Eden Avenue Grill, a restaurant serving up classic food in Edina, Minn., had an outdoor patio for customers to dine on, but with Minnesota’s cold fall and spring seasons and downright frigid winters, the space was unusable most of the year. To design a consistently usable space and to expand available seating, the restaurant chose to remodel the large patio into a four-season room with a retractable glass ceiling and glass walls. The goal was to allow for the outdoor seating experience in the summer using the retractable roof, while creating a space that was still functional during the winter and cooler months.
“The retractable roof exceeded our expectations [to create an outdoor space during the summer], but obviously a big concern with a glass enclosure is warmth when it is cooler,” owner Ken Johnson recalled. “One of our biggest concerns was that we wanted to use the room 365 days a year. We didn’t want to shut it down on cold days.”
While having so much glass was beautiful, the original remodeling plans did not account for the heat loss it would allow. The planned overhead ceiling heaters were unable to overcome it and successfully heat the room. Without solving the problem of the excessive heat loss, the room would remain too cold for customers to enjoy, realizing Johnson’s fears of not being able to consistently utilize the space.
Midway through the failing remodel, Tom Gonyer, a general contractor for New World Builders, Plymouth, Minn., with 40 years of experience, stepped in to tackle the heat issue along with several other remodeling problems for Johnson, who is also Gonyer’s brother-in-law.
“There were a lot of failings by the original team tackling the remodel, among them a serious heat loss deficiency that would make the room intolerably cold for any customers,” Gonyer recalled. The remodel had included overhead ceiling heaters, but while the overhead heaters generated 80,000 BTUs of heat, the room lost 100,000 BTUs due to all the glass.
“We started out in the red right way,” Gonyer described. “The heat from overhead heaters goes up and out the glass unless you are standing right underneath them, so it really only warms the top of your head without creating true heat in the room.”
Since Johnson was committed to the overhead ceiling heaters, which had already been installed, additional heating was needed to make the room functional. He suggested in-floor heating with water pipes, but the old contractors had already laid new cement slab flooring eliminating that option.
“Because we already had a cement slab in place, we couldn’t do in-floor water heating, but I knew that a system from WarmlyYours would allow us the opportunity to install electric floor heating in the space and create heat effectively,” Gonyer recalled.
The radiant heat would keep the customers comfortable without continuously escaping out the glass.
Mary Godawa, account manager at WarmlyYours, helped plan the installation. She recalls that a big key to the installation’s success was the decision to include CeraZorb®, a synthetic cork underlayment, beneath the electric heating mats before installing a tile floor on top. CeraZorb®, which is available in 4 x 2 sheets that cover eight square feet, is always recommended when installing TempZone™ floor heating systems over a concrete slab, such as the one at Eden Avenue Grill. The cork underlayment creates a thermal break above the slab and increases the energy efficiency of the system.
The CeraZorb® made a big difference in the amount of heat the Eden Avenue Grill was able to capture, Godawa said. Just as the glass allowed heat loss overhead, the large cement slab could allow heat loss from below, but by insulating the slab, the heat created for the room by the electric heating mats was maximized.
Choosing to install CeraZorb®, while an extra cost, made a big difference in the amount of heat the system was able to produce and “played a role in the customer’s happy result,” Godawa added.
Godawa also recommended designing the system to include three power modules and one master thermostat since the space was more than 560 square feet.
When you are using a 240-volt circuit to heat surface areas greater than approximately 200 square feet, a single thermostat can’t handle it, but we can accommodate that by using a master thermostat and power module relays, in this case, three. All the power modules are “linked” with the master thermostat that controls temperature settings and programming for the entire floor. Each additional power module provides an additional 15 amps of service and up to 10 power modules can be added to each master thermostat. Each section talks to the thermostat and requests to be turned on or off, but the restaurant has the convenience of controlling everything with a single thermostat.
After the CeraZorb® was laid, the TempZone™ floor heating system was installed. Then the floor was tiled with large 18” x 18” square, ceramic, brown tile, finishing off the room.
With the careful planning, the space turned out even better than expected. With the WarmlyYours in-floor heating complimented by the overhead ceiling heaters and a fireplace, the space is truly comfortable, Gonyer reported. In fact, “it may even be more comfortable than the main restaurant during the winter!” he added.
Customers are happy, Johnson shared. “They were initially concerned about the warmth of the room. But so far, they have been pleasantly surprised. In-floor heating is a superior way to heat. It’s more even [heat] and works!”
Radiant heating enabled the successful switch from a largely unusable space, to a memorable, comfortable location that customers will come back to again and again throughout the year.
TempZone™ Flex Roll 240V 3’ x 44’ (44-15E-240)
TempZone™ Flex Roll 240V 3’ x 71’ roll (71-15E-240)
CeraZorb® Insulating Synthetic Cork Underlayment (48" x 24" x 5mm) (CZRG-SH5MM-24X48)
Floor Sensor (SENSOR2)
Thermostat Master 12Vdc (TH115-AF-12VDC)
Power Module Dual Voltage with GFCI 5mA (CT230-GA)