House air conditioning replacement

Here's a really neat video applicable to any A/C.
Just FYI - your's is a 4ton unit according to this link -



Calculating tonnage of your air conditioner

It can handle five tons, or a 60000 btu ac. Tonnage is a measurment for the ac, 1 ton-12000 btus. The ac dose the cooling. the furnace simply blows the air, so if its a good furnace, and sized right, no need to replace it. Simply add the split system to the existing furnace. If you want the tonnage of the ac size, let me know your homes squarefootage, age, condition. Do NOT include the basement in the sq. ft.

Read size of air conditioner you need , each ton of air conditioning will keep cool 400 square.so higher ton yo pick you feel cool.please read below square feet to ton chart.
1 ton on 400 sq. ft.
2 ton on 800 sq. ft.
3 ton on 2000 sq. ft.
5 ton on 2570 sq. ft.

12000 btus = 1 Ton. A simple ballpark method is 600 to 800 Square feet per ton of cooling. Therefore using this simple method I would say that a 2 or 2.5 ton would do just fine.

With that said the best way to determine the actual size is to perform a heat load calculation on the home. The process can be pretty overwhelming if you don't do it every day. You could call a local HVAC company to perform the calculations for you or you can purchase software online for a couple of hundred dollars and do it yourself.

Either way you choose remember that a properly sized air conditioner offers less hot and cold spots in the home and keep the utility bills down.

The Old Rule of Thumb is 400 square feet per ton, but you really need to do a heat load calculation to be safe. A lot of windows on the west or south side of the house will really increase your load and you may need a lot larger unit. Insulation also changes your load so you may be able to cool a larger area. You may be able to get the Heat Load Calculation Form either online or from Johnstone supply. They are on the internet.

If the system is actually doing everything it can, which I do occasionally run into, then it's time to start looking at other factors like the heat loads. Number one problem I run into is either attic insulation or attic ventilation. One thing that really sticks out in your post though is the square footage and tonnage. Now, to be honest, what the square footage is from the home owner to actual living space always varies. Home owners always get the square footage like a realtor, but includes the garage and other unconditioned rooms. What your looking for is the square footage of only the rooms that have a vent. It is 400cfm per ton, 1 cfm per square foot. So if you have a 2.5 ton system, it is capable of doing 1000 square feet of living space. You said 1500 square feet, which would need a 3.5 to 4 ton system. Hope this helps and gets you to cooler days!

Looks like a 3-1/2 ton system or 42,000 Btu's. Rule of thumb is to design a cooling system that can keep up with 15 Btu's per square foot without too much Southern exposure. Not knowing the exact size and location of your windows it is hard to tell if unit is undersized. If south of Conneticut, I would have put in a 4 ton system.

First off - the 'rule of thumb' is 600' per ton of Air Conditioning. In other words your old unit is a 2 ton unit. So - 2 tons x 600' = 1200'. As you can see if you install the 2.5 ton unit - you will be installing a AC that 'could' cool a 1500 sq ft house (2.5 x 600' =1500 sq ft.). Slightly more than what you need; and the 3.5 ton unit is 'way to big,' (3.5 x 600' = 2100 sq ft.).

Note: fyi - many in the AC business will sometimes refer to tonnage in btu's, i.e. 1 ton = 12000 btu - hence a '2 ton unit' can also be referred to as a 24000 btu unit and vice versa.

So... from the above - you can easily see that "2 tons" of Air conditioning is what is required to cool the 'average' home of 1100 sq ft. "roughly speaking."

Note: it is always best to have a professional 'size' your cooling/heating needs.

One of your questions was could you 'mix tonnage?'

The answer is 'usually you don't mix the tonnage of your outside/inside units.' However, professionals sometimes do (mix the tonnage) in certain situations, and installing a 2.5 ton outside unit with an existing 2 ton inside unit is often done, however, there are some 'tech issues' here and - I would "again" recommend that you call a Service Tech to help you with the sizing/mixing of your cooling/heating needs.

hope this has helped

I would have an air conditioning contractor do a heat load calculation and give you and estimate. 3 ton may work if your insulation is good and your windows seal well. 4 ton may be too much and you won't get the humidity removal needed in Florida.

One ton of cooling per 500 square feet of space assuming you have good insulation. Yes, 4 tons for 2000 feet would be accurate.