RADIANT HEATING, COOLING & SNOWMELTING SYSTEM DESIGN

Commercial Radiant Projects

United Airlines Maint. Facility, IN 2.6 million sq.ft. of Radiant Floorheat and Snowmelting

One of my first projects, this was (at the time) the largest single project radiant floorheating system in the world (it may still be!). It comprised 11 hangers, each with two bays of 72,000ft² with an 80’ ceiling. It was quickly determined by owners and engineers that a typical roof-top air system was not going to work here. Higher efficiency and quicker recovery made radiant the logical choice for this project, plus the heat was at the floor where the mechanics were working.

25mm Pextron tubing at 800’ maximum circuit length was installed on the rebar mat at 18” centers on average, and tied into 1½” brass manifolds. Once final tubing layout drawings were approved, I forwarded the coil schedules to our tubing supplier in Germany who extruded and tagged each circuit individually to minimize waste. Several 40’ containers of tubing were shipped directly to the site when required for each hanger. Operating costs were determined to be between 30% and 50% less than that of a conventional air system!

Read full story in Contractor magazine

FedEx Sorting Facility, Boston, MA 90,000 sq.ft. of Radiant Floorheat and Snowmelting

A new overnight package distribution center was built to replace a very old and much smaller facility, with a big emphasis on energy-efficiency and worker comfort. During normal operation, all overhead doors are open from 5am until noon to allow for the constant deliveries, so there was a very high heat-loss factor. Because of its quick recovery and overall energy efficiency, a radiant floorheating system was installed. After the first year of operation, the owners did their own energy consumption analysis to compare to their old building which had gas-fired roof top units. Therms per square foot for the old building were 1.02, while the new building used just 0.51 – exactly 50% less!

The building manager also noted that the workers were much more comfortable (and more productive) in the new building – another added bonus of radiant floorheat.



Museum of Fine Art, Boston Radiant Cooling and Heating

The 280,000ft² new east wing addition included a 65ft high glass-enclosed, tree-lined courtyard, affectionately known as the ‘Jewel Box’. The obvious mechanical challenges were; what heating and cooling systems to use, and how to position any ‘wet’ system so it is not over any gallery. The natural choice for heat was of course radiant positioned in the new concrete floor. After much discussion and number crunching, my company’s proposal to utilize the floor system for cooling was also adopted to extract as much heat from the space as possible. This resulted in a net savings for the museum as the mass displacement air system that was to be installed was now greatly reduced in size!


Royal Ontario Museum, Toronto, Canada Multi-level Radiant Floorheating

Considered to be one of the most challenging construction projects in North America for its engineering complexity and innovative methods, the Lee-Chin Crystal is composed of five interlocking, self-supporting prismatic structures that co-exist but are not attached to the original ROM building, except for the bridges that link them. The exterior is 25% glass and 75% extruded-brushed, aluminum-cladding strips in a warm silver color. The steel beams, each unique in its design and manufacture and ranging from 1 to 25 metres in length, were lifted one by one to their specific angle, creating complicated angle joints, sloped walls, and gallery ceilings. Approximately 3,500 tons of steel were used to create the skeleton, and roughly 9,000 cubic metres of concrete were poured. Very complex tubing layout on each of 5 levels because of the shapes of the crystals, with most utilities and services routed through the floor, making this the toughest obstacle course I’ve had to design around!