With condos came a few new climate-based challenges to property owners, developers, and HVAC professionals.

Individual energy metering became a consideration with new, multifamily dwellings, especially considering that many of the spaces are often unoccupied for months at a time. While this may be true with any multiunit buildings, the northern coast’s dramatic freeze-and-thaw cycles, coupled with year-round high humidity, become an obstacle for air-to-air heat pump technology, which are often high on the list of comfort solutions in condos.

“Keeping condensing units defrosted is the biggest issue here,” said Dale Comeau, general manager of Comeau Refrigeration and Air Conditioning, a five-person company based in Annapolis Royal, on Nova Scotia’s northwestern coast. The firm’s main focus is ductless heating and cooling systems, but it also installs ducted and geothermal equipment and offers commercial refrigeration sales and service.

In the maritime climate, high outdoor humidity exists even below freezing temperatures. Condensing units can quickly become covered with frost, restricting airflow and reducing net heat output.

“I’ve actually had homeowners ask me how often they should expect to defrost their new units,” he continued. “Their concern is based on past experiences or horror stories they’ve heard. So, they’re a bit skeptical when I tell them they shouldn’t ever have to defrost it manually.”

Comeau Refrigeration has a local reputation for making ductless systems work, despite the weather. The company’s accountability ultimately helped land one of the largest single mini-split jobs they’ve completed to date.

Dockside Ductless

In 2011, Provident Developments found Comeau Refrigeration on Fujitsu’s “find a contractor” webpage. After checking the company’s reputation locally, Provident called to explore the possibility of a system for Dockside Waterfront Drive, a recent project in Bedford. Three meetings and one proposal later, plans were set to install multi-zone, high-efficiency ductless heat pumps at the property.

Two towers — 5 and 6 stories tall — include a total of 78 luxury condos overlooking a finger of Halifax Harbor. They offer quiet waterside living just 20 minutes from downtown Dartmouth and Halifax. Comeau’s individual heat pump design trumped Provident’s initial approach, which was based on a large variable refrigerant flow (VRF) system. “Individual metering was probably the biggest consideration for this project,” said David Hilchey, vice president, Provident. “Both the VRF approach and individual unit approach provided that capability. Ultimately, the mini splits provided a more cost-effective solution.”

By the end of the project, a total of 79 Fujitsu RLXFZ units were used for the condo units and one common area. Depending on the floor plans, which range 1,100-2,150 square feet, dual-, tri-, and quad-zone systems were installed for maximum flexibility, comfort, and efficiency.

Inside, wall-mounted evaporators and slim duct evaporators were used. Greentek heat recovery ventilator (HRV) systems were tied into the slim duct units to eliminate redundancy and reduce costs. Comeau collaborated with a sheet metal subcontractor to complete the ventilation system. Provident began selling condos in mid-2013.

Frost-free

To keep units free from frost in Maritime Canada, every detail must be considered during installation, and the selection of proper equipment is a must.

“We began installing ductless equipment in 2000, but we standardized on Fujitsu units about five years ago,” said Comeau. “We’ve consistently found their line of equipment handles our constant freezing and thawing very well. For us, that’s the number one deciding factor.”

In addition to taking the weather in stride, the heat pumps are covered by a five-year parts-and-labor warranty and a seven-year warranty on the compressor. “I really appreciate the support I get from Darcy Campbell, a residential external salesman with Master Group distribution,” said Comeau. “The way they honor warranties is exemplary.”

But, careful installation is equally as important as using the right units.

“If we can shelter the unit from prevailing wind, it helps, but that’s not always an option,” he continued. “Refrigerant charge is the most prevalent issue we come across when servicing incorrectly installed equipment. If the unit is defrosting too often, chances are there’s a leak. A leak-free refrigerant system isn’t an option.”

The condensers at Dockside, which are a mix of 2- and 3-ton units, are each located on decks outside the living space they condition, so disposing of defrost condensate was a challenge. To prevent units from freezing, base pan heaters are installed under each condenser, and condensate lines are piped through the building envelope and terminated in the storm water plumbing.

Old Towns, Old Systems

Single-family residences in Nova Scotia present the same climate-related challenges as condos, but with the added task of maintaining historic integrity.

“Most of Nova Scotia is an architectural museum in its own right,” said Comeau. “We’re constantly playing ‘hide the condenser’ to keep homeowners and historic societies happy. But we do this well because we’re picky by nature.

“In single-family homes, we’re typically installing ductless systems that’ll hold their own at true design conditions, which is 0°F, or minus 18?C,” said Comeau.

“If there’s a backup system, we can shave down the capacity a little,” he added. “Environmental Canada says the Maritime average design is 32?F, but, even with backup heat, we never design for less than 14?F.”

“Technology has evolved, and we know how to handle the climate challenges here, but we’re still dealing with clients adapting to the new systems,” said Comeau. As was the case at Dockside, as many homeowners need help getting over the learning curve that can result from exposure to a completely new technology.

Many of the homes in Nova Scotia use wood as the primary source of heat. Because of this, occupants are accustomed to indoor temps of 80°-85°F through the winter months. They make the switch to a ductless system so they don’t have to cut, split, and stack wood all summer, but are surprised at how much they spend on electric throughout the winter to keep the home at the same temperature.

“Other than wood, it doesn’t matter what fuel source you’re heating with, it’s going to cost you a lot to keep an old house that hot all winter,” said Comeau. “After just one winter, they usually come to love the consistent temperature and hands-free heat. And, they sure do like air conditioning in the summer.”

Information courtesy of Dan Vastyan, an account manager and writer for Common Ground, on behalf of Fujitsu General America Inc. Vastyan writes about HVAC, hydronic, plumbing, mechanical, radