Matt Millard, owner of Performance Mechanical in Edgartown, Massachusetts, loves to experiment with new technologies. His career has spanned commercial piping and mechanical and residential heating systems. He currently installs plenty of efficient air-to-air heat pumps but recently wanted to step up to hydronic radiant heating for his own home addition using an air-to-water heat pump.

Millard added a 1,500-square-foot multi-purpose room and extra bedroom with a bathroom over his attached garage workshop. This is part of his successful grand strategy to make his house Net Zero Energy.

The mechanical

Simple as can be, Millard piped the warm water from the outdoor monoblock air-to-water heat pump into the silver buffer tank, and from there, to the radiant heat above using a variable speed pump.

“While my company now installs many air-to-air heat pumps, I see that the new propane refrigerants coming down the pipe will severely restrict my ability to put refrigerant lines in a home,” Millard says. “That’s why I wanted to try out the Chiltrix air-to-water heat pump matched with Ecowarm RadiantBoard. The Chiltrix is a a monoblock design that keeps the pre-charged refrigerant outside. I think my future may easily be installing hydronic systems indoors with the condenser refrigerants staying outdoors.”

Ecowarm’s RadiantBoard was a great performance a match for the system, Millard notes.

“I selected Ecowarm RadiantBoard to match with my air-to-water heat pump because these very low-mass, aluminum-clad panels operate more effectively at lower supply water temperatures than many other types of hydronic distribution,” he explains. “For those who track heat pump performance, the lower supply water temperature requirements of Ecowarm RadiantBoard results in higher heat pump capacity at low ambient temperatures we experience in New England.”

The Millard home has 14-foot ceilings in its great room with a couple of big windows.

“I’ve found that radiant heat is a more effective and efficient means of heating large volume spaces than forced air, allowing me to avoid ceiling fans to circulate hot air,” Millard says. “Putting aside my tech head considerations, this room is actually being used largely as big play room for my two young children. There’s nothing better than cozy floors.”

While Millard could have incorporated radiant cooling using Ecowarm’s RadiantBoard, he already committed to an air-to-air heat pump for the space.

“The 2.5 ton Chiltrix would have needed to be upsized by a lot to cool the space. In a future project, I will try using an air-to-air heat pump with Ecowarm RadiantBoard in the ceiling for some cooling plus a chilled water air handler for humidity control,” he adds.

The layout and installation

Ecowarm RadiantBoard staff provided a complete CAD layout that made this a paint by number type project that included the panel locations, panel count, PEX requirements and manifold locations.

Millard is a plumbing and mechanical contractor by trade, so he had Cliff Meehan of Long and Meehan Builders, also of Edgartown, install the new insulated Ecowarm RadiantBoard EPS panels on the addition subfloor to keep heat from escaping to the workshop below.

“The integrated EPS radiant panel spared me the time and expense of insulating under the Subfloor,” Millard says. “While the Ecowarm RadiantBoard EPS is available 1 1/8-inch thick R 2.70 size, we chose the thicker R.5.6 size for this project because of the unconditioned space below.”

Meehan adds, “As a general contractor, I prefer the Ecowarm RadiantBoard solutions. They feature a high-grade plywood substrate that is compatible with all flooring goods we use on our high-end custom homes projects. Plumbers and mechanical guys don’t think about this stuff, but I sure do.”

Meehan notes that using Ecowarm RadiantBoard made the installation easy — without the mess of cement that was previously used.

“It’s a dry installation that goes down fast,” he says. “The 3/4-inch plywood substrate portion of the panel allowed me to glue then nail the hardwood directly to the Ecowarm RadiantBoard for this project.”

Radiant floor and wall

Ecowarm RadiantBoard is a flexible radiant heating tool, allowing installers like Meehan to use different models to create a radiant heating subfloor, radiant wall or radiant celings. “It’s now just part of my radiant problem-solving toolbox. We largely do major remodels of big, custom homes that present challenges we can meet.”

Meehan also appreciates the product’s customization.

“They also make the Ecowarm RadiantBoard EPS in custom thicknesses and R values,” he says. “I have a project coming up over concrete where we are more comfortable with R 11 insulation performance. The factory is working with me. Ecowarm RadiantBoard also features a professional, high impact and high-compression assembly, which is important when I use it over existing concrete floors or in garages.”

The result are in

This past winter, Millard’s 1,500-square-foot addition alone was heated using the 2.5 ton Chiltrix air-to-water heat pump without using the backup electric elements in the buffer tank.

“My large solar electric system was just connected this past December, so I am waiting to see if solar production this summer can help me approach my goal of annual net zero energy,” he says. “Standing by…”