to insure quality communication for the surrounding community regardless of any disaster or catastrophe. CONVENIENCE BENEFITS OF IMPROVED WIRELESS SERVICE Modern day life has become increasingly dependent on instant communications. Whether it is a parent calling their child, spouse calling a spouse, or general contractor ordering materials to the jobsite, wireless phone service is no longer just a convenience. It has become a way of life and a way of business. COMPLIANCE WITH COUNTY DEVELOPMENT STANDARDS Per the City of Placerville general plan section 10 3 4 confirms that the following uses are permitted in ANY ZONE: Communication equipment buildings Public utility or public service buildings and uses Radio, microwave, television and telephone transmitter and broadcasting stations, including amateur and professional In addition, the existing water tank storage facility has already compromised the exiting parcel with large, commercial water storage tanks. The proposed cell tower has been designed as a stealth monopine, with all antennas and associated equipment screened by branches and antenna socks. In addition the site has been designed to conform with the City of Placerville noise standards (See attached noise study). COMPLIANCE WITH FCC STANDARDS This project will not interfere with any TV, radio, telephone, satellite, or any other signals. Any interference would be against the Federal Law and would be a violation Verizon Wireless FCC License. In addition, this project will conform to all FCC standards. TECHNOLOGY AND CONSUMER SERVICES THE CARRIER WILL PROVIDE ITS CUSTOMERS Verizon offers its customers multiple services such as, voice calls, text messaging, mobile email, picture/video messaging, mobile web, navigation, broadband access. Wireless service enhances public safety and emergency communications in the community. In rural areas such as the subject location, cellular phone service can cover much larger geographic areas than traditional landline phone service. FUTURE COLLOCATION OPPORTUNITIES The proposed site has been designed to allow for future co location opportunities with other carriers. The land lease provides sufficient space for additional service providers and the tower and its foundation are designed for future equipment. This tower will eliminate the need for multiple towers within the same Project Support Statement Verizon Mosquito Road Site 2
general vicinity as it has been designed to accommodate up to (3) carriers and their associated ground equipment. LIGHTING Unless tower lighting is required by the FAA the only lighting on the facility will be a shielded motion sensor light by the door on the equipment shelter for servicing the equipment. NOISE The standby generator will be operated for approximately 15 minutes per week for maintenance purposes, and during power outages and disasters. HAZARDOUS MATERIAL A Hazardous Material Business Plan will also be submitted upon project completion, and stored on site after construction ENVIRONMENTAL SETTING The site is set within a parcel that is zoned for R 1, 20,000 (Single Family residential zone) and is consistent with application design standards in the area and environment. MAINTENANCE AND STANDY GENERATOR TESTING Verizon installs a standby diesel generator and batteries at many of its cell sites. The generator and batteries serve a vital role in Verizon emergency and disaster preparedness plan. In the event of a power outage, Verizon communications equipment will first transition over to the back up batteries. The batteries can run the site for a few hours depending upon the demand placed upon the equipment. Should the power outage extend beyond the capacity of the batteries, the back up generator will automatically start and continue to run the site. This two state back up plan is an extremely important component of Verizon communications sites. Back up batteries and generators allow Verizon communications sites to continue providing valuable communications services in the event of a power outage, natural disaster or other emergency. A standby generator will be installed at the site to ensure quality and consistent coverage in the event of a power outage or disaster. This generator will be run for approximately 15 minutes per week for maintenance purposes, and during power outages and disasters. A technician will visit the site approximately twice a month to check the facility and perform any necessary maintenance. CONSTRUCTION SCHEDULE The construction of the facility will be in compliance with all local rules and regulations. The typical duration is two months. The crew size will range from two to ten individuals. Project Support Statement Verizon Mosquito Road Site 3
