/challenges-projects/project14/controlsystems/b/blog/posts/fresh-air---hvacFresh Air for a building due to Covid-19. I would like to add fresh air to the furnace air return to improve the air quality within a building. I would like to design the system to control CO2 using an incremental approach. Using a Raspber...en-USTelligent Community 12https://community.element14.com/challenges-projects/project14/controlsystems/b/blog/posts/fresh-air---hvacFri, 28 Aug 2020 18:49:14 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:00bb8ce1-d082-48ab-bc5b-655cf9513a27colporteur1<p>MF I don&#39;t wish to dampen the enthusiasm of your project but isn&#39;t what you desire contained in a heat exchanger unit?</p><p>&nbsp;</p><p>The device moves warm air out and heats incoming cool air. It is not only exchanging heat but air as well. Now heat exchangers don&#39;t operate on CO2 levels. They do have a method of being triggered manually that could be connected to gas monitor. </p><img src="https://community.element14.com/aggbug?PostID=9773&AppID=270&AppType=Weblog&ContentType=0" width="1" height="1">https://community.element14.com/challenges-projects/project14/controlsystems/b/blog/posts/fresh-air---hvacFri, 28 Aug 2020 18:31:22 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:00bb8ce1-d082-48ab-bc5b-655cf9513a27mfetting0<p>Given we have two HVAC units for the building, each with an 8&quot;&quot; round duct limited to damper either opened or closed, I will only control damper to either position, eliminating the increment of degree.</p><img src="https://community.element14.com/aggbug?PostID=9773&AppID=270&AppType=Weblog&ContentType=0" width="1" height="1">