Optimizing Air Flow
The objective with home cooling using window units is to get an adequate cooling capacity (unit size in BTU) and getting the air to flow in as much of an unobstructed manner as possible. And where there are obstructions (like walls) we’ll create the air flow direction we want with the use of simple 16-inch electric fans strategically placed in doorways. The idea is to draw the cool air conditioned air into the remote rooms with the fans located in the doorway and you can use multiple fans to “bend” the cool air flow around corners.
To make this all work it starts with picking out the best location for the window air conditioner that will serve the floor. Ideally, you’ll want to pick a window that is in a central hallway which feeds the rooms you want to cool.
If that is not appropriate for your floor plan, then choose a room near the center of the floor. That location will reduce the amount of cool air flow needed. If you can pick a room where the main secondary room you want to cool is across the hall and nearby, then even better. Airflow will want to stay in as much a straight line as possible so don’t expect it to bend around corners easily.
It will more efficiently follow more of a “nudge” in a slight bend through careful placement of the fans.
If you have a situation where you need to force air past more than two doorways or around a sharp bend as I described above, then you may need a second window air conditioner.
Here is another weird trick you can use if you have a forced air furnace with ductwork. Try and have the room air conditioner blow its cold dehumidified air towards a return air grill or register of your furnace heating system. Then turn on the blower fan on your thermostat setting (“fan only”) to move the cool air into the home. The better job you do directing the air to the return air register the better the results.
These tips will not be as efficient or quiet as a whole house central air conditioning system but if you do not have that option available to you, then the above tricks can help get you a cooler home this summer.