What You Should Know When Buying a Central HVAC Unit

Has your central air conditioning unit started to give you signs that it may be near the end of its days? Maybe you’ve noticed some strange sounds, odd smells, or just an overall lack of cool air. The average lifespan of most HVAC systems is an average of 10 to 14 years. While your HVAC unit may still have some life left, you’ll likely need to purchase a new one at some point in the future.

HVAC units are a big-ticket items with a range of features that can make purchasing one feel daunting. Luckily, we’re always here to help with recommendations and installation. Here are a few things to consider if you’re planning to purchase a new HVAC unit.

The Right Size

Homeowners make one common mistake when it comes to choosing an AC unit: they often get one that’s too large – or small – to cool their home efficiently. It would be great if replacing your HVAC unit was as simple as swapping out the old one for an identical-sized unit, but that’s unfortunately not the case.

The best way to choose a unit that will fit your cooling needs is to have one of our technicians come out and perform a load calculation. This will determine the size of the HVAC unit you’ll need to have optimal cooling for your home. The load calculation also helps us determine the amount and size of air ducts that your existing system has and whether they’re working properly.

Energy Efficiency

Buying A Central HVAC Unit

Another important factor to consider is choosing a new unit with the highest possible Seasonal Energy Efficiency Ratio (SEER). This is the measurement of the amount of energy that’s needed to deliver the right amount of cooling. All AC models sold in the U.S. are required to have a SEER of at least 13; a SEER of 14 to 25.5 would be considered a high-efficiency model. Since it gets hot and humid here in the summer and you’ll likely be running your AC a lot, it’s best to choose a unit with the highest SEER you can afford. Keep in mind that all Energy Star-rated units do qualify for a federal income tax credit.

Compressor Type

By far the most important and expensive component of a central HVAC unit is the outdoor unit with the compressor. The compressor is the heart of your system that heats or cools your home through compressing the refrigerant gas.

There are three types of compressors: single-stage, two-stage, and variable capacity.

Single-stage compressors only run on a single, high speed. They turn on when the indoor temperature exceeds the temperature setting on your thermostat, then operate at 100% capacity. Once the temperature has dropped down to the desired setting, it will turn off. Since the unit is working on full blast, it can result in higher electricity bills.

Two-stage (also called dual stage) compressors operate at two speeds: high – 2/3 capacity and low – 1/3 capacity. Two-stage compressors will cycle from high to low depending on your cooling needs. Typically, they run on low, which results in more consistent temperatures in the home as well as lower electric bills.

Variable-capacity compressors work differently than either single or two-stage compressors. Variable-capacity can fluctuate from 1/3 capacity to 100% in 250 increments. They modulate during the day, providing a slow, steady stream of conditioned air. Due to the longer run times, variable capacity compressors can dehumidify your home more effectively in the cooling season. Units with this type of compressor are also easier to add zoning to your home, which can effectively increase your energy savings. As you can see, there are quite a few considerations for when you’re shopping for a new AC unit! If you’re planning to buy a new unit soon, turn to your friendly Home Service Heroes at PECO! We’re happy to help you with recommendations, performing load calculations, and installation. Schedule your appointment today by contacting us at 864-639-2424.