Question about air conditioning.

[Stuart G]

Three bedrooms on 2nd floor. I spend most time in bedrooms A and B....almost no time in C

Would air flow be greater if I opened up the vent in bedroom C, or keep that vent closed. I have been told, the faster the air flow through the house, the faster the air gets cooled. The faster it gets cooled, the cooler the other rooms will be no matter what rooms are getting flow. Usually, I keep that room closed and very warm, does not get flow from AC. Is that the best way to go?

[hollysmom]

1. I don'[t know that answer to this

I have an attic fan and find if I keep the windows open in the rooms I use I get the most effective use of the fan and don't need air conditioning except maybe 3 days a year, even then I can live without if, but if I have company they can't deal with heat.

[OffWithTheirHeads]

2. Keep C closed. No point cooling a room you don't use.

That's based on 43 years in the industry.

edited to add; if theroy B were correct, you might as well cool your garage too. Makes no sense.

[Stuart G]

4. Thank You for your time and effort in answering

Stuart G...

[IrishAyes]

7. The folks in this group are so helpful in many ways. I appreciate them too.

[Curmudgeoness]

3. I have heard both cool it and close it off as the right way to do it.

The "cool it" crowd say that the warm walls and air from under the doors will make the A/C would harder to try to cool the area around that room. The "close it" crowd will say don't waste the A/C on a room you are not using.

I have never heard the faster air flow through the house makes it cooler. If that were true, it would seem to be best to close everything but one or two rooms off to make it flow really fast. I do know that in the office I work in, the installed all new ductwork and vents, and the vents cannot be closed off, only opened full blast or could close about halfway. I wanted a vent that could be completely closed off because I hate A/C blowing on me, and they said that the A/C would not work as well if they had vents that would close. I don't know why.

If you aren't sure, try testing it. See if opening the vent in there makes the A/C work longer, or your bills to go higher, or if keeping it closed off is better. Since there is contradictory opinions out there, that is the best we can do.

[Stuart G]

5. Thank You for your time and effort in answering...Stuart

[Kaleva]

6. You can increase volume to used rooms by closing off unused rooms.

This will cool your used rooms quicker and the A/C ought to run less.

As mentioned by another member, it doesn't do much good to cool or heat unused rooms.

[hunter]

8. When my wife and I had little money and lived in a place that got too hot and humid to sleep in...

... we put a small super-efficient air conditioner in our bedroom window.

There was no way we could afford to cool the entire house.

With no more cooling than that the rest of the house was still tolerable because the little unit removed so much water from the air.

85^oF or more isn't so bad if the humidity is lowered.

It helped also that the house was almost entirely shaded by deciduous trees.

[MADem]

9. We just cool one room this year.

Can't stand the heat? Go in the TV room. There are couches in there to flake out on, too.

It's certainly cheaper than trying to cool off several rooms (our house is too old for "whole house" a/c). We've had a few miserable days, but the one room is comfortable.

[NYC_SKP]

10. I hate to have to disagree with some of the advice you are getting. There is no simple answer.

In the end, it depends on your home, its age, the system, ductwork, etc.

It could very well be a bad thing to close ducts. In my town the utility company gives classes to contractors and educational tours to customers.

I was told not to shut off rooms because it can mess with the balance of pressures and have negative impacts. They had a plexiglass model house to with fans and smoke to illustrated the concepts.

You might check with your utility company to see if they'll come out to visit your house.

If you have central air conditioning, do not close vents in unused rooms. This could increase pressure and cause leaks in your ducts. This does not apply to homes or apartments with window units, where closing off unused rooms will reduce cooling costs and increase comfort.

http://www.garlandpower-light.org/utilconstips.html

[Kaleva]

11. It probably would be best to have an expert check out the house.

As you stated, there are a number of variables that need to be considered and there really is no way to provide a good answer here without being on site and doing an ACCA ((Air Conditioning Contractors of America) Manual J and Manual D.

However, the OP is asking about closing off 1 bedroom in a 3 bedroom home and I don't believe that would have any negative impact on the system.