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California Statement of Hammett & Edison, Inc., Consulting Engineers The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of Verizon Wireless, a personal wireless telecommunications carrier, to evaluate the base station (Site No. 279040 Mosquito Road ) proposed to be located at 1070 Meadow Lane Court in Placerville, California, for compliance with appropriate guidelines limiting human exposure to radio frequency ( RF ) electromagnetic fields. Executive Summary Verizon proposes to install directional panel antennas on a tall pole to be located at 1070 Meadow Lane Court in Placerville. The proposed operation will comply with the FCC guidelines limiting public exposure to RF energy. Prevailing Exposure Standards The U.S. Congress requires that the Federal Communications Commission ( FCC ) evaluate its actions for possible significant impact on the environment. A summary of the FCC s exposure limits is shown in Figure 1. These limits apply for continuous exposures and are intended to provide a prudent margin of safety for all persons, regardless of age, gender, size, or health. The most restrictive FCC limit for exposures of unlimited duration to radio frequency energy for several personal wireless services are as follows: Wireless Service Frequency Band Occupational Limit Public Limit Microwave (Point-to-Point) 5,000 80,000 MHz 5.00 mw/cm 2 1.00 mw/cm 2 BRS (Broadband Radio) 2,600 5.00 1.00 WCS (Wireless Communication) 2,300 5.00 1.00 AWS (Advanced Wireless) 2,100 5.00 1.00 PCS (Personal Communication) 1,950 5.00 1.00 Cellular 870 2.90 0.58 SMR (Specialized Mobile Radio) 855 2.85 0.57 700 MHz 700 2.40 0.48 [most restrictive frequency range] 30 300 1.00 0.20 General Facility Requirements Base stations typically consist of two distinct parts: the electronic transceivers (also called radios or channels ) that are connected to the traditional wired telephone lines, and the passive antennas that send the wireless signals created by the radios out to be received by individual subscriber units. The transceivers are often located at ground level and are connected to the antennas by coaxial cables. A small antenna for reception of GPS signals is also required, mounted with a clear view of the sky. Because of the short wavelength of the frequencies assigned by the FCC for wireless services, the Q2T5 Page 1 of 3
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California antennas require line-of-sight paths for their signals to propagate well and so are installed at some height above ground. The antennas are designed to concentrate their energy toward the horizon, with very little energy wasted toward the sky or the ground. This means that it is generally not possible for exposure conditions to approach the maximum permissible exposure limits without being physically very near the antennas. Computer Modeling Method The FCC provides direction for determining compliance in its Office of Engineering and Technology Bulletin No. 65, Evaluating Compliance with FCC-Specified Guidelines for Human Exposure to Radio Frequency Radiation, dated August 1997. Figure 2 describes the calculation methodologies, reflecting the facts that a directional antenna s radiation pattern is not fully formed at locations very close by (the near-field effect) and that at greater distances the power level from an energy source decreases with the square of the distance from it (the inverse square law ). The conservative nature of this method for evaluating exposure conditions has been verified by numerous field tests. Site and Facility Description Based upon information provided by Verizon, including zoning drawings by Borges Architectural Group, Inc., dated June 27, 2014, it is proposed to install eight Andrew Model SBNHH-1D65B directional panel antennas on a new 85-foot steel pole, configured to resemble a pine tree, to be sited northwest of the water tank located at 1070 Meadow Lane Court in Placerville. The antennas would be mounted with up to 4 downtilt at an effective height of about 77 feet above ground and would be oriented in pairs toward 80 T, 170 T, 260 T, and 350 T, to provide service in all directions. The maximum effective radiated power in any direction would be 10,310 watts, representing simultaneous operation at 4,620 watts for AWS, 4,310 watts for PCS, and 1,380 watts for 700 MHz service; no operation is proposed in the cellular band. Also proposed to be located on the pole, at an effective height of about 60 feet above ground, is a microwave dish antenna, for interconnection of this site with others in the Verizon network. There are reported no other wireless telecommunications base stations at the site or nearby. Study Results For a person anywhere at ground, the maximum RF exposure level due to the proposed Verizon operation, including the contribution of the microwave antenna, is calculated to be 0.012 mw/cm 2, which is 1.2% of the applicable public exposure limit. The maximum calculated level for a person on the nearby water tank * is 0.67% of the public exposure limit. The maximum calculated level at the * Located at least 80 feet away, based on photographs from Google Maps. Q2T5 Page 2 of 3
