Why Manufactured Homes Are Different and Why It Matters
Manufactured/mobile homes run high window-to-wall ratios, shallow floor cavities, and often lack attics or basements. That means limited room for supply trunks, tight crossover runs between sections, and poor access for sealing. Add HUD requirements (thermal protection, ventilation rates, duct insulation minimums, and sealing) and the margin for error shrinks. Practically, oversized equipment short-cycles, duct losses spike, and rooms at the far end starve for airflow.
What works: equipment that doesn’t rely on bulky ducts, or systems purpose-built for manufactured housing. What fails: trying to shoehorn a site-built spec into a chassis not designed for it.
HUD requires minimum R-4.0 on supply ducts and airtight connections. If you inherit older flex runs with loose boots, budget time and materials for rehab.
Help Center, Accessories.
Ductless Mini-Split Heat Pumps: The Lead Solution
Modern ductless mini-splits check three boxes at once: efficiency, space, and control. With SEER ratings commonly 20+, they outclass typical 13–16 SEER manufactured-home systems and avoid the biggest pain point—ducts in constrained cavities. Indoor heads mount on walls, ceilings, or short-throw floor consoles; the penetrations are small, and line sets route cleanly. Multi-zone setups give room-by-room control, so you only condition occupied zones. In cooling-dominant markets, they slash runtime; in heating season, cold-climate models deliver steady heat without strip-heat penalties.
specify line-set lengths, elevation changes, and flare torque values upfront; pre-insulate lines with UV-resistant sleeves.
When Packaged Heat Pump Systems Make More Sense
A packaged unit places the coil, compressor, and blower in one cabinet, solving placement and service access in tight homes. HUD-approved packaged designs flatten install complexity and keep connections straightforward. Wall- or pad-mounted, they can sit outside the thermal envelope with proper sealing—or within it when mounted through the wall per manufacturer instructions. Expect solid efficiency (roughly mid-teens SEER equivalents) and a predictable bill of materials.
Where they win: replacement of aging furnace/AC combos where ducts exist and are salvageable; parks preferring single-cabinet serviceability; homes with vandalism/weather-exposure concerns.
Split AC + Mobile-Home Furnace: Still Viable With Caveats
Traditional split systems can perform well if sized tightly and paired with compliant ducts. Most manufactured homes land between 1.5 and 4 tons; go by Manual J, not rules of thumb. Undersized returns and leaky boots will negate the best condenser you can buy. Stick with R-4.0 minimum supply insulation and seal every joint. If the belly space is unconditioned, step up to R-8 on exposed runs. Measure external static pressure with all registers open; high ESP hints at crushed flex or undersized returns.
Sizing That Avoids Short-Cycling (With a Quick Table)
Start with 20–30 BTU/ft² and adjust for climate zone, insulation quality, window orientation, and ceiling height. Then run a proper Manual J to finalize loads. Remember: manufactured homes often have higher infiltration and solar gains relative to floor area.
|
Home Size |
BTU Range |
Typical System |
|
400–800 ft² |
9,000–15,000 |
1–1.5 tons |
|
800–1,200 ft² |
15,000–24,000 |
1.5–2 tons |
|
1,200+ ft² |
24,000+ |
2–3 tons |
West-facing glass can add 10–15% to cooling load; kitchens add sensible gains near cooking times.
For multi-zone mini-splits, oversize the outdoor unit only modestly; diversity helps, but too big still kills dehumidification. Sizing Guide custom help via the Design Center.
Ductwork: Seal First, Then Insulate (Crossover Included)
Leaky manufactured-home ducts can dump ~20% of capacity into voids. Prioritize sealing, then insulate. On double-wides, the crossover duct is the usual suspect: crushed, loose band clamps, or torn vapor wrap.
Quick diagram (top view):
Supply trunk ──┬── Branches → Rooms
[CROSSOVER] → Second section
│
Return trunk
What to do:
-
Pressure-seal internally (e.g., aerosolized sealant) when access is poor.
-
Hand-seal with mastic + UL-181 metal tape at boots and joints.
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Support ducts off the ground; re-strap sagging flex every 4–5 ft.
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Wrap exposed or belly-space runs to R-8 where feasible.
Shopping list: Accessories & tapes.
Ventilation & HUD Code: Hitting the Numbers, Not Just the Letter
HUD targets whole-house ventilation ≈ 0.035 CFM per ft² of living area and requires separation distances between intakes and exhausts. In practice, many homes still rely on intermittent bath fans and range hoods that don’t hit continuous rates. Aim for quiet, continuous-low strategies that won’t get switched off—ECM bath fans with delay/off timers, or dedicated small ERVs where climate and budget make sense.
Code minimums trail current good practice for many site-built programs. If moisture or odor complaints exist, design for a bit more CFM with measured pressure balance.
back-draft dampers on range/bath fans, labeled service disconnects, and screened terminations set to manufacturer clearances. Keep intakes away from dryer vents
Help Center.
Building Envelope Upgrades That Multiply HVAC Gains
Right-sizing equipment is step one; tightening the envelope locks in savings. Focus on: belly insulation and vapor barrier repairs, air-sealing rim and marriage lines, window/door upgrades, and roof-cap insulation. Small air-sealing jobs (weatherstripping, caulk at window trim, foam at plumbing/electrical penetrations) often beat flashy add-ons in ROI.
Pair envelope work with smart controls: mini-split zoning targets occupied rooms; set coastal homes to a mild dry-mode for shoulder seasons to control humidity.
After envelope work, re-verify static pressure and airflow; tighter homes can change return/supply balance. Through-the-Wall heat pumps where a single zone is all that’s needed.
Cost, Savings, and Simple Payback (Realistic Ranges)
Expect installed mini-split systems around $3,000–$8,000 depending on zones and line-set complexity. Operating savings commonly land 30–60% versus older ducted setups—bigger in high-kWh markets or where strip heat was primary. Packaged systems run moderate upfront costs and simplify service, with solid step-down bills from legacy units. Well-executed split systems can be cost-effective if ducts are in good shape.
Back-of-napkin payback:
Annual Savings ($) = (Old kWh − New kWh) × Rate
Simple Payback (yr) = Installed Cost / Annual Savings
Include avoided duct rehab in your ROI. Skipping a belly-crawl duct replacement often makes a multi-zone mini-split the clear winner.
See: Financing options.
Installation & Maintenance: The Checklist That Prevents Callbacks
Installation: verify branch-circuit sizing and breaker type; confirm refrigerant line OD/ID and max length/elevation; slope and trap condensate; torque and nitrogen-braze (where applicable); evacuate to ≤500 microns with decay test; set charge per spec; commission with superheat/subcooling logs. For packaged/split units, check duct leakage and ESP before handoff.
Maintenance: change filters every 1–3 months, keep outdoor coils clean and clear, inspect and re-seal duct connections annually, and check mini-split drain pans/pumps each spring.
leave wiring diagrams, charging data, and owner settings at the panel.
Snap photos and request a quote via Quote by Photo, or engage the Design Center for a full layout.
