Central air is a good choice, but it’s not the only one you have
The right choice? The question might catch you off guard because there has been only one popular alternative to central air conditioning. Okay, maybe there are two options if you include the decision to skip cooling your home with air conditioning altogether.
Otherwise, the choice is to attempt to cool areas with room air conditioners, or with a central air conditioning system. Thanks to the rapidly growing acceptance of ductless mini split systems in the United States – which are extremely popular around the world – there are now three choices. So, before you go with the standard choice, here’s now to decide if central air conditioning is right for you.
How air conditioning works
According to the U.S. Department of Energy, nearly all air conditioning systems have a lot in common with the refrigerator in your kitchen. They mainly run on electricity, and they use it to transfer heat from the interior of your home or office to the outside environment.
There’s an indoor coil and an outdoor coil. A compressor pump transfers refrigerant liquid between these two coils, which pulls heat out of the indoor air and transfers it to the outside. This refrigerant transforms from liquid to gas, using the process of condensation to remove heat. It may sound like playing with words and definitions, but HVAC professionals will tell you that an air conditioner isn’t really making air cold – it’s removing the heat from the air.
Energy.gov agrees: The two most common types have been room air conditioners that usually are installed in a window to allow for the exchange of air or central air conditioners that use ducting throughout your home or office for the exchange.
The website says that today, there’s also what they call a “compromise” between these two traditional systems. It’s the ductless mini split system, which acts far more like a central air conditioning system – but without the extensive ducting system that must be installed throughout your home or office to accommodate the air exchange.
How they’re packaged
Room air conditioners are what’s known as a packaged unit, meaning that the evaporator coils, condenser, and the compressor are all housed together. It sits in a window.
Central air conditioning systems are considered to be more efficient. Slate Magazine writes that it’s because many window units just aren’t as advanced as their central system counterparts. Central systems can move a large volume of air and remove humidity in a way that window systems can’t.
The website also notes that while central air systems are more efficient than room air conditioners, they can have an energy efficiency loss of up to 30% because of something called “duct losses.” The cold air on its way to rooms throughout your home or office warms up, or it leaks through fittings.
Ductless mini split systems are more like central air conditioning systems, but without the ductwork needed to move air throughout your home or office.
Cooling area size
One of the most important considerations when deciding to go with central air conditioning is determining if it will provide you with the level of environmental control you want. Smart thermostats allow you to have a higher level of temperature control, but most central air conditioning systems have just a single thermostat. This can make it difficult to have uniform temperatures throughout the rooms in your home or office.
While it might make sense to buy an oversized system to compensate, you’ll actually end up making things worse. Central air systems should be sized for efficient operation. If the system is too big, the cooling happens in cycles too short to also dehumidify the air – a crucial component of effective air conditioning. Experts suggest that while it may not be as energy efficient, it’s better to undersize a central air system. Yes, it’s costlier to operate, but less costly than the inefficiency caused by an oversized central air system.
Do you have ducts?
Often, a deciding factor for central air conditioning is the existence of ductwork in your home. You may already have what you need if the home or office has a central heating system. Money Magazine says that a lack of the necessary ductwork in your home can add $4,000 to $5,000 to the overall cost. If you already have the ducts, it may be necessary to upgrade or seal them, which still may add $1,000 to $3,000 to the cost of central air conditioning.
The alternative to expensive ductwork is to install a ductless mini split system. You can take a more specific approach to cooling and heating this way. These systems don’t need ducts. The indoor air handler is connected by a conduit that houses power, refrigerant, and a condensate drain for dehumidification. Each air handling unit maintains the environmental control for a room. You get the benefit of creating a system of units that act like central air conditioning, but with precise control, no ducts, and much better energy efficiency that correlates to drastically lowering operating costs.