Radiant Heating, Radiant Cooling, Overfloor, Underfloor

Overfloor System

Radiantmax OS

The Radiantmax OS overfloor radiant heating system is designed for the installation of a radiant system over the sub-floor. Our system provides the highest output for over-the-floor type radiant systems for the lowest per square foot cost in the industry. Our system uses ½" tubing on 8" centers which creates very even floor temperatures at lower water temps. It also has the ability to handle large load areas without the need for tighter spacing or supplemental heat.

The Radiantmax OS system is a 5/8" total thickness. We don't include the 5/8" furring strips with our system since the shipping is expensive and many types of 5/8" material can be used. All of the 5/8" material options can be purchased locally at any building supplier. Our designers provide a complete layout of the system, including manifold locations and zoning.

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Overfloor Radiant Heating System

Radiant Floor Heating Loop Layout CAD Drawing

Loop CAD Drawing

Underfloor System

Radiantmax US

The Radiantmax US Underfloor System is designed for the installation of a radiant heat system underneath the sub-floor. Eagle Mountain includes all the parts necessary to install a complete under-floor radiant heating system, including Radiantmax aluminum heat transfer plates and Astro-Foil reflective insulation. 1/2" BPEX tubing on 8" centers increases radiant heat transfer by over 30 percent.

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RADIANT

MrPEX® PEX-a Tubing

MrPEX® Barrier PEX tubing is Cross-Linked Polyethylene (PEX-a) manufactured in accordance with ASTM F 876. Listed to ASTM F 876/877 (CSA B137.5) and ICC-PMG 1053, and certified by NSF (NSF-rfh). Eagle Mountain uses MrPEX® PEX-a tubing as our primary radiant tubing for its unmatched flexibility, kink-resistance, and long-term reliability.

MrPEX® tubing features an EVOH oxygen barrier meeting the stringent DIN 4726 standard, restricting oxygen permeation to ≤ 0.10 g/(m³·d) — protecting all corrodible system components from oxygen diffusion damage. Sizes 3/8" through 3/4" also include a thin PE coating over the barrier to reduce noise in joist applications and aluminum heat transfer plate installations.

The molecular crosslinking is achieved through a unique peroxide extrusion process that aligns molecular chains around the tube perimeter, providing exceptional resistance to inside pressure while keeping the tubing remarkably flexible and kink-resistant.

Type	PEX-a (Cross-Linked Polyethylene)
Oxygen Barrier	EVOH — meets DIN 4726 (≤ 0.10 g/m³·d)
Sizes Available	3/8", 1/2", 5/8", 3/4", 1", 1-1/4", 1-1/2", 2"
Pressure Rating	160 psi @ 73°F / 100 psi @ 180°F / 80 psi @ 200°F
Standards	ASTM F876/F877, CSA B137.5, ICC-PMG 1053, NSF-rfh
Warranty	30 Years

MrPEX® PEX-Al-PEX

MrPEX® PEX-AL-PEX tubing is a composite pipe manufactured to ASTM F 1281-2005 (CSA B137.10) and certified by NSF (NSF-rfh). It combines an aluminum core bonded to interior and exterior layers of cross-linked polyethylene — delivering the dimensional stability and strength of metal with the longevity and flexibility of plastic.

In our systems, we use MrPEX® PEX-Al-PEX for all supply and return piping to manifolds, air handlers, and remote devices. It is also ideal for connecting heat pumps to buffer tanks and hydronic panels, as it effectively dampens vibration transfer through the piping system.

Rated to 160 psi at 200°F — well above typical system operating conditions. Not for potable water.

Type	PEX-Al-PEX Composite
Sizes Available	1/2", 5/8", 3/4", 1"
Pressure Rating	160 psi @ 200°F
Standards	ASTM F1281-2005, CSA B137.10, NSF-rfh
Use	Supply/return piping — NOT for potable water
Warranty	30 Years

MrPEX® Stainless Steel Manifolds

Eagle Mountain supplies MrPEX® stainless steel manifolds in multiple series configurations — precision-engineered for flow balancing and long-term reliability in any radiant heating system.

MrPEX Stainless Steel Manifold for Radiant Heating Systems

325 Series — 1¼" Stainless Steel (2–12 Loops)

Made from high-quality stainless steel and mounted on brackets with full port ball valves, thermometers, manual air vents, and fill/drain valves. The supply manifold features balancing flowmeters (0–2 GPM) for individual loop adjustment; the return manifold has manual on/off valves compatible with MrPEX® VA10 actuators. Branch connections: EK20. Supply/return: 1" NPT ball valves. Branch Cv: 1.39.

327 Series — 1½" Stainless Steel (2–12 Loops)

Larger-body manifold with EK25 branch connections and 1¼" NPT supply/return valves. Supply manifold includes balancing flowmeters (0–2 GPM). Return manifold has manual on/off valves compatible with MrPEX® actuators. Antifreeze resistant to 50% mix. Cv: 1.39 per branch.

328 Series — 1½" High Flow Stainless Steel (2–12 Loops)

High-flow variant with a CV of 5.35 per branch and EK25 connections. Supply side uses lockshield balancing valves per loop; return side features inline visual flowmeters (0–4 GPM) with built-in balancing. Ideal for systems requiring higher flow rates. Supply/return: 1¼" NPT.

326 Series — 1½" Type 304 Stainless Steel (3–13 Loops)

Fully assembled in 3–13 loop configurations, 3" on center, using Type 304 stainless steel. Supply/return inlets feature 1½" NPT flat gasket union connections for easy installation. G 1" × EK25 on/off valves on supply; inline visual flowmeters with built-in balancing valves on return. Compatible with all MrPEX® EK25 fitting assemblies.

Radiant Heating Systems