Here's the deal. My house is 1500 sq ft (heated) In Jan of this yr I had
the outside unit of my heatpump replaced. They replaced it with a 2 1/2
ton unit. (I just discovered this 3 days ago) Well from what I've been
told in this group (and after several phone calls to different AC
companies) it should have been a 3 ton unit.

The unit had been working fine until a month ago when my girlfriend
moved in and we opened up a 225 sq ft rm that wasn't being used, NOW the
unit will not cool the house.

I looked at my paper work and it says that the unit was "sized" by sq
ft. I called the company yesterday and told them what was going on and
i was told that they replaced the unit with the same size unit that was
there.

Now that's pretty stupid since the house was built in '84 with a 2 1/2
ton unit and has since had a 225 sq ft room added on.

The guy tells me that it wouldn't matter if he had installed a 3 ton
unit because the air handler is only a 2 1/2 ton unit and it wouldn't
matter as far as cooling is concerned.

My reasoning is that THEY should have installed a 3 ton unit just
because of the sq ft of the house, regardless of what size the old unit
was....I even told the installer that my next step was to get a new air
handler because it was about to go. Wh

Now I'm stuck between a rock and a hard place and don't know what to do,
so here's my question. If I end up having to keep the 2 1/2 ton outside
unit, can I install a 3 ton air handler and will it keep a 1500 sq ft
house cool?

My only other option would be to install a window unit in the addition
and I really don't want to do that.

Thoughts-suggestions?