Does closing some of the vents on a home with Central A/C damage the condenser?

If a really big house in central Texas has central Air Conditioning and there are a couple of "currently not in use," back bedrooms...is it wise to close the vents in the rooms that don't need to be cooled right now? I think it's a really good idea because it will save on my electricity bill. But my sweet step-mother, (who has tons of common sense and is usually right about almost everything) insists that this is very hard on the A/C condensor and that I might burn up my outside condensor unit.
I don't think so because I can't see any reason why it would bother the condensor in any way but now she's gotten me all nervous.

Can somebody please straighten this delemnia out?

I have been in the heating and air conditioning business for 15 years now and can honestly tell you it could damage your unit. The unit was designed to cool your entire house not just a few rooms. If you do not get enough air flow across your evaporator coil ( unit inside the furnace ) you can very well cause the coil to freeze. If this coil freezes you will put undo stress on your compressor in the condenser unit and it could burn out. So the answer is YES you could damage the unit. Not saying it will but it very well could do so. Besides if you only close the supply ducts and leave the returns open in the rooms you will now be pulling in high air temps to the indoor unit thus making it work even harder to cool the rooms you want cooled... In my opinion you will not be saving much if any money doing this.

You are correct.Just be sure you don't close off the thermostat or the air return.Your compressor is either on or off.If you cool less space then your compressor will run less.Infact in large buildings phneumatic controlled vents and multiple thermostats is how the zones are kept at the same temp.

I am not an A/C repairman but I have turned vents of in my L.R.,hoping to send more cool air to the bedroom, which faces South. I've never had any problems. Can't wait to read all the responses

i do the same thing with no problems.we have a basement which is cool anyway so we block off the vents so no ac is blown into there, i leave the cold air return open to make sure air still curculates , but you can close off any room you like. if you want to stop all air from reaching the rooms take a towel and place it in a plastic bag and stuff it into the vent as long as you vent does not go straight down ,would hate to drop it way down where ya cant get it out

Crimson is right BUT there is one conditional statement in his answer.

That was "IF" you freeze up the coil it "can" do damage. That requires it to be run for a long time very frozen and still is unlikely that you can get it cold enough to run liquid back to the compressor which causes the damage.

I usually tell people they can shut off one room with no problem. If you shut off two then you need to pay a little attention to how it is working.

I have seen people shut down half and then they call me with problems. lol.

You could shut the vents off and after some hours running check the evaporator. If it is getting frosty then you have restricted it too much. And that is losing efficiency, not gaining it, thus costing you. But if not frosting it is fine.

Good Luck.