Abstract: Example embodiments of the present disclosure relate to improved HVAC devices and kits for HVAC devices that improve the sound attenuation associated with the device, particularly low-frequency noise. An example embodiment includes an improved furnace including a housing with a combustion air chamber, a heat exchanger chamber, and a circulation blower chamber, wherein the combustion air chamber comprises a burner assembly and a combustion air fan, the furnace also includes a sound attenuation layer including a first acoustic metamaterial layer coupled to the combustion air chamber and tuned to attenuate sound for a first frequency band, one or more housing openings fluidly connecting the combustion air chamber to an environment outside the housing, wherein the sound attenuation layer includes a discontinuous section that aligns with one or more of the housing openings.

Abstract: A source application reads a body of data in data block sized units and calculates a checksum value for each data block before sending the data block, the calculated checksum value and the identifier. Upon receipt, a destination application independently calculates a checksum value for each received data block and compares the two checksums. Non-matching checksums indicate a network-induced error in the data block. Identifiers for the erroneous data blocks are transmitted to the source application after all of the data blocks have been initially transmitted. The source application thereafter resends only those data blocks identified. The destination application repeats the process of comparing checksums and transmitting identifiers to the source application until all of the data blocks of the body of data have been correctly received, and then uses the data blocks to recreate the body of data.

Abstract: A source application reads a body of data in data block sized units and calculates a checksum value for each data block before sending the data block, the calculated checksum value and the identifier. Upon receipt, a destination application independently calculates a checksum value for each received data block and compares the two checksums. Non-matching checksums indicate a network-induced error in the data block. Identifiers for the erroneous data blocks are transmitted to the source application after all of the data blocks have been initially transmitted. The source application thereafter resends only those data blocks identified. The destination application repeats the process of comparing checksums and transmitting identifiers to the source application until all of the data blocks of the body of data have been correctly received, and then uses the data blocks to recreate the body of data.