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California second-floor elevation of any nearby residence is 0.30% of the public exposure limit. It should be noted that these results include several worst-case assumptions and therefore are expected to overstate actual power density levels from the proposed operation. No Recommended Mitigation Measures Due to their mounting locations, the Verizon antennas would not be accessible to the general public, and so no mitigation measures are necessary to comply with the FCC public exposure guidelines. It is presumed that Verizon will, as an FCC licensee, take adequate steps to ensure that its employees or contractors receive appropriate training and comply with FCC occupational exposure guidelines whenever work is required near the antennas themselves. Conclusion Based on the information and analysis above, it is the undersigned s professional opinion that operation of the base station proposed by Verizon Wireless at 1070 Meadow Lane Court in Placerville, California, will comply with the prevailing standards for limiting public exposure to radio frequency energy and, therefore, will not for this reason cause a significant impact on the environment. The highest calculated level in publicly accessible areas is much less than the prevailing standards allow for exposures of unlimited duration. This finding is consistent with measurements of actual exposure conditions taken at other operating base stations. Authorship The undersigned author of this statement is a qualified Professional Engineer, holding California Registration No. E-20309, which expires on March 31, 2015. This work has been carried out under her direction, and all statements are true and correct of her own knowledge except, where noted, when data has been supplied by others, which data she believes to be correct. February 12, 2015 Andrea L. Bright, P.E. 707/996-5200 Located at least 110 feet away, based on photographs from Google Maps. Q2T5 Page 3 of 3
FCC Radio Frequency Protection Guide The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission ( FCC ) to adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have a significant impact on the environment. The FCC adopted the limits from Report No. 86, Biological Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields, published in 1986 by the Congressionally chartered National Council on Radiation Protection and Measurements ( NCRP ). Separate limits apply for occupational and public exposure conditions, with the latter limits generally five times more restrictive. The more recent standard, developed by the Institute of Electrical and Electronics Engineers and approved as American National Standard ANSI/IEEE C95.1-2006, Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 khz to 300 GHz, includes similar limits. These limits apply for continuous exposures from all sources and are intended to provide a prudent margin of safety for all persons, regardless of age, gender, size, or health. As shown in the table and chart below, separate limits apply for occupational and public exposure conditions, with the latter limits (in italics and/or dashed) up to five times more restrictive: Frequency Applicable Range (MHz) Electromagnetic Fields (f is frequency of emission in MHz) Electric Field Strength (V/m) Magnetic Field Strength (A/m) Equivalent Far-Field Power Density (mw/cm 2 ) 0.3 1.34 614 614 1.63 1.63 100 100 1.34 3.0 614 823.8/ f 1.63 2.19/ f 100 180/ f 2 3.0 30 1842/ f 823.8/ f 4.89/ f 2.19/ f 900/ f 2 180/ f 2 30 300 61.4 27.5 0.163 0.0729 1.0 0.2 300 1,500 3.54 f 1.59 f f /106 f /238 f/300 f/1500 1,500 100,000 137 61.4 0.364 0.163 5.0 1.0 1000 Occupational Exposure Power Density (mw/cm 2 ) 100 10 1 PCS Cell FM 0.1 Public Exposure 0.1 1 10 100 10 3 10 4 10 5 Frequency (MHz) Higher levels are allowed for short periods of time, such that total exposure levels averaged over six or thirty minutes, for occupational or public settings, respectively, do not exceed the limits, and higher levels also are allowed for exposures to small areas, such that the spatially averaged levels do not exceed the limits. However, neither of these allowances is incorporated in the conservative calculation formulas in the FCC Office of Engineering and Technology Bulletin No. 65 (August 1997) for projecting field levels. Hammett & Edison has built those formulas into a proprietary program that calculates, at each location on an arbitrary rectangular grid, the total expected power density from any number of individual radio sources. The program allows for the description of buildings and uneven terrain, if required to obtain more accurate projections. FCC Guidelines Figure 1
RFR.CALC Calculation Methodology Assessment by Calculation of Compliance with FCC Exposure Guidelines The U.S. Congress required (1996 Telecom Act) the Federal Communications Commission ( FCC ) to adopt a nationwide human exposure standard to ensure that its licensees do not, cumulatively, have a significant impact on the environment. The maximum permissible exposure limits adopted by the FCC (see Figure 1) apply for continuous exposures from all sources and are intended to provide a prudent margin of safety for all persons, regardless of age, gender, size, or health. Higher levels are allowed for short periods of time, such that total exposure levels averaged over six or thirty minutes, for occupational or public settings, respectively, do not exceed the limits. Near Field. Prediction methods have been developed for the near field zone of panel (directional) and whip (omnidirectional) antennas, typical at wireless telecommunications base stations, as well as dish (aperture) antennas, typically used for microwave links. The antenna patterns are not fully formed in the near field at these antennas, and the FCC Office of Engineering and Technology Bulletin No. 65 (August 1997) gives suitable formulas for calculating power density within such zones. For a panel or whip antenna, power density S = and for an aperture antenna, maximum power density Smax = 180 BW 0.1 P net D 2 h, in mw /cm 2, where BW = half-power beamwidth of the antenna, in degrees, and Pnet = net power input to the antenna, in watts, D = distance from antenna, in meters, h = aperture height of the antenna, in meters, and = aperture efficiency (unitless, typically 0.5-0.8). 