High Velocity System

What Is a Small Duct High Velocity Air Conditioning System?

A Small Duct High Velocity (SDHV) system is a smart way to add modern central air conditioning to homes that don't have room for traditional bulky ductwork. Instead of large rigid ducts, SDHV uses small, flexible supply tubes that deliver conditioned air at higher pressure and velocity, quietly, efficiently, and with minimal disruption to your home.

How It Works

SDHV systems push conditioned air through narrow flexible tubes (about 2 inches in inner diameter) at a higher static pressure than traditional ductwork. The high-velocity airflow mixes with the room's existing air, creating a gentle, even temperature throughout the space, without the drafts or hot and cold spots you get from conventional vents.

A complete system is built around three main parts: a central air handler that works with the outdoor unit to heat and cool the air, a compact main plenum that distributes it, and the small, flexible supply tubing that carries it into each room.

A cutaway view of how a Small Duct High Velocity system fits a traditional home: a central air handler and compact main plenum feed small, flexible supply tubing that weaves through ceilings, walls, and floors to discreet outlets in each room.

Why It's So Quiet

The supply tubes are engineered as sound attenuators, sometimes called duct silencers, because of their sound-absorbing design. Each tube has an inner core wrapped in insulation, with an outer vapor barrier that blocks moisture and reduces thermal loss.

The small, flexible supply tubing is wrapped in insulation for quiet operation, with outlets available in a range of finishes to match any room.

Why It Fits Where Other Systems Can't

Because the supply tubes are small and flexible, they can be routed through tight spaces such as attics, ceiling cavities, crawlspaces, and even between wall studs. That's why SDHV is the go-to solution for:

• Older and historic homes without existing ductwork
• Renovations where you don't want to tear up walls and ceilings
• Modern designs where bulky vents would ruin the aesthetic
• Room additions and finished basements

Why Choose Small Duct High Velocity?

• Fits in any space: Because the supply tubing is small and flexible, an SDHV system installs almost anywhere, even in homes with little or no existing ductwork. You get true central air without the major construction a conventional system would demand.
• Whisper quiet: Between sound-absorbing insulated tubing and air handlers mounted on vibration pads, an SDHV system runs remarkably quiet. Most homeowners notice the even, comfortable temperatures long before they notice any sound, if they notice it at all.
• More efficient: Traditional systems with bulky metal ductwork lose conditioned air through leaks, gaps, and seams, sometimes wasting up to 30% of what they produce. SDHV tubing has far less surface area and much tighter joints, so very little air is lost. Professionally installed by TOPTEC's certified technicians, your system delivers maximum efficiency and lower energy bills year after year.

Why Choose SDHV System Installation?

• Little to no remodeling required: Our technicians route the flexible tubing through the spaces your home already has, so there's no need to tear open walls or ceilings to make room for ductwork. Your home stays intact, the work stays clean, and installation moves quickly.
• Fits your style: Outlets can go in floors, ceilings, or walls, wherever they fit best, and they're small and discreet by design. With a wide range of outlet styles available, your system blends into any décor or architecture, from historic Victorians to modern minimalist builds. You won't notice the vents, just the comfort.
  

A discreet round outlet set flush into the hardwood floor delivers even comfort without an obtrusive vent.

• Draft-free, consistent comfort: SDHV systems maintain temperature variation of no more than 2°F throughout your home. Instead of blasting air into a room the way traditional systems do, SDHV uses gentle, even airflow that blends the air throughout the space, so every room, every floor, and even floor-to-ceiling stays at the temperature you set.

Ready to See If SDHV Is Right for Your Home?

Get a free, no-obligation consultation from TOPTEC's certified technicians. We'll walk you through whether SDHV is the right fit for your home, and provide a clear, upfront quote.