Central Air for Mobile Homes and Manufactured Housing

Packaged Units vs. Split Systems

Packaged units are the standard choice for manufactured homes. A packaged unit houses the condenser, compressor, evaporator coil, and blower in a single cabinet that sits on a concrete pad beside the home. Conditioned air enters and exits through two large ducts that connect through an opening in the floor or wall of the home. Because all components are in one unit, there is no indoor equipment to install, no refrigerant lines running through the home, and no indoor space consumed by an air handler.

Packaged units for manufactured homes cost $2,500 to $5,500 for the equipment and $800 to $2,500 for installation. They are available in capacities from 2 to 5 tons and efficiency ratings from 14 to 18 SEER2. Most manufactured home dealers and HVAC contractors who specialize in mobile homes stock packaged units and can complete installation in one day. The simplicity of the single-unit design means fewer potential failure points and easier maintenance since all components are accessible in one location.

Split systems, with a separate outdoor condenser and indoor air handler or furnace, are also an option but less common in manufactured homes. The indoor component requires space inside the home, typically in a utility closet, and refrigerant lines must be run between the indoor and outdoor units. Split systems offer a wider range of efficiency options (up to 24+ SEER2) and can be quieter indoors because the compressor noise stays outside. However, installation is more complex and costly, running $4,000 to $8,000 total, and not all HVAC contractors are experienced with split system installations in manufactured home construction.

Sizing for Manufactured Homes

Manufactured homes typically require less cooling tonnage per square foot than site-built homes because they are single-story with relatively low ceilings (7 to 8 feet). However, they also tend to have less insulation, more air leakage, and thinner walls and roof assemblies that allow more heat transfer. These factors partially offset the smaller volume advantage, making proper load calculation essential.

As a rough guideline: a single-wide home of 800 to 1,000 square feet typically needs a 2 to 2.5 ton system, a double-wide of 1,200 to 1,600 square feet needs 2.5 to 3.5 tons, and a larger manufactured home of 1,800 to 2,400 square feet needs 3.5 to 5 tons. These ranges assume average insulation. Homes with upgraded insulation packages (common in northern-market manufactured homes) may need one-half ton less, while homes with minimal insulation in hot climates may need one-half ton more.

Oversizing is particularly problematic in manufactured homes because the smaller volume means an oversized system cools the space extremely fast, short-cycling before removing adequate humidity. Short cycling also increases wear on the compressor and raises energy consumption. A system that is one-half ton too large for a manufactured home creates more noticeable comfort problems than the same oversizing would in a larger site-built home.

Ductwork in Manufactured Homes

Most manufactured homes have a belly duct system, a single large rectangular or round duct that runs the length of the home underneath the floor, enclosed within the belly board (the bottom covering of the home). Supply branches extend upward from this main duct to floor registers in each room. This underfloor duct system was installed at the factory and is an integral part of the home structure.

The condition of the existing ductwork significantly affects cooling performance. Belly ducts in older manufactured homes commonly have disconnected joints, torn insulation, pest damage, and air leaks that waste 20 to 40 percent of the cooled air before it reaches the living space. Inspecting and repairing the belly duct system before or during AC installation is critical. Duct repair costs $500 to $2,000 depending on the extent of damage and accessibility.

Double-wide manufactured homes have two separate duct systems, one in each half, connected by a crossover duct where the two halves meet. The crossover duct is exposed under the home at the marriage line and is vulnerable to damage, disconnection, and insulation deterioration. A damaged or disconnected crossover duct means one half of the home receives little or no conditioned air. Replacing the crossover duct costs $200 to $600 and is one of the most common and impactful repairs for double-wide cooling performance.

HUD Code and Installation Requirements

Manufactured homes built after 1976 are constructed to the HUD Manufactured Home Construction and Safety Standards (commonly called the HUD code) rather than local building codes. This affects AC installation in several ways. The roof structure may have specific load limits that affect whether rooftop equipment can be used. Electrical connections must meet HUD specifications, which differ from standard residential wiring codes in some respects. Any modifications to the home structure, including cutting new duct openings or mounting equipment, must maintain the structural integrity required by HUD standards.

Some local jurisdictions require permits for manufactured home AC installation and some do not. The requirements vary by state, county, and municipality. Checking with your local building department before installation ensures compliance and avoids potential issues with home insurance or future sale. Even where permits are not required, hiring a licensed HVAC contractor ensures the work meets professional standards and is covered by the contractor warranty and insurance.

Common Problems in Manufactured Home Cooling

Inadequate return air is the most common performance problem. Many manufactured homes have only one or two return air grilles, which restricts airflow back to the system and forces the blower to work harder. Adding return air paths, either through additional return grilles or through transfer grilles in interior doors, improves airflow balance and system efficiency. The improvement from adding adequate return air can be dramatic, sometimes reducing hot spots by 5 to 8 degrees.

Roof and ceiling heat gain is disproportionately high in manufactured homes because the roof assembly is typically thinner and less insulated than in site-built construction. Adding insulation above the ceiling (if accessible) or applying a reflective roof coating to the exterior roof surface can reduce cooling loads by 10 to 20 percent. Reflective coatings cost $500 to $1,500 for a typical manufactured home roof and pay for themselves in energy savings within two to four years in hot climates.

Window quality varies widely in manufactured homes. Homes with single-pane windows or low-quality double-pane windows gain significant heat through the glass. Replacing windows is expensive ($3,000 to $8,000), but applying reflective window film ($100 to $300 for a whole home) reduces solar heat gain by 30 to 50 percent and is one of the highest-return investments for reducing cooling costs in manufactured housing.