RF Abatement of a Class A Office Space
RF Abatement – Summary
RF Issues: Cell Phone Antennae-sourced RF Radiation on Neighboring Rooftop
Problems in Detail: Client’s Class A downtown San Francisco office space was being strongly affected by three moderately large cell antennae directly squarely at the office. They were mounted on a neighboring roof, roughly 100 feet away as measured on Google Earth. The mostly glass siding of the Class A office space offered no shielding against the RF radiation from such large cell antennae at such a close distance. While the client had not noted health problems for any office workers in particular, they had noted that their phone lines and networking lines had extremely high levels of static, making their phone systems almost unusable. Their Wifi networking range was also greatly diminished, likely due to interference.
Mapping the RF radiation strength of the rooms of the Class A office space yielded:
Nearly all the rooms on the side facing the neighboring rooftop’s cell antennae were well in excess of 10,000 uW/m2. Bear in mind, that various health related groups consider RF radiation power density levels over 1000 uW/m2 are of high concern.
Other factors to consider: There appears to be an anti-shatter film already on the building’s glass. The office also has a high air conditioning bill.
RF Abatement Project Management:
- Various window films were researched categorized for acceptability for this application. The window film had to provide security and anti-shatter qualities with a low heat gain coefficient and, above all, RF-shielding capabilities. Research performed yielded a window film that provided all of these qualities for 60% less cost than traditional RF-shielding window films.
- Window film application professionals were invited to bid on the project and the quality vs cost decisions were showcased to the client.
- The window film application professional removed all traces of the old window film and applied the new RF-shielding window film.
- Shortly after the window film was applied, RF radiation levels were verified to have diminished.
RF Abatement Immediate Results after Implementation:
The class A office space personnel had reported that the phone line static was greatly reduced to barely noticeable when listening with an intent ear for the static. How did this quantify? Following are the current values that the RF radiation power density levels.
|Before installation of RF-shielding window film||After installation of RF-shielding window film||Percentage Reduction|
|Rooms facing the cell antennae||31,000 microWatts per meter^2 (uW/m2)||990 uW/m2||96.8%|
|38,000 uW/m2||1850 uW/m2||95.1%|
|Not taken||1140 uW/m2||—|
|45,000 uW/m2||2610 uW/m2||94.2%|
|59,000 uW/m2||2870 uW/m2||95.1%|
|15,530 uW/m2||1080 uW/m2||93%|
|15,810 uW/m2||1210 uW/m2||92.3%|
|11,720 uW/m2||720 uW/m2||93.9%|
|4960 uW/m2||450 uW/m2||90.9%|
As is shown above, the reduction due to the RF-shielding window film was very effective. The minimum reduction experienced was 90.9%
and the average reduction was 93.9%. While it is possible to reduce the RF radiation power density further through other means, the main objective of this RF mitigation has been met. The high RF radiation power density that was affecting the phone lines and Wifi networking was reduced to much more manageable levels, eliminating the RF interference (static) on the phone lines and improving Wifi networking functionality.
By: Cameron Freres, Environmental Inspector, EMF Consultant & Building Biologist Environmental Consultant
BPI BA, BBEC, EMRS, CDPH LA