I have a 1 ton central air unit currently, 1500 sq feet. It works OK but struggles on hot days. I might be able to get a 2 ton for dirt cheap, 2002 model used, same brand (york) as I have now. I have a brother in law that could do the remove/replace work. My question is, would I need to replace anything else (blower, etc) to swap out the 1 ton for the 2 ton? Obviously the 'manifold' on top of the furnace where the coil sits would have to be reworked or replaced. Anything else??

Thanks!

You're probably okay with the blower. You might have to change the fan speed, which is just a matter of swapping wires on the circuit board.

Your 1-Ton is undersized for 1500 sq. ft. You should run a minimum 1-Ton per 1000 sq. ft. and, depending on your heat load (where you live, how many windows, orientation to the sun's path, shade trees, insulation, etc.) 2-Ton may be a minimum for your needs. (You can usually tell the tonnage by the model number of either unit (inside and outside). There will most likely be a 12 or 18 or 24, etc. number in the model number. Divide it by 12 to get your tonnage.)

You said in the title of your thread, "replacing the condensor and the coil." Both are coils, the condensor coil being outside, in the same housing as your compressor and your evaporator coil being inside, in your air handler. Two possibilities: One being that you meant "compressor and coil (condensor coil)" and the other meaning that your evaporator coil also needs replacing.

Either way, if you are going for a 2-ton condensing unit (outside), you should go to at least a 2-ton air handler (inside) or you are going to have a very inefficient system, costing way more than it should to cool your house and, it isn't going to cool any better than it has in the past ("struggles on hot days"). Conventional wisdom to increase efficiency is to go 1/2 ton higher on the air handler than the condensor... exactly the opposite of what you are proposing.

Additionally, you should be aware of the SEER rating (Seasonal Energy Efficiency Ratio) of the units you're installing. For just a few extra dollars you can greatly increase the MPG so-to-speak of your system.

There are lots of sites on the web that can educate you before you do the swap (try something like "Air Conditioning Facts" through Google). A little research will go a long way in getting the most bang for your buck.

By the way, that "used unit," was the condensor coil sealed when it was removed from its previous location? If not, it should be completely evacuated before you start pumping any coolant through it.

Sorry, like I said my brother in law is the HVAC guy.

I meant to say both coils I guess, the outdoor condenser and the indoor evaporator that goes in the ducting. I think the furnace is at least a 18,000 btu (1.5 ton?) it might be 24,000. The AC is definitely only a 1 ton unit.

Not sure if the old coils are sealed but I'm sure I can get it purged if need be.

I can pick up this 2 ton unit, both coils, for $250, so it seems like a good deal, is it? Going to talk to my brother in law to get his ideas when he gest some free time.

Thanks for the thoughts... :)






Also, I'm running under the assumption that the evap coil needs to match the condenser, am I wrong? Could I just replace the condenser outside and run on my current evaporator?

The answer to your questions are: No, you are not wrong, the air handler's output should match (or slightly exceed) the condensor's output; and, no, if you're going to increase the output of the condensor unit you should upgrade the evaporator unit as well.

If your brother-in-law is a seasoned "HVAC guy" he should be able to advise you correctly.
The air handler's evaporator's coil should (at least) match the condensor output. If you are gettting an outdoor condensor/compressor unit that is rated at 2-toms and he installs a 2-ton evaporator coil in your air handler, you should be good to go... as long as the fan can push enough air across the evaporator to keep it from freezing up and make it efficient.

My wife talked the guy down to $200. Talked it over with the brother in law, he thinks that my blower will be fine and I should jump on the 2 ton for that price. So I did. Said he has the tools to purge it if need be and everything we'll need to install it. Going to try to get at least the condenser installed Saturday. Said to only not buy it if it appears to be rusted up or otherwise obviously abused. The photos look good so we'll see.

Thanks for the advice.

Aren't you at all concerned how your wife got it down another 50 bucks?

Just a few of things to keep in mind:
1) it's a bigger machine, you will probably have to upgrade the electrical, the wiring and the circuit breaker.
1a) you may have to go with bigger pipes to and from the condenser.
2) is it an r-22 or 410 machine? 410 runs at a higher pressure, make sure your welds are good.
3) do you have enough space for the new evaporator? (the inside unit)

If your brother-in-law is an hvac guy most of this shouldn't be an issue, congrats on your great deal.