Unit Size

[ransdell]

Am replacing a 3 ton ac. Have gotten 3 estimates with three differing recommendations on tonnage - 2.5 T, 3 T , and 'you need a 2.5 ton but a 3 ton is ok'. No load calculation has been done. Will a 3 ton result in problems associated with an oversized unit or can I get the 3 ton and still get good dehumidification and no short cycling problems? The Trane unit I want comes in a 3 ton but not a 2.5 ton. (I'm locked into Trane so moving to another brand is not an option. I can only move to another Trane model.)

[lonnirat]

You would be smart to have a load calculation done. Why are you "locked into" Trane? Your comfort will depend on how oversized a three ton may be. The only way to know is a load calc.

[beenthere]

Since no load calc was done, maybe what your house needs is 2.25 ton, so 2.5 would be ok, but 3 ton might not dehumidify enough for you to be comfortable.

In other words, have a load calc done, click on the bulls eye, and you can do it yourself.

[dash]

A load calculation is the best way to decide,but if you don't get that done follow this;

If you have lived in the home,thru HOT summer(s),and it kept you comfortable,then you don't need a larger system.If it doin't run a lot on hot days it may be too large.

If you need a larger system ,the duct system is likely too small to handle it,you need a real Pro,to tell you.That should include checking the External Static Pressure,so ask about it.

[dan sw fl]

Originally posted by ransdell
... and 'you need a 2.5 ton but a 3 ton is ok'.
The Trane unit I want comes in a 3 ton but not a 2.5 ton.

If your house is < ~1700 Square feet with < ~ 250 Square feet of glass ( no location/state given), the 2.5-ton should likely be selected.

You may wish to try review the XL15i model which is now available and may meet your budget.

http://www.trane.com/Residential/Pro...ers/XL15i.aspx

XL16i with 2-stage compressor and Variable Speed Air Handler 4TEE3F037 ( or similar) may suit you also.

http://www.trane.com/Residential/Pro...ableSpeed.aspx

racingdanr11@comcast.net if you wish a more specific review

[airconman]

the XL16i doesn't come in 2 1/2 ton.

[Gunnery Sergeant Hartman]

Originally posted by airconman
the XL16i doesn't come in 2 1/2 ton.

It doesn't, but with the correct coil match you may be able to get it to perform closer to a 2 1/2..
Its all in your product data!

[dgk]

1st we are talking about 4,000 to 5,000 btu's of additional cooling. If you aren't going to do a load calc (which your contractor should do on every sales call) and humidity levels in your area are high. Consider a 2.5 ton with a variable speed indoor unit. This will give you a little higher BTU rating and remove more moisture as the fan speed starts off at a much slower speed (each time it cycles on) and pulls more moisture because of operating with a colder coil. Less sensible heat is initially removed and thus greater indoor comfort.

Mfg's have charts that show what their equipment can do both sensible and latent at a given indoor temp.

[tinknocker service tech]

should have a load done to know for sure what you need
any true contractor should not have a problem doing one
with out a load done
since you have a three ton unit in now and are replacing it with a new one with out a load man-j done and it has praformed well over the years then but the same back
man-j may show it is the correct size and may show you need a smaller one this is why it is so important to do.
guessing is not the proper way to size an ac system properly. in jersey you will need a manual-J IN ORDER TO RECIEVE A REBATE with out it no rebate
so tell your contractors you want it done so you know you have the correct size unit installed

[chillbilly]

Do things right.Stop the guesswork and get the load done.
A load calculation not only should be done, in some states it must be done.
Unfortunately, many localities do not require the load calc when a replacement job is performed.
Then you can have someone check duct sizing.
Then, equipment sizing.
Anything less is unacceptable.

[rayr]

[QUOTE]Originally posted by dan sw fl
[B]

Originally posted by ransdell
... and 'you need a 2.5 ton but a 3 ton is ok'.
The Trane unit I want comes in a 3 ton but not a 2.5 ton.

If your house is < ~1700 Square feet with < ~ 250 Square feet of glass ( no location/state given), the 2.5-ton should likely be selected.

You may wish to try review the XL15i model which is now available and may meet your budget.

Wayyyyyyy to funny. How do u come by this when you dont even know what the outdoor or indoor design temps are??????

[CB24]

A proper manual J heat load calculation is the only way to really know the size unit you need. If a load calc is not done your only guessing.