HVAC - AIR HEAT RECOVERY - SILICA WHEEL

thingiverse

AIR HEAT RECOVERY WHEEL WITH HUMIDITY CONTROL The unit connects to the central AC, collecting oxygen-depleted air from bathrooms and kitchens, and bringing fresh air into rooms. An Arduino-controlled motor (Nema 17) spins the Heat Exchange Wheel (filled with Moisture Absorbent - Silica gel). The fresh air and evacuated air pass through the heat recovery unit. In the Unit Drum, heat/moisture exchange occurs: When hot air from outside enters one side, and cool air - room temperature - oxygen-depleted (cooled by an AC unit) enters the other side, the fresh air cools down using the chill of the evacuated air. The difference between a classic heat exchanger (Partition Plates) and this HVAC is that it controls humidity during heat transfer. In the example above, hot fresh air loses moisture and transfers it to the evacuated stream of air. Same principle applies in winter: cold air warms up by the warm air being evacuated. Drum speed is low, 15-90 rev/min; a relation between temperature/humidity exchange and speed can be calculated and developed based on system performance and user needs. Strongly recommend using HEPA filters for all intake connections to protect silica gel filters. See the HEPA filter adapter: https://www.thingiverse.com/thing:4092032 For more info, see: https://en.wikipedia.org/wiki/Thermal_wheel If desired to increase humidity filtration percent, transforming the Heat Recovery Unit into an Air Dehumidifier, accelerate regeneration of Silica gel by flushing the Heat Exchange Wheel with a stream of hot air. See: https://www.researchgate.net/publication/296481064_Effect_of_Regenaration_Air_Temperature_on_Desiccant_Wheel_Performance Components used: * M14 Bolt Hex 130 / nut / washer X2 - 4 units * M5 Bolt Hex Drive Flat Head 100 / nut - 18 units * M5 Bolt Hex Drive Flat Head 50 / nut / washer - 6 units * M5 Bolt Hex 50 / nut / washer- 6 units * M4 Bolt Hex 60 / nut - 2 units * M4 Bolt Hex Drive Flat Head 30 / nut - 6 units * M4 Bolt Hex Drive Flat Head 25 / nut - 6 units * M4 Bolt Hex Drive Flat Head 18 / nut / washer - 32 + 4 units * See McMaster: https://www.mcmaster.com/ Belt used: Belt 2GT 6mm From 228mm 114T to - 302mm 151T closed loop - 1 unit Or use the GT2 140T 6mm Belt supplied. Bearings used: Ball Bearing Axial/Radial 30x72x20.75 - 2 units See Rulmentika: https://rulmentika.ro/rulment-30306-mbf.html Oil Seal used: Oil Seal 30X40X7 - 1 unit See Rulmentika: https://rulmentika.ro/simering-30x40x7-tc.html Motor used: 17 Nema Steper Motor + 2gt 20 tooth gear - 1 unit Pulleys used: 50 tooth 2GT timing pulley - 1 unit See RobotDigg: https://www.robotdigg.com/product/1626/50-tooth-2GT-timing-pulley Silica-Gel without humidity marker!!! See Silicagel.ro: https://www.silicagel.ro/ UPGRADE: In case you do not have a GT2 Pulley for this project, see the new GT2 Pulley 50T and required components. Also, see the new GT2 Pulley 76T and required components. Design printed without support... mostly... except for parts needing support.