How to Install Central AC in an Old House – The Right Way!

If you live in an older home and are considering installing an air conditioner, that can turn out to be a massive project. Because we know how stressful major home projects, like installing new central AC and ductwork can be, we’ve come up with a few helpful hints to make sure you avoid costly mistakes like buying the wrong sized unit or overpaying for an AC unit. Keep reading to learn more!

Choose The Right Size Unit

Making sure that your new central AC unit is appropriately sized is one of the most important aspects of replacing your unit or installing a new one. If your new unit is too big for your house, it could cool your house too fast, causing it to short cycle.

This can cause damage to the units compressor and drive up your monthly energy bill. A unit that’s too small, by contrast, will always be running in an attempt to get the whole house cooled. This will have the same result as an oversized unit: higher energy bills. There are a few different ways to calculate the appropriate size unit for your home. The easiest formula is as follows:

(Sqft of home x 30) / 12,000 – 1.0 = Required tonnage of AC unit
For example, a 2,000 sq ft home would require a 4 or 4.5-ton unit. In areas where higher temperatures are common throughout the year, you can adjust the formula by subtracting 0 instead of 1.0.

Ducts Aren’t Always Necessary

If your home was built before 1980, chances are it was not built with a central duct system. In this case, you may be hesitant to install central cooling because of the hefty cost of installing ductwork, not to mention the mess it makes.

Well, good news! You can now have central AC without installing ductwork! Ductless split systems, or “mini-split systems,” consist of multiple fan-coil units that can be distributed throughout your home as desired, connected to an outdoor unit via refrigerant piping.

These units combine the flexibility of room units with the convenience of central AC, and can even be purchased in high-efficiency models, some with SEER ratings as high as 18 or 19.

Average Cost is $3,500 to $4,000

The total cost of your new central air cooling depends on a couple of factors. The first thing to consider is the type of unit you’d like installed, whether traditional or mini-split.

Mini-split systems are more expensive than traditional units, sometimes costing as much as 30% more. Split systems, however, can offer you the benefit of government tax breaks if your unit has a SEER rating of 16 or higher. Packaged air conditioners with a 14 SEER rating or higher also qualify for this break.

The next thing you should consider when looking at the cost of a new unit is that you don’t want to sacrifice quality to save a little money. Make sure that you are purchasing a unit that is the appropriate size for your home, that the air flow from the system is good, that your ducts are in good condition, and that the unit has enough refrigerant to keep the house cool in order to get the best value out of your new unit.