Central air question.

[trof]

OK HVAC people, here's my theory:
If we close off two unused bedrooms and close the HVAC vents in them it'll cost less to cool (or heat) the house.

The air conditioning guy says "Not really", but offered no explanation.
What say you?

[Lilyhoney]

1. I think you are correct in your assumption.

But I am not a HVAC person. I have only tried your theory. :shrug:

[Rising Phoenix]

2. my mom swears by your theory

give it a try, the worst that can happen is your bill stays the same

[In_The_Wind]

3. how many zones do you have

[trof]

7. Just one. One unit outside.

[In_The_Wind]

15. here's the deal from my experience

The thermostat which controls your central air is the area you need to think about. IF you do close rooms you will conserve on the energy usage but the walls between rooms & interior hallways aren't going to be insulated so there will be some heat transference through the common walls of the rooms without air-conditioning. If you close these rooms be sure to ventilate them frequently as the air-conditioner will also act as a dehumidifier so you risk a mold/mildew growth if the humidity builds within those rooms.

if this also controls the heat in your home take care to adjust the call for heat much lower than you would in the winter to avoid having the system fighting with itself


I had a new system installed 2 summers ago and there have been some unpleasant surprises but overall I'm glad it's done.

good luck & enjoy being cool

[OffWithTheirHeads]

4. Yes, you can do it to a certain extent

There has to be a certain amount of airflow across your cooling coil or it will freeze up and not cool your house at all. If you close too many vents, not enough air will pass through. If you notice ice forming on the refrigerant lines on the outdoor unit, youve gone too far.

The cheapest thing you can do to improve performance is to make sure your filter is clean. This is probably the #1 problem I see in the industry. People pay no attention to the filter which results in poor air flow and greater expense.

Also, it's better to have your a/c keep the house somewhat cool (like 78f) during the time your not there and then have it cool the house to a more comfortable setting when you are home, rather than have it try to bring the temp down from say 90 when you get home.

signed
been in the biz for 37 years

[trof]

8. Aha! A pro. Thanks.

[Mutley]

5. That seems to have worked for me in the past.

It didn't make a really huge difference, but it made a difference.

[billyskank]

6. Don't theorize: try it!

It'll either work or it won't, and whaddya got to lose?

[Old_Fart]

9. We closed off our vents one time

It screwed up the lower level in our houses central air conditioning.

The HVAC guys are not earning a dime from your electricity bill. Get a second and a third opinion. Go with the third opinion and don't let a few dollars cost you thousands.

I had to purchase a whole new system and it cost us a couple thousand dollars. :wow:

[trof]

10. We're one level, one zone, one unit.

[Old_Fart]

11. You can close them off

If its one level and you are on a slab then I don't see the harm in closing off the vents.

[trof]

12. I've been doing it far a while.

But haven't taken the time to compare elec bills.
Now I will.

[Old_Fart]

13. When you find out can you post

I would be curious in knowing if it helps or not.

[RedSpartan]

14. I think that'll work.

I never trust what the power co. tells me. A year ago, before the baby came and my wife and I both worked, we would turn off the a/c when we left and turn it on when we got home. "Oh, no, don't do that," said the power co., "that'll cost more than just leaving it on." Our power bill never went over $75. This summer, with the wife home and a/c all day (ok, and a few extra loads of laundry) our last bill was $200. Trust your instincts.

[Misunderestimator]

16. Yes, it will save you money.

I have spoken.