Air Conditioner Unit: Vent Open or Closed?? (1 Viewer)

[Micheal]

My Brother has an air conditioner that sits in the window of his apartment. He called me tonight and asked me if the vent should be set to open or closed. I have no idea?

I was thinking that if it is really hot and humid outside that he should set it to closed.

Any ideas?

 

[Philip Hamm]

I believe that is like the recirculated air in your car. Open means you get outside air, closed means you get inside air.

 

[Micheal]

Thanks. I looked it up and it seems that I had the right idea. If you want it to be a cold as possible, keep the vent closed.

(Unless you are using it in during the Winter)

Thanks Philip

 

[Philip_G]

sounds like you got it. On my old unit the vent was a small trap door that sucked air in, but didn't draw ALL the cooled air from outside, just added some fresh air to the output.

 

[Matt Stryker]

Usually the idea setting is half open/half closed for recirc/outside air. This maintains a good balance of new air but also keeps the unit from working too hard.

This was from a friend who used to design HVAC systems for large buildings; they tried to keep their mixing boxes so they would pull half/half. It also works really well in cars, provided you have a mixing control instead of just one button.

 

[ken thompson]

Well, a central unit draws all of its aire from inside and recirculates it. I'd think this would be more efficient for a widow unit as well. The unit would be cooling already cooled air instead of the hot outside air. I believe the vent should be open only if the unit is being used as a fan only and not cooling.

 

[Philip_G]

This was from a friend who used to design HVAC systems for large buildings; they tried to keep their mixing boxes so they would pull half/half.

usually they use air exchangers with air to air heat exchangers in them so they don't loose as much energy though.

 

[Matt Stryker]

usually they use air exchangers with air to air heat exchangers in them so they don't loose as much energy though.

Right...I was just quoting the basic principle. The most efficent setting is usually the recirc only one, but it can make the air get really stale and in some cases unhealthy if you don't introduce fresh air into the system. It probably also depends on how tight or loose the house is in terms of airflow; a lot of times "sick" buildings are ones that don't get enough fresh air through cracks and vents. I had that problem with my basement HT initially. The recirc setting can help a lot if you are trying to reduce the humidity quickly, not just the temperature.

Michael, does the air blow cold when the unit is set to "vent"? It might work like Ken suggested and only exchange air instead of refrigerate it on that setting.

 

[Micheal]

My brother tried it out, it blows colder with the vent closed. He has a separate knob for "fan" & "cool".

He has now found that having the vent closed produces cooler air. (With the other knob set to "cool" of course)

Thanks again guys!