Small-Duct Retrofits
Modern comfort for old homes lacking centralized ductwork
Small-duct high-velocity systems thread flexible tubing through your existing home without tearing up plaster or historic trim. Perfect for older North Shore homes, these systems pair seamlessly with electric heat pumps for quiet, year-round comfort.
The process
How we retrofit small-duct systems into older homes
Every project starts with careful design, not guesswork. We look at your house, your comfort issues, and your goals, then build a plan that fits your home instead of forcing your home to fit the system.
01
02
03
04
Consultation & load calc
System design & routing
Installation & protection
Commissioning & fine-tuning
We walk your home, listen to what’s not working, and run a Manual J load calculation so we’re sizing the system to your actual house, not a rule of thumb.
We design the air handler location and small-duct routes through closets, soffits, and attic spaces to protect plaster, trim, and finished rooms as much as possible.
Our crew installs the air handler, tubing, and outlets with dust control and floor protection, coordinating with you around pets, kids, and daily life in an older home.
We balance airflow, check temperatures room by room, and fine-tune the system so your home feels even and quiet—not “blasted” in some rooms and weak in others.
The systems we install
SpacePak and The Unico System
SpacePak and The Unico System are small-duct high-velocity systems designed to bring central air (and often heating) to homes that were never built for big sheet metal ducts.
Both systems can deliver whole-home cooling and, when paired with the right equipment, heating as well—often through the same small outlets.
The right design depends on the home: available chases, attic and basement space, existing radiators, and how much of the house you want to condition.
- Small, discreet outlets instead of large floor or wall registers
- Strong fit for older homes without existing ductwork
- Compact supply tubing routed through existing framing cavities
- Pairs with central cooling, heat pumps, hydronic coils, or hybrid systems
- Preserves plaster, trim, ceilings, and historic character
- Excellent humidity removal when designed and commissioned correctly
- Variable or adjustable-speed blower technology for quieter operation
- Designed around the house: load calculation, routing, and outlet layout
SpacePak or Unico? Both are proven small-duct retrofit systems. SpacePak comes in one package unit making installation easier at lower cost. The Unico System is especially useful when mechanical space is tight, with modular air-handler options and compact configurations. We'll specify the right system after we understand the house.
Small-duct systems are not magic. Design matters.
A small-duct system can be quiet, even, and discreet. It can also be noisy or uneven if it is rushed. Poor outlet placement, high static pressure, weak return air, bad routing, or skipped balancing can ruin a good idea. We design the layout first, then install and commission the system so the house feels right.
Good fit / Poor fit
Good fit
Older homes with no ducts
Plaster walls and finished rooms
Radiator homes adding cooling
Homeowners who care about appearance
Poor fit
Homes where basic ducted replacement already works well
Very tight homes with no routing path
Budgets that cannot support custom routing
Projects needing the cheapest possible cooling
Small-duct retrofit investment
Most whole-home small-duct retrofits fall between $15,000 and $45,000 before any related equipment, electrical work, or rebates. Final cost depends on home size, attic or basement access, number of outlets, air-handler location, and whether the system is paired with a heat pump.
TYPICAL RANGE
$15,000 to $45,000 before related upgrades
BEST FIT
Older homes where traditional ducts would require major disruption
SYSTEM LIFE
25+ years with good installation and maintenance
Perfect candidates for small-duct
If your home looks like this, small-duct was built for it:
Small-duct systems are specifically engineered to provide modern climate control in structures where traditional HVAC installations would require invasive renovations or unsightly bulkheads.
Pre-1950 homes with plaster walls and original trim
Victorian, Queen Anne, and other detailed older styles
Craftsman bungalows and 1920s–1940s brick homes
Brownstones and narrow, tall floorplans
Gut rehabs where you want central air without big soffits
Additions, sunrooms, and finished attics that never stay comfortable
Historic landmark buildings where you need a low-impact install
Multi-family retrofits where space for ductwork is tight
Radiator homes adding cooling without touching the radiators
Bonus rooms over garages and tricky second floors
Tight utility rooms where a traditional air handler won’t fit
Homes where you’ve been told “there’s no way to add central air”
The electrification path
Small-duct systems deliver the air, while heat pumps provide the power
Think of it as a partnership: the small-duct system is the air delivery (how comfort reaches you through your home), and the heat pump is the equipment (the outside unit that actually creates the heat). Together, they allow most older North Shore homes to move away from gas without the invasive ductwork of traditional units.
The choice: all-electric
A low-carbon heating and cooling solution
The choice: hybrid systems
Electrification with a gas safety net
A cold-climate heat pump replaces your furnace and A/C entirely. When paired with small-duct delivery, it provides quiet, uniform warmth even in Chicago's deepest winters—provided the system is designed specifically for our local load requirements. You get quiet comfort, zero on-site emissions, and total energy independence from gas.
For very tricky homes or large Victorian residences, a hybrid path uses a heat pump for 90% of the year while keeping a furnace or boiler as a safety net for the few extreme cold snaps when supplemental heat is required. You still cut gas use significantly and improve summer cooling comfort while retaining a familiar backup source.
Why it works
The numbers behind small-duct performance.
2–4
30%
3–6
Typical number of small outlets per main room, depending on size and layout.
Better dehumidification than conventional forced-air when properly designed and commissioned.
Days for a whole-home installation, depending on size and complexity of the house.
Our small-duct services
Design, installation, and ongoing support for older homes.
NEW INSTALLATION
Design-first approach
Every project starts with Manual J load calculation, routing plans, and outlet layout so the system fits your house and protects plaster, trim, and finished spaces.
REPLACEMENT & UPGRADE
System improvements
Already have a system that underperforms or is aging? We can replace equipment, improve duct routing, and rebalance airflow to bring it up to today’s standards.
MAINTENANCE
Annual tune-ups
We provide ongoing maintenance for small-duct systems, including cleaning, checks, and performance tuning to keep things quiet, efficient, and reliable.
Tight-Space Mastery
Expertly navigating cramped attics and narrow utility chases where traditional ductwork simply won't fit, ensuring full coverage without compromise.
Historic Preservation
Specialized techniques to protect original plaster, intricate trim, and decorative ceiling details during installation for a low-impact upgrade.
Heat Pump Pairing
Seamless integration with modern cold-climate electric heat pumps, allowing your older home to transition away from fossil fuels efficiently.
Precision Zoning
Customized airflow designs that ensure consistent temperatures across multi-story Victorian floorplans and challenging room layouts.
Noise Engineering
Meticulous commissioning and balancing to achieve silent, high-velocity operation, removing the 'whoosh' common in poorly set up systems.
Lifetime Service
Dedicated annual maintenance and expert technical support to keep your small-duct system running at peak performance for years to come.