0.1 16 P net h 2, in mw /cm 2, The factor of 0.1 in the numerators converts to the desired units of power density. Far Field. OET-65 gives this formula for calculating power density in the far field of an individual RF source: power density S = 2.56 1.64 100 RFF 2 ERP 4 D 2, in mw /cm 2, where ERP = total ERP (all polarizations), in kilowatts, RFF = relative field factor at the direction to the actual point of calculation, and D= distance from the center of radiation to the point of calculation, in meters. The factor of 2.56 accounts for the increase in power density due to ground reflection, assuming a reflection coefficient of 1.6 (1.6 x 1.6 = 2.56). The factor of 1.64 is the gain of a half-wave dipole relative to an isotropic radiator. The factor of 100 in the numerator converts to the desired units of power density. This formula has been built into a proprietary program that calculates, at each location on an arbitrary rectangular grid, the total expected power density from any number of individual radiation sources. The program also allows for the description of uneven terrain in the vicinity, to obtain more accurate projections. Methodology Figure 2
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California Statement of Hammett & Edison, Inc., Consulting Engineers The firm of Hammett & Edison, Inc., Consulting Engineers, has been retained on behalf of Verizon Wireless, a personal telecommunications carrier, to evaluate its base station (Site No. 279040 Mosquito Road ) proposed to be located at 1070 Meadow Lane Court in Placerville, California, for compliance with appropriate guidelines limiting sound levels from the installation. Executive Summary Verizon proposes to install a new base station, consisting of equipment cabinets, a back-up generator, and antennas on a tall pole, near the municipal water tank located at 1070 Meadow Lane Court in Placerville. Noise levels from the equipment operations will be below the City s permitted limits. Prevailing Standard The City of Placerville sets forth limits on sound levels in its General Plan. Proposed equipment installations in noise-sensitive areas are restricted by Part II Section VI Subsection 4.a. of the Plan to noise not exceeding 60 dba L dn in outdoor activity areas on the receiving parcel. The composite day-night average L dn that is referenced for this evaluation is a measure that incorporates a 10 dba penalty during nighttime hours (10 pm to 7 am), to reflect typical residential conditions, where noise is more readily heard at night. A noise level expressed in L dn is, by definition, 6.4 dba higher than the continuous equivalent level L eq averaged over the same 24-hour period. Figure 1 attached describes the calculation methodology used to determine applicable noise levels for evaluation against the prevailing standard. conservatively calculated at the property lines of nearby parcels. For the purpose of this study, noise levels are The operation of the back-up power generator during an emergency, when commercial power is unavailable, is considered to be exempt from these limits; however, the generator s operation during periodic, no-load testing is evaluated for compliance. General Facility Requirements Wireless telecommunications facilities ( cell sites ) typically consist of two distinct parts: electronic base transceiver stations ( BTS or cabinets ) that are connected to traditional wired telephone lines, and the antennas that send wireless signals created by the BTS out to be received by individual subscriber units. The BTS are often located outdoors at ground level and are connected to the antennas by coaxial cables. The BTS typically require environmental units to cool the electronics the W8J7.1 Page 1 of 3
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California inside. Such cooling is often integrated into the BTS, although external air conditioning may be installed, especially when the BTS are housed within a larger enclosure. Most cell sites have back-up battery power available, to run the base station for some number of hours in the event of a power outage. Many sites have back-up power generators installed, to run the station during an extended power outage. Site & Facility Description Based upon information provided by Verizon, including zoning drawings by Borges Architectural Group, Inc., dated June 11, 2015, that carrier proposes to install several equipment cabinets and a back-up power generator within a new fenced compound on a new platform to be constructed on the El Dorado Irrigation District property located at 1070 