Radiant Heating & Cooling: More efficient HVAC technology

Over the past decade, the radiant cooling and heating system widely used throughout Europe has shown steady growth in North America

Radiant heating and cooling?is a category of?HVAC?technologies that?exchange heat?by both?convection?and?radiation?with the environments they are designed to heat or cool.

Heat transfer occurs between two substances until thermal equilibrium is reached due to the temperature difference between them. According to the second law of thermodynamics, heat does not move from low temperature to high temperature. In other words, heat naturally moves from high temperature to low temperature. Among heat transfer methods such as conduction, convection, and radiation, the radiant cooling and heating system mainly focuses on radiation, but it also utilizes the other two heat transfer methods. This mechanism could be used in both multifamily/residential indoor heating & cooling.

Indoor Radiant Heating

When this applies to indoor heating, unlike conventional methods such as radiators which mainly rely on convection heating, Radiant heating warms a building through radiant heat.

Systems combining radiation, convection, and conduction have been used since Roman times with hypocaust heating. Underfloor radiant heating has been popular in South Korea and China for a long time. In this system, heat energy is emitted from a warm surface like a floor, wall, or overhead panel, heating people and objects in the room rather than directly warming the air. Compared to conventionally heated buildings, the internal air temperature in buildings with radiant heating can be lower while still providing the same level of comfort when the perceived temperature is adjusted to be equivalent. One significant benefit of radiant heating systems is the reduced air circulation within rooms, resulting in fewer airborne particles being dispersed

Indoor Radiant Cooling.

Radiant cooling involves the use of cooled surfaces to primarily remove sensible heat through thermal radiation, with secondary effects from convection. According to ASHRAE, radiant systems are defined as temperature-controlled surfaces where 50% or more of the design heat transfer occurs via thermal radiation. Hydronic systems are examples of radiant systems that use water to cool these surfaces. Unlike "all-air" air conditioning systems that only circulate cooled air, hydronic radiant systems circulate cooled water through pipes in specially mounted panels on a building's floor or ceiling to maintain comfortable temperatures. Another system is typically used to provide ventilation, dehumidification, and possibly additional cooling. While less common than all-air systems for cooling, radiant systems can offer advantages over all-air systems in certain applications

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Benefits of using Radiant Heating & Cooling system in Multifamily & SFR operations

1.?The biggest benefit coming from using radiant cooling systems consume less energy compared to traditional cooling systems. The amount of energy saved with radiant cooling varies based on the climate. On average across the US, savings are around 30% compared to conventional systems. In cooler, humid regions, the savings might be around 17%, while in hotter, arid regions, savings can reach up to 42%

2.?There are six factors that influence the thermal environment perceived as comfortable by humans: air temperature, radiant temperature, humidity, air velocity, clothing, and metabolism. Traditional air systems maintain comfort by controlling indoor temperature and relative humidity, overlooking the impact of radiant temperature on human comfort. Generally, humans emit more heat through radiation when in a comfortable state. In terms of heating, radiant systems provide a more comfortable environment compared to traditional air systems.

3.?You can save operating and maintenance costs. The piping installed within concrete slabs does not require maintenance, unlike typical HVAC systems. This ease of maintenance contributes to cost savings compared to conventional air systems.

4.?It also gives a higher degree of freedom in architectural design. In the case of radiant cooling and heating systems, the water pipes installed within the floor slab and the exposed equipment such as air conditioners, ducts, grilles, and diffusers can be aesthetically adjusted to suit the building's purpose. This allows for minimizing the space needed for each material installation and potentially reducing the floor-to-floor height. Additionally, radiant slabs are designed to effectively manage direct solar loads, enabling effective temperature control even in high-ceilinged large spaces