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Should You Consider An Undersized Air Conditioner For Humid Climates?

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When you purchase a new air conditioner, your installer will perform a calculation known as a "Manual J" to estimate the cooling load for your home. This calculation helps your installer determine the tonnage required for your new system, ensuring reliable cooling that doesn't waste energy or overstress your equipment.

In most cases, installing an air conditioner that's as perfectly sized for your home as possible is crucial. A system that's too small will struggle to keep up with the cooling load, while one that's too large will often short cycle and create uncomfortable temperature swings. However, there are some situations where you may want to consider downsizing from the recommended system tonnage.

How Does Your AC Affect Your Home's Humidity?

You probably already know that air conditioners serve a dual role as dehumidifiers, but do you know how this process works? While your home's air conditioner is running, the air near the condenser will cool, causing moisture to condense onto the coils and drain away. Unfortunately, your system can only dehumidify while it's running.

A typical home air conditioner is not a particularly smart system. In fact, your air conditioner does very little decision-making, instead relying on the thermostat to request cooling. Since your thermostat will only request cooling when the temperature is above your setpoint, a system that reaches your target temperature too soon may fail to dehumidify the air in your home effectively.

This limitation can lead to a frustrating choice: turn your thermostat lower and endure cold interior temperatures (and wasted energy) or leave your thermostat alone and deal with higher indoor humidity. Fortunately, there are a few alternatives to help improve the overall comfort level in your home.

What Can You Do About Humidity Control?

The simplest and cheapest option to deal with humid climates is to choose a slightly undersized system. This approach has some drawbacks since your system will take longer to cool your home, but it will also help better control humidity. Undersizing too far will stress your system, so always work with your installer to choose an appropriate unit for your needs.

Another option is to install an appropriately-sized system along with a whole-home dehumidifier. Installing a dehumidifier while replacing your old air conditioning system may help save on labor costs since your installer will already be working with the ductwork in your home. This approach allows you to maintain cooling power while keeping your home dry.

Finally, an air conditioner with a variable-speed compressor may be another option. Variable-speed systems can run in long cycles at low speeds, allowing them to continuously dehumidify your home without drastically lowering the temperature. Although more expensive, these systems can be an excellent option to control humidity without using an undersized air conditioner. 

For more info about air conditioning services, contact a local company.