New Mexico company 'rolls' out radiant heating design
When Miller Bonded Inc. (MBI) decided to design its new pipe fabrication facility in Albuquerque, NM, the HVAC mechanical contractor not only wanted to streamline production, it also wanted an energy-efficient building.
Keith Wilson, Miller Bonded CEO, said the company decided “to move much of our prefabrication activities from the field to the shop environment to maximize productivity, quality, and safety.”
The facility would save time by having prefabricated materials — water heaters, pump skids, VAV units, heat pumps, etc. — ready to go for the general contractor on-site. Controlled conditions at the facility would also maximize worker safety, which faces higher risks on the job site.
As part of implementing this new strategy, Miller Bonded management wanted sustainable technology wherever possible. The company also realized it was within reach of LEED® Gold certification.
As a result, Miller Bonded incorporated sustainable design throughout the building. Solar thermal panels, sensor-activated lighting, and evaporative cooling were among the green technologies designed into the construction.
When it came to heating the large, 16,000-sq-ft facility, there was the conventional option of forced-air. However, that option would have been less consistent with LEED standards. The alternative option — a hydronic radiant floor heating system powered by solar energy — was much more attractive to management. Coupled with the solar panels for providing hot water, the technology would not only slash energy costs to a minimum, but — through an application called the Radiant Rollout™ Mat — would significantly shorten installation time and costs as well.
Because radiant heating warms people and objects at or near floor level, the technology is especially effective in large commercial spaces with exceptionally high ceilings. In a conventional forced-air heating system, hot air blows out of the registers and rises to the top of the space where it quickly sheds heat and then drops back down as it cools. The higher the ceiling the greater the energy to heat such a space.
“Because radiant heating warms people and objects directly — as opposed to the surrounding air — occupants are more comfortable, while often using less energy,” said Mark Hudoba, director of heating and cooling at Uponor North America.
Moreover, because the heat is more evenly circulated, there is less need to “overheat” a space, in order to compensate for spaces that seem too cool because of drafts or poor insulation.
According to Wilson, the new facility was to have around a 30-ft high ceiling. It would have taken forced air a significant amount of time and energy to heat such a large area. Furthermore, with the frequent opening and closing of doors in the facility, warm air would be escaping quicker than the blowers could replace it. On the other hand, radiant heating would warm the concrete floor and everyone standing on it. Should cold air enter, the concrete pad would still retain its heat.
“We aimed to have comfort within the first six to eight feet and didn’t care how warm or cold it was near the roofline,” explained Wilson. “Radiant heating would help us achieve that.”
An added benefit — the radiant technology would be powered by 30 solar panels. This proved to be the ultimate in energy efficiency and environmental sustainability, and Miller Bonded would pay next to nothing in heating costs as a result.
After deciding to install radiant floor heating in the new facility, Miller Bonded needed to decide how to install it. Traditionally, a radiant floor is installed by manually arranging loops of embedded PEX tubing and securing it with plastic ties to wire mesh before the concrete pad is poured.
Wilson and his team were planning on moving forward with this conventional method until Uponor suggested a new option called Radiant Rollout Mats. Featuring a custom-designed, prefabricated network of PEX crosslinked polyethylene tubing, the company claims these mats allow for a fast and efficient method to install radiant heating systems in large commercial areas.
The wide open, unobstructed nature of Miller Bonded’s new facility made it an ideal fit for the mats. Although they can be installed in variously shaped spaces, the mats are most easily placed when they can simply be rolled out across a large area. Additionally, since the mats are prefabricated, they offer the possibility for significant time savings during installation.
Miller Bonded’s only initial concern revolved around the need to have several joints between the mats buried in the concrete. In conventional installations, the connections between the tubing and the manifolds are located above the floor, allowing for easy modifications and repairs if necessary.
“Deciding to go with the Radiant Rollout Mat came with a lot of trust and confidence in the manufacturer,” admitted Wilson, “We believed that as long as we installed the product correctly, they would back it up.”
Instead of manually looping the tubing through the floor, the task consisted of rolling out and securing the prefabricated mats onto the designated area. Workers said the installation saved time and eliminated physical aspects associated with the job.
The Radiant Rollout Mats are normally secured using soil stakes and do not require connection to wire mesh, leading to savings in material costs. Still, Miller Bonded opted to include the mesh to maximize the floor’s structural rigidity, so that it would be better able to support the heavy pipe-fabrication equipment.
“We wanted the wire mesh included for our particular needs, even though it wasn’t necessary for the actual mat,” explained Wilson.
Since the installation, the solar-powered radiant system has consistently kept Miller Bonded’s facility warm for its staff. Even when the doors open in the winter, it takes little time for the fab shop to warm up because, as previously noted, the concrete slab does not readily cool.
Meanwhile, the solar panels provide nearly free heating even during the coldest months, according to Wilson, who says that the system’s backup boiler is seldom needed to keep the radiant system water at the correct temperature. Four years after the pipe fabrication shop opened, the investment in an environmentally sustainable building design (including solar panels) has proven to be a prudent decision for Miller Bonded.
“From installation of the mats to the performance of the system, it couldn’t have worked out better,” he says. “We are absolutely thrilled with how it turned out.” ES