What “Mobile Home AC Sizing” Really Means
Sizing isn’t just “tons per square foot.” Manufactured and mobile homes have unique construction, ducts, and electrical rules that change the math. The goal is simple: a system that holds temperature on a design-day, removes humidity, and doesn’t waste energy or wear itself out. Right-sized equipment runs steady, not frantic; it feels even room-to-room and keeps noise down. We’ll walk through how climate, insulation, sun exposure, duct quality, and power service all shape the final choice. When you’re ready to compare equipment, start with our plain-English HVAC Sizing Guide and talk options with our team. If you’re learning ductless, packaged, or split systems, we’ll point you to the right product families as we go no fluff, just what works for manufactured homes.
Know Your Home Type and Size
Start with the basics: single-wide vs. double-wide and total conditioned square footage. As a ballpark, single-wide homes often land around 1.0–2.0 tons, depending on size and construction. Double-wide homes typically range from about 1.25–4.0 tons because of larger floor areas and multi-section layouts. These are context numbers—final sizing depends on climate, insulation, windows, and ductwork quality. If you’re replacing an old unit, don’t assume the existing tonnage was right; older installs were often oversized. Jot down your square footage, note any additions or enclosed porches, and list the rooms that run hot or cold. That quick “site sketch” will help a pro or our Design Center team validate the load and recommend equipment without guesswork.
Match Capacity to Climate Zone
Climate matters a lot. Think of Zone 1 as cooler and Zone 5 as extremely hot. Hotter zones push capacity per square foot upward because the AC must overcome higher outdoor temperatures and stronger sun loads. Cooler zones can often use less capacity without sacrificing comfort. Where people get tripped up is using the same “rule per sq. ft.” regardless of climate. Instead, note your local design temperatures and humidity. In hotter, humid regions, latent (moisture) load matters as much as temperature. If you’re unsure which zone you’re in, a quick call to a local pro or our Help Center can point you in the right direction. Bottom line: climate zone fine tunes the tonnage, even when two homes are the same size.
Insulation, Sun, and Windows (The Hidden Load)
Two identical floor plans can need different AC sizes. Why? Envelope differences:
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Insulation levels in the roof, walls, and underbelly
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Sun exposure (shade vs. direct sun; dark vs. light roof)
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Window area & orientation (big west-facing glass raises afternoon loads)
Mobile homes often have lighter construction than site-built homes, which can increase sensible heat gain. If you’ve upgraded windows, sealed air leaks, or added shade, your real load may be lower than a rule-of-thumb suggests. Conversely, thin shades, older single-pane windows, or a dark, sun-exposed roof can push capacity higher. Capture these details before you pick equipment. If you’re planning a ducted replacement, consider matched air handlers and R-32 condensers to ensure the coil and outdoor unit are sized and rated together.
Ductwork That Makes or Breaks Sizing
Good ducts let a right-sized AC act like a right-sized AC. In many manufactured homes, ducts run in the under-belly and must be properly supported (commonly every ~4 feet) to prevent sagging that restricts airflow. The furnace-to-trunk connection is the highest pressure point—sealing and strapping here matter most. In double-wides, the crossover duct between sections must be tight and insulated; leaks here can make a new system feel undersized. Before you blame the equipment, measure static pressure and check for crushed runs, disconnected boots, and unsealed seams. If you’re replacing equipment, budget time and materials for duct fixes and consider accessories like line sets and proper transitions so the new system can actually breathe.
Electrical: The Box Has to Back the Box
Mobile homes follow specific electrical rules. Larger condensers and packaged units often need 220V service, correctly sized breakers, and wire gauges that match nameplate amperage. Grounding must meet HUD-type requirements, and disconnects should be mounted where a tech can safely service the unit. Undersized circuits lead to nuisance trips and hard starts that shorten compressor life. When you shop equipment, compare the MCA (Minimum Circuit Ampacity) and MOCP (Max Overcurrent Protection) on the spec sheet to what you actually have. If it’s not a match, plan an electrical upgrade alongside the HVAC swap. Our packaged options simplify wiring and airflow; browse residential packaged systems if you need an all-in-one, code-friendly solution.
Avoid the Two Classic Sizing Mistakes
Oversizing sounds safe but causes:
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Short cycling (poor humidity control, clammy feeling)
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Higher bills and shorter equipment life
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Temperature swings and noisy starts/stops
Undersizing is the opposite problem:
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Runs constantly yet struggles to reach setpoint
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Excess wear on components
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Hot rooms, poor comfort, and higher energy use anyway
In mobile homes, both mistakes show up faster because ducts and envelope loads are less forgiving. If you’ve had moisture issues, that’s often a sign of oversizing or duct leakage. If afternoons are brutal but nights are fine, you may be undersized or dealing with solar gain. Balance capacity, airflow, and dehumidification rather than chasing the biggest tonnage you can afford.
Why Manual J Is the Grown-Up Way to Size
Rules of thumb are a starting point, not the answer. A Manual J load calculation accounts for:
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Your home’s actual insulation and construction
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Real window specs and orientation
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Duct layout and sealing quality
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Local climate/design temperatures (not just “it’s hot here”)
Because manufactured homes have unique assemblies and duct paths, a formal load calc pays off. It also protects your investment matched to the load, a system will cycle correctly, manage humidity, and last longer. If you want help, send measurements and photos through our Design Center or use our quick Quote by Photo tool. We’ll translate your details into a clear sizing and equipment plan you can trust.
Choose the System Style That Fits Your Home
Different homes call for different equipment:
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Packaged units: All-in-one cabinets for tight footprints and straightforward service.
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Ducted split systems: Traditional outdoor condenser + indoor coil/air handler.
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Ductless mini-splits: Great for add-ons, hot rooms, or when ducts are poor.
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PTAC / Through-the-Wall: Useful for zone cooling or when ducts aren’t practical. See PTAC units and through-the-wall units.
If you’re in a very hot climate or need heating too, consider heat pump variants in the same families.
