HVAC Systems for Texas Manufactured and Mobile Homes

Manufactured and mobile homes in Texas operate under a distinct set of structural, regulatory, and climate constraints that separate them from site-built residential construction. HVAC systems serving these structures must conform to federal HUD standards, Texas state licensing requirements administered by the Texas Department of Licensing and Regulation (TDLR), and the thermal demands imposed by Texas's five distinct climate zones. This page describes how those requirements intersect, how conditioning systems are classified for this housing type, and where permitting and inspection obligations fall.

Definition and scope

Manufactured homes are factory-built housing units constructed to the federal Manufactured Home Construction and Safety Standards (HUD Code), codified at 24 CFR Part 3280. Mobile homes, colloquially used interchangeably, technically refer to units built before the HUD Code took effect on June 15, 1976. The distinction carries regulatory consequences: pre-HUD units are not governed by 24 CFR Part 3280 and may present different mechanical system challenges.

In Texas, manufactured housing oversight falls to the Texas Department of Housing and Community Affairs (TDHCA) — Manufactured Housing Division. HVAC contractors working on these structures must hold active licenses through TDLR under Texas Occupations Code Chapter 1302, which governs Air Conditioning and Refrigeration Contractors.

Scope of this page: Coverage applies to manufactured and mobile homes located within Texas and subject to Texas state jurisdiction. Federal reservation land, commercial park-model RVs classified under ANSI A119.5, and site-built modular homes governed solely by the International Residential Code fall outside this scope. Interstate transport of units in progress is not covered here.

How it works

HVAC systems for manufactured homes differ from site-built equivalents in three structural respects: duct routing, unit sizing constraints, and air handler placement.

Duct routing in manufactured homes typically runs through a belly-board cavity beneath the floor or through interior wall cavities, rather than through a conventional attic plenum. Belly ducts are sealed within the home's insulation envelope, making them vulnerable to puncture during repositioning or skirting installation. The HUD Code at 24 CFR §3280.715 specifies duct construction, insulation, and leakage standards for factory-installed systems.

Package units are the predominant equipment type in manufactured home applications. A package unit consolidates the compressor, condenser, evaporator, and air handler into a single outdoor cabinet that connects directly to the home's duct system through a wall penetration. This configuration avoids the need for a separate indoor air handler, which matters in homes where interior mechanical space is limited. Package unit configurations used across Texas are discussed in detail in a dedicated section of this resource.

Ductless mini-split systems represent an alternative where the original belly duct system has failed or where room-by-room conditioning is preferred. These systems require no duct network; a wall-mounted indoor air handler connects via refrigerant lines to an outdoor condenser. Ductless mini-split systems in Texas are increasingly used in retrofit scenarios where duct repair costs exceed equipment replacement costs.

Sizing follows ACCA Manual J load calculation methodology regardless of housing type. Texas's climate zone spread — from Zone 2 along the Gulf Coast to Zone 3 inland — means a 1,200-square-foot manufactured home in Corpus Christi and an equivalent unit in Amarillo may require substantially different equipment capacities. HVAC sizing for Texas homes addresses the load calculation framework applicable to both site-built and factory-built structures.

Common scenarios

Manufactured home HVAC work in Texas falls into four recurring situations:

Original package unit replacement — The factory-installed unit has reached end of service life (typically 12–18 years for package units operating under Texas cooling loads). Replacement requires matching the existing duct connection dimensions and confirming the electrical service panel capacity. TDLR licensure is mandatory for the installing contractor.
Belly duct repair after damage — Rodent intrusion, repositioning damage, or moisture infiltration can breach the belly-board enclosure. Repair requires accessing the underside cavity, which may involve removing skirting and temporarily supporting the home frame. Repaired duct sections must meet the original HUD Code insulation R-value requirements for the applicable climate zone.
Conversion from gas to electric — Manufactured homes originally equipped with gas furnace-and-AC combinations may be converted to all-electric heat pump systems. This conversion requires evaluation of the home's electrical service capacity (most manufactured homes carry a 100-amp or 200-amp service) and may trigger a TDHCA permit for alterations to the home's mechanical systems.
Installation in a new park or on private land — When a manufactured home is placed for the first time in Texas, the setup permit issued by TDHCA covers mechanical connections. HVAC contractors connecting equipment at setup must coordinate with the installation crew and the TDHCA-licensed installer of record.

Dallas HVAC Authority covers the manufactured and mobile home HVAC service landscape specifically within the Dallas metropolitan area, including contractor listings, equipment service providers, and local permit office contacts relevant to Dallas County installations. For the North Texas region, where slab-on-grade and pier-and-beam manufactured home placements are both common, this resource provides locally grounded reference data.

Decision boundaries

The primary decision in manufactured home HVAC is whether to repair or replace the existing system — and whether the existing duct infrastructure can support the replacement equipment.

Repair vs. replace hinges on duct condition and equipment age. If belly ducts show leakage exceeding 15% of system airflow (measured by duct blaster testing per ASHRAE Standard 152), replacement of only the outdoor unit will not restore system efficiency. Full duct replacement in a manufactured home typically costs more per linear foot than in a site-built home due to access constraints.

Package unit vs. split system depends on whether interior space is available for an air handler. Package units are preferred when the original duct connection point is intact and accessible. Split systems or mini-splits are preferred when:
- The belly duct system is beyond economical repair
- Room additions or enclosures have altered the original floor plan
- The owner requires zoned conditioning

Permitting for HVAC work on existing manufactured homes in Texas is bifurcated. Alterations to the home's factory-installed systems require a TDHCA Alterations permit under Texas Occupations Code Chapter 1201. New equipment installation on a home being set up for the first time is covered under the setup permit. The Texas HVAC permit requirements page describes the general permitting structure applicable across housing types.

For licensing credential verification, TDLR maintains a public license lookup at tdlr.texas.gov/LicenseSearch. Contractors performing any refrigerant handling must also hold EPA Section 608 certification under 40 CFR Part 82, Subpart F. Refrigerant-specific obligations in Texas are outlined in the Texas HVAC refrigerant regulations section of this resource.

References

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