Radiant & Hydronics

RSS

A building with slab-on-grade heating from a cast iron boiler plans to expand. A monobloc air-to-water heat pump will provide heating and cooling for the new space via a fan-coil unit, with the existing boiler serving as backup.

Air-to-water heat pumps are gaining popularity in North American hydronic systems, but many practitioners are discovering that they operate differently from boilers.

A plumber recently asked us to inspect a home with issues related to radiant heating. The homeowner, Ronny, runs a company that builds commercial office buildings, and the plumber handles the plumbing work.

Eye candy would best describe many of the products on display at the great AHR Exposition recently held in Orlando Florida’s Convention Center.

When the system was operated, the owner complained of flow problems. The heat emitters in any given zone were only marginally warmed when their associated zone circulator was operating. The owner questioned if another circulator should be installed.

As a young and relatively new business owner, Dylan D’Amato had been looking for a signature residential project to establish his company and himself as an industry leader in the competitive New Jersey market. The design, installation and service of a radiant heating system for a 15,000-square-foot mansion will help D’Amato achieve that goal.

As electrification reshapes the HVAC market, hydronic-based heating and cooling systems stand ready to offer many design and performance benefits. One of them is the potential for thermal storage. After all, water is one of the best materials on earth for storing sensible heat.

Last month, we discussed direct-to-load hydronic heat pump systems. These systems use a variable-speed compressor and circulator to adjust heat output and flow, eliminating the need for a buffer tank or hydraulic separator.

When only the air handler is operating the heat pump is able to supply the 120 ºF water. However, when the floor heating zone and the air handler are operating at the same time and the outdoor air temperature is below 24 ºF the fluid temperature leaving the heat pump can’t climb above 103 ºF. Why is this happening, and what can be done?

The availability of heat pumps allows designers and installers of hydronic heating to include cooling. A simple method involves using a single air handler with a chilled water coil for a ducted distribution system, providing single zone cooling that can complement multi-zone hydronic heating in average houses.