Instead of only blowing cold air around a building, you can cool the floor, allowing it to "sponge" heat loads from the space

Radiant Cooling

What do people love about radiant cooling?

  • By circulating cool fluid from a chiller or heat pump through a radiant panel, you can actively lower the surface temperatures in the room.  This lets you silently condition a warm space, even if it has high ceilings, like an atrium. 
  • Radiant cooling can be use in conjunction with radiant heating systems, utilizing the same network of RAUPEX® pipe, embedded in a surface. For the ultimate in efficiency, couple radiant cooling with geoexchange systems. 
  • Radiant cooling is an energy efficient way to address sensible loads in a space.
Radiant cooling PEX

San Diego courthouse radiant

Key benefits

Studies by building technology experts, including DOE and UC Berkeley’s Center for the Built Environment, recommend radiant cooling as the technology with greatest potential for energy savings at competitive or reduced investment costs.

Thermal comfort
The human body feels at its best when it can regulate at least 50% of its heat emission via radiation. Radiant cooling provides a comfortable environment by optimizing the surface temperature of the occupants’ surroundings and efficiently absorbing unwanted heat from the space.

Energy efficiency 
By surrounding you with cooled surfaces, radiant cooling allows you to set your thermostat a few degrees higher. A New Buildings Institute research found that radiant buildings are more energy efficient than 90% of comparable buildings, with 2/3 receiving an EnergyStar score of 90 or above. 

The power to choose both
You do not need to choose between optimizing comfort and energy efficiency in commercial buildings. By integrating a radiant heating/cooling system with a dedicated outdoor air system (DOAS), both of these performance attributes can be optimized.

How it Works

A hydronic radiant system takes advantage of the superior heat transfer properties of water to absorb heat energy, while air-based cooling efficiently removes excess humidity. By shifting some of the cooling load to the radiant system, air handling equipment and ductwork can be significantly downsized.

UBC Student Centre

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What capacity can you expect? 
The capacity of a radiant cooling system depends on factors such as insulation, pipe spacing, floor construction and indoor air temperatures. Under optimal design conditions, capacities of a floor system up to 16 Btu/h∙ft² can be achieved, with more typical capacities in the 8 to 12 Btu/h∙ft² range. Ceiling systems can achieve nearly double this output.

What about condensation? 
Control of humidity and entering water temperature eliminates potential for condensation.  By following ASHRAE Standards 55 and 62.1, you prevent the conditions that would allow condensation to form on radiantly cooled surfaces.
 

Where does it work best?
Radiant cooling works best in a tightly sealed building that integrates radiant with a downsized, optimized forced-air system to meet the building’s fresh air requirements. New commercial construction is the best project for radiant cooling.

How can you get optimum results?
A radiant cooling system is designed similarly to a radiant heating system, with minor adjustments in pipe diameter and pipe spacing.  By using an integrated design team approach including architects, engineers and contractors from the early phases of your project design, your building will realize superior energy performance with REHAU radiant heating and cooling systems.

Installation

Radiant cooling is achieved by embedding a network of PEXa pipes in a concrete, installation methods exist to meet design requirements.

Radiant slab

Traditional concrete slab 
Uni-directional with insulation underneath to condition the space above. This universal application of radiant cooling is frequently used in atrium spaces and a great choice for schools, municipal buildings and offices.

TABS radiant cross section

Thermally Activated Building System (TABS)
Bi-directional to condition the space above and below.This application method provides maximum energy efficiency and is great for more integrated project designs, and those that do not include a drop ceiling.

Best practice idea: A "hybrid" system pairs radiant cooling inside the buidling with a Dedicated Outdoor Air System (DOAS). This method decouples sensible and latent loads, allowing the key variables that optimize comfort and energy efficiency to be independently and precisely controlled.

Learn more about radiant

How does radiant make it in to so many zero energy buildings?  Watch this 8-minute webinar for more radiant background, energy efficiency and comfort topics.

View webinar

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RAHAU_UofC_9-1-2015 (171) - 98852

Plumber Magazine 01.20
Collaborative planning enables tight radiant heating/cooling installation timeline at university
 

Infosys - 101569

ASHRAE Journal 05.14
Variable Air Volume (VAV) system vs radiant: side-by-side comparison 
 

SDB 1 002 - 101577

HPAC Magazine 02.13
Don't Just Go With The Flow: Creating hydronic equipment schedules

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