Common Types of HVAC Systems

A guide featuring the four most common HVAC system types, and the pros and cons of each.

HVAC systems can be intimidating. There are so many different parts, sizes and types – so how do you decide which one is right for your home? Let’s first look at the four common types of HVAC systems:

1. Standard Split Systems

The standard split system, with one component outside and one inside, remains the most popular residential HVAC system today. Split systems can be configured in several ways to address the demands of your climate:

• Furnace and air conditioner: Most systems employ a gas furnace (only 5 percent have an oil furnace). Gas furnaces range in efficiency from 80 percent (better for warm climates) to 98 percent (a more cost-effective choice in very cold climates). The air conditioner’s condensing unit is installed outside. A key component of the system is the evaporator coil, which is typically installed inside the cabinet of the furnace. The evaporator coil captures heat and sends it outside via the refrigerant circulating through copper lines. Air conditioner models range in efficiency too, and the warmer your climate is, the more sense it makes to install an AC with a higher SEER efficiency rating.
• Air handler and heat pump: Heat pump split systems are common in warm regions where freezing temperatures are rare. Instead of an air conditioner for cooling and a furnace for heating, the system uses a heat pump for both functions. A range of efficiency levels are available. A heat pump is almost exactly like an air conditioner except that its operation can be reversed in cold weather. Because the heat pump delivers heat, an air handler with a blower motor is used in place of a furnace.
• Furnace and heat pump: Split systems with two sources of heat are called dual fuel or hybrid heat systems. They are ideal for very cold climates. The heat pump supplies heat in moderate cold. The system automatically switches to the gas furnace when temperatures drop below freezing and heat pumps become ineffective.

Pros and Cons of Split Systems

Split systems offer the greatest range of options. They are the most affordable HVAC system type, especially for replacement systems. The new components can be installed with no or minor modifications to the home’s existing ductwork. Two-stage and modulating split systems optimize indoor climate control. The disadvantages are that traditional split systems require ductwork, so they are impractical where adding ductwork is too costly or impossible.

2. Ductless Split Systems

Ductless split systems (or ductless mini-split systems) consist of an outside air conditioner for cooling only or a heat pump for cooling and heating. Furnaces are not an option in ductless split systems. The indoor component has a fan for dispersing treated air and can be installed on walls, the ceiling or the floor.

Pros and Cons of Ductless Split Systems

Ductless split systems are ideal for a home or office with no existing ductwork. One outside unit can provide treated air to as many as four indoor units, and each unit can be regulated with its own thermostat for precise, zoned climate control. The efficiency of ductless systems ranges from good to excellent, so they reduce energy use and costs.. The disadvantages of ductless split systems are that they aren’t suitable for very cold climates and they don’t offer the spectrum of options you get with standard split systems.

3. Packaged Systems

A packaged system is manufactured with all the major components in one large cabinet. They are most popular in homes without basements. Packaged units are always installed outdoors. All packaged systems contain a blower to force treated air into the home and draw untreated air into the system. The method of treating the air varies with the type of packaged unit:

• Gas/electric: A gas furnace and an air conditioner.
• Heat pump: One unit providing both heating and cooling.
• Hybrid: A heat pump for most of the heating and all the cooling, and a gas furnace for heating when temperatures are below freezing.

Pros and Cons of Packaged Systems

Packaged systems are only used when traditional split systems are not an option. The advantage is that they don’t create as much noise inside the home, since the mechanical components are outside. The disadvantages are that package systems don’t offer as many options as standard and ductless split systems, and they are far less efficient. Since all the components are outdoors in the elements, they tend to wear out faster than other HVAC systems.

4. Geothermal HVAC Systems

Geothermal systems use the stable temperatures of the earth to facilitate heating and cooling. Water, often containing refrigerant, is circulated through pipes installed in water or the ground to collect or shed heat. The constantly moderate temperatures of the ground facilitate efficient dumping of heat in summer and collecting of heat in winter.

Pros and Cons of Geothermal Systems

Geothermal HVAC systems offer efficiency levels up to four times that of traditional systems. The reductions in energy use and cost are significant. The main concern about geothermal HVAC systems is their price, which can range from two to five times that of other systems.

Which is the Best HVAC System for Your Home or Office?

It is hard to beat the value of a traditional split system in a new or existing home, especially in the first decade. A ductless mini-split system is a cost-effective alternative, though, especially in additions or when the garage or basement is being converted to living space. Package systems should only be considered when a split system isn’t an option. While the cost of the technology is coming down, geothermal HVAC systems are still quite costly compared to traditional and ductless systems. If a geothermal system is in the budget and you plan to stay in your home for ten years or more, then it may be worth considering.

Before you decide what type of HVAC system is right for your home, talk to a certified HVAC technician. At Richmond’s Air, we want to help you choose the best system to meet your needs. If you live in the metro-Houston area, contact us today.