Meadow Lane Court in Placerville. For the purpose of this study, the four equipment cabinets with active cooling fans are assumed to be three CUBE Model PM63912JF1 cabinets cooled by Dantherm 4K BTU air-conditioning units and one CUBE Model PM63912UC1 cabinet cooled by a Dantherm 10K BTU air-conditioning unit. A Generac Model SD030 back-up diesel generator, configured with the manufacturer s Level 2A sound enclosure, is to be installed to the southwest of the cabinets, for emergency use in the event of an extended commercial power outage. The generator is typically operated with no load for a single 15-minute period once a week during daytime hours on a weekday, to maintain its readiness for emergency operation. Several directional panel antennas and a microwave dish antenna are proposed to be located on a tall pole to be sited near the platform; this portion of the base station is passive, generating no noise. The nearest residential property lines are to the west, about 53 feet away, and to the north, about 69 feet away. Study Results The manufacturers provide the following maximum noise levels from their equipment: Maximum L eq Reference Equipment Noise Level Distance Dantherm 10K BTU AC 74 dba 5 feet Dantherm 4K BTU AC 62 dba 5 feet Generac SD030 63.0 dba 23 feet The calculated noise levels for the simultaneous operation of all fans in all four Verizon cabinets are 56.0 and 54.7 dba L dn, at the west and north property lines, respectively, meeting the City s noise limit of 60 dba L dn. On the day on which the generator is tested, these calculated noise levels are 58.1 and 56.1 dba L dn, respectively, also below the City s limit. W8J7.1 Page 2 of 3
Verizon Wireless Proposed Base Station (Site No. 279040 Mosquito Road ) 1070 Meadow Lane Court Placerville, California Conclusion Based on the information and analysis above, it is the undersigned s professional opinion that the operation of the Verizon Wireless base station proposed to be located at 1070 Meadow Lane Court in Placerville, California, will comply with the City s requirements for limiting acoustic noise emission levels. Authorship The undersigned author of this statement is a qualified Professional Engineer, holding California Registration Nos. E-13026 and M-20676, which expire on June 30, 2017. This work has been carried out under his direction, and all statements are true and correct of his own knowledge except, where noted, when data has been supplied by others, which data he believes to be correct. William F. Hammett, P.E. June 30, 2015 707/996-5200 W8J7.1 Page 3 of 3
Noise Level Calculation Methodology Most municipalities and other agencies specify noise limits in units of dba, which is intended to mimic the reduced receptivity of the human ear to Sound Pressure ( L P ) at particularly low or high frequencies. This frequency-sensitive filter shape, shown in the graph to the right as defined in the International Electrotechnical Commission Standard No. 179, the American National Standards Institute Standard No. 5.1, and various other standards, is also incorporated into most calibrated field test equipment for measuring noise levels. 30 dba library 40 dba rural background 50 dba office space 60 dba conversation 70 dba car radio 80 dba traffic corner 90 dba lawnmower The dba units of measure are referenced to a pressure of 20!Pa (micropascals), which is the threshold of normal hearing. Although noise levels vary greatly by location and noise source, representative levels are shown in the box to the left. Manufacturers of many types of equipment, such as air conditioners, generators, and telecommunications devices, often test their products in various configurations to determine the acoustical emissions at certain distances. This data, normally expressed in dba at a known reference distance, can be used to determine the corresponding sound pressure level at any particular distance, such as at a nearby building or property line. The sound pressure drops as the square of the increase in distance, according to the formula: L P = L K + 20 log( D K/D P ), where L P is the sound pressure level at distance D p and L K is the known sound pressure level at distance D K. Individual sound pressure levels at a particular point from several different noise sources cannot be combined directly in units of dba. Rather, the units need to be converted to scalar sound intensity units in order to be added together, then converted back to decibel units, according to the formula: where L T is the total sound pressure level and L L 1, L 2, etc are individual sound pressure levels. T = 10 log (10 L 1/ 10 + 10 L 2/ 10 + ), Certain equipment installations may include the placement of barriers and/or absorptive materials to reduce transmission of noise beyond the site. Noise Reduction Coefficients ( NRC ) are published for many different materials, expressed as unitless power factors, with 0 being perfect reflection and 1 being perfect absorption. Unpainted concrete block, for instance, can have an NRC as high as 0.35. However, a barrier s effectiveness depends on its specific configuration, as well as the materials used and their surface treatment. Methodology Figure 1
Kelly-Moore Log Cabin Brown