so the purpose of this video is to talk about the preferred installation arrangement for a demon of fire and this diagram has over here on this side is a preferred basement which is really about the orientation of the air handler being up flow so that could be in a mechanical room closet in a garage any place where the air flow is up flow or an attic installation which is pretty much just horizontal flow on the left side is the preferred installation which is what we call return to return on the right side these alternatives are for return to supply and so all four are acceptable really it's two styles return to return or return to supply all for all two are acceptable but what's preferred well return to return is preferred and for a couple of different reasons the first thing for return to return is that because the fans inside the air handling unit and the humidifier could potentially operate in series they work easier so there's less a load on the air handler blower and there's less load on the DV to fire blower and the CFM remains constant if anything the pressure between the two fans could enhance each other not fight each other so that's a big part of why return to return is preferred because it's easier on the air handler blower and it's easier on the dehumidifier blower the other thing is when the demon fire discharges air the air tends to be a little bit warmer than the air that entered the humidifier due to the process and so by discharging the warmer air into the returned it's closer in temperature so there's not as much variance on the actual temperature of the air entering the area of the unit and by entering the warmer air into the air handling unit it can be cooled and further dehumidified before it's discharged into the space so that's why that's preferred on the alternative which is supply to return usually that's done with our space restrictions we can't get this required six feet that you have to have between the two branches here you can't get six feet of clearance within a room or space or an addict then you can always find a way to get something tied to the returned and something tied to the supply so that's one of the drivers of why to utilize the returned to supply configuration but the fans can be in conflict that's why there's requirements that say that you have to have air flow that's within a pressure range otherwise if the fan from the system runs at too high of a pressure it'll actually become a conflict with and block the airflow from the diamond fire so the fans are actually pushing against each other in a return to supply configuration which is harder on the each of the blowers for both the air handler and the D you also the air being discharged into the supply is warmer than the return so you're taking cold supplier now you're mixing warm air with it which could sort of have an impact minor but could have an impact on the cooling effect of the air going into the space so we prefer to do the installation where we go from return to return so the air gets sucked up by the humidifier our blower and then redistributed back in at that point the air goes through the normal cycle through the air handling unit through the cooling coil and then off into the space with cold discharge air that's the recommended way it works better and everything works more efficiently that way and that's how I do it at my house as well so any questions let me know but that's how we do it return - return us preferred method return the supply is acceptable but has two disadvantages boom