In comparing hydronic chilled water and VRV/VRF systems, a new emerging factor for the chilled water side of the equation is radiant cooling. Radiant cooling is an exciting feature that avoids some of the challenges with space cooling distribution common to both types of air conditioning systems.
Comfort cooling is dependent on cooling coils and fans in the form of fan coil units or heat pumps along with filters (in the case of critical areas high efficiency filters). In lower end systems lower performance grills and air diffusers are commonly used, which can aggravate the comfort problem by dumping cold air on occupants. A radiant cooling system, however, avoids these problems since chilled air is not distributed through an air distribution system, as described above, but rather by a combination of radiant and natural convection. This only serves to improve IAQ.
Radiant cooling systems are now coming of notice here in the U.S. and design engineers are turning to them to achieve high comfort levels. Radiant cooling, like most hydronic-based applications, is common in Europe, but the trend line here in the U.S. is encouraging. There are a number of domestic radiant cooling manufacturers around today with successful installations.
At Taco’s Milton, Canada operation we have installed a chilled beam system to cool the office and training areas during the summer months.
In this application active chilled beams were employed along with chilled ceilings to supplement. Together they work to reduce fan energy by a factor of 10, since the only air circulation that’s required is from the DOAS. This system supplies just enough treated, dehumidified outdoor air to slightly pressurize the building, negating natural infiltration of humid outside air. Like its counterpart, radiant heating, the market for radiant cooling will only grow larger in the years ahead, now that use of 100-percent DOAS is understood to be an effective remedy for the dehumidification issue previously associated with radiant cooling.