Engineering & Material Science

The Technology
Behind the Performance

Ultra-Fin's advantage is built into its geometry and material. Precision-extruded aluminum with a three-sided tube channel delivers thermal performance that no nail plate, foil, or concrete system can match.

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Section 02 — Technology

The Extrusion

Precision-Formed Aluminum. Not a Compromise.

Every dimension of the Ultra-Fin extrusion was developed to solve a specific thermal engineering problem: how do you maximize heat transfer from a round tube into a flat floor with zero added floor height?

Extrusion Specifications
Material
6063-T5 Aluminum Alloy
Thermal Conductivity
~200 W/m·K
Panel Width
4" (standard), 6" (wide spacing)
Panel Length
4 ft standard; custom on request
Wall Thickness
0.050" nominal
Channel Sizes
3/8", 1/2", 5/8" PEX-compatible
Contact Wrap
270° (three sides)
Max Operating Temp
180°F (82°C)
Max Operating Pressure
100 PSI
Surface Finish
Mill finish (standard)
Weight per Panel
~0.8 lbs / 4 ft panel
6063-T5 alloy is the standard for extruded architectural aluminum — excellent formability, consistent tolerances, and a thermal conductivity nearly 200 times greater than the wood subfloor it sits against.
Ultra-Fin extrusion cross-section detail
A

U-Channel

Precision-formed to grip PEX tubing on three sides with no tools required.

B

Fin Wings

Spread heat laterally across the full panel width before it reaches the subfloor.

C

Edge Lock

Adjacent panels interlock to form a continuous thermal plane over the subfloor.

Material Science

Why Aluminum Changes Everything

The choice of aluminum over steel, wood, or air isn't just about cost or weight — it's about thermal conductivity. Here's how the materials stack up.

Material Thermal Conductivity Relative to Aluminum Used In Contact Geometry
Aluminum (6063-T5)~200 W/m·K1× (Baseline)Ultra-Fin extrusion270° wrap
Steel~50 W/m·K0.25×Nail plates90° contact
Concrete / Gypcrete~1.5 W/m·K0.0075×Embedded slab360° (encased)
Softwood (subfloor)~0.12 W/m·K0.0006×Staple-up backingPoint contact
Still Air~0.025 W/m·K0.0001×Air-gap systemsNo contact

Design Insight

The Concrete Paradox

At first glance, concrete's 360° contact looks like the winner. But concrete's thermal conductivity is 130× lower than aluminum. The result: concrete stores heat well but transfers it slowly. Response times stretch to 30–90 minutes. Adjustments take hours to appear at the surface.

Ultra-Fin trades the concrete's mass for aluminum's conductivity — achieving faster warm-up, quicker response to thermostat calls, and precise temperature control, while eliminating the floor height penalty entirely.

Design Insight

The Nail Plate Gap

Steel nail plates contact the tube on one side — roughly 90° of the tube circumference. Three-quarters of the tube surface faces air. Even though steel conducts heat 4× better than concrete, that single-side contact severely limits how much heat the plate can absorb.

Ultra-Fin's three-sided wrap makes 3× more contact and uses aluminum that conducts 4× better than steel — compounding the advantage at both the interface and the emitter level.

Every BTU matters. Ultra-Fin makes sure none of them escape downward.

Fin Spacing Logic

Intelligent Layout. Variable Density.

Ultra-Fin isn't installed at the same density everywhere. Design software calculates the correct tube spacing for each zone based on room heat loss, water temperature, and floor covering — then specifies the panel layout accordingly.

Low Heat Load Zone

12" O.C. spacing
Well-insulated interior room
Low BTU/hr per SF

High Heat Load Zone

6" O.C. spacing
Glass-heavy exterior room
Higher BTU/hr per SF

Tighter spacing increases heat transfer density and thermal response rate — it does not increase total peak output beyond what the water temperature and flow rate can deliver. It reduces the time to reach that output.
Spacing Design Parameters
Standard Spacing
12" O.C. (low load)
Dense Spacing
6" O.C. (high load)
Design Variable
BTU/hr per SF required
Input: Room Heat Loss
Manual J or equivalent
Input: Water Temp
Supply °F at design conditions
Input: Floor Covering
R-value of finish floor
Output: Spacing
6" or 12" O.C. per zone
Output: Loop Length
Tubing quantity per zone

System Integration

Designed for the Full Hydronic System

Ultra-Fin doesn't exist in isolation — it's part of a complete hydronic loop. These specifications describe how the extrusion integrates with the rest of the system.

Hydronic System Compatibility
Boiler Types
Condensing, non-condensing, heat pump, solar
Supply Temp Range
90°F – 180°F
Return Temp (typical)
15–20°F below supply
Flow Rate
0.5–1.5 GPM per loop (design-dependent)
Max Loop Length
300 ft (3/8"), 400 ft (1/2")
Pressure Rating
100 PSI operating max
PEX Compatibility
PEX-A, PEX-B, PEX-AL-PEX
Manifold Type
Any standard PEX manifold
Floor Assembly Compatibility
Subfloor Material
Plywood, OSB (min. 3/4")
Joist Types
Dimensional lumber, I-joist, open web truss
Joist Spacing
12", 16", 19.2", 24" O.C.
Finish Floor: Hardwood
Compatible — max floor temp 85°F
Finish Floor: Tile
Compatible — any temp
Finish Floor: LVP/Laminate
Compatible — check mfr. max temp
Finish Floor: Carpet
Compatible — design to compensate R-value
Floor Height Added
None (sits in subfloor plane)

Let's Design Your System

Our engineering team can provide a full zone layout, tube sizing, and loop specification for your project — residential or commercial, new build or retrofit.

Request a Design Full Specifications