Straight AC, Heat Pump, and Heat Kit: What Do They Mean?

When it comes to home comfort, HVAC terminology can be confusing. Three common system types homeowners hear about are straight AC, heat pump, and heat kit. In this blog, we’ll explain what each of these systems is, how they work, and why the differences matter to the average homeowner.

What Is a Straight AC System?

Straight AC is a term used to describe an air conditioning system that only cools the home. This type of system uses refrigerant to transfer heat from inside the home to the outside. That’s why the air coming out of the top of an AC unit in the summer should feel warm. If it does not, it may be a sign of a problem—contact us or your local HVAC specialist.

A straight AC system is typically paired with a furnace to handle heating during the winter months. One benefit of a straight AC system is that it has fewer components, which means fewer parts that can fail and, in many cases, a longer system lifespan compared to a heat pump.

The downside to a straight AC system is that it often requires gas service if the home does not already have it. If gas is not available, the home may need electric-based heating, which is generally much more expensive to operate.

What Is a Heat Pump System?

A heat pump is a type of HVAC system that both heats and cools a home using the same outdoor unit. When cooling, a heat pump operates the same way a straight AC system does. The difference is that a heat pump includes a reversing valve, which allows the system to reverse the flow of refrigerant.

By reversing refrigerant flow, the system can pull heat from outside the home and move it inside. Even when outdoor temperatures are around 30 degrees, there is still heat present in the air.

Heat pump performance can vary by region and climate, but in Alabama, heat pumps are able to heat a home efficiently for most of the winter. However, during the coldest times of the year, a heat pump may not be able to keep up on its own—this is where the heat kit comes in.

What Is a Heat Kit?

A heat kit is a supplemental electric heating system installed inside an HVAC air handler. When outdoor temperatures drop too low for the heat pump to heat the home effectively, the thermostat sends a signal to energize the heat kit.

Electrical power flows through metal heating elements known as heat strips. As air passes over these heat strips, it is heated before entering the ductwork. Air leaving the system after passing over the heat strips is typically heated to 90 to 120 degrees.

Heat strips work well in low outdoor temperatures, but they are very inefficient and use a large amount of electricity. This is why heat kits are commonly paired with heat pump systems. The heat pump handles heating during mild and cool days in a much more energy-efficient way, while the heat kit only runs during the coldest days.

Choosing the Right HVAC System

Each of these systems has its own pros and cons and is beneficial in different situations. Straight AC systems, heat pump systems, and heat kits are all options homeowners should consider when installing or replacing an HVAC system.

If you are local to our area and wondering which type of system you have—or the best way to maintain it—use our “Let’s Chat” button to speak with an HVAC technician who can help guide you.