Detailed answer regarding Ceiling Fan Direction. During the summer, you want the air blowing directly on you so you will feel cooler from the wind chill effect (which is how fans cool you off). So stand under the fan and turn it up on high speed.
NRR STANDS FOR NOISE REDUCTION RATING. NRR (noise reduction rating) is a single number rating method which describes a hearing protection device (HPD) based on how much the overall noise level is reduced by the HPD. Most noise measurements in the industry are derived from the A-weighting scale.
The STC rating is a lab test that does not take into consideration weak points, penetrations, or flanking paths. Acoustical wall treatments with a high NRC can stop sound from reflecting back into the space and lowering the noise level within the space.echnical terms like Noise Reduction Coefficient (NRC) and Sound Transmission Class (STC) can be somewhat confusing. While one measures the build-up of noise within a space, the other measures the sound transmission between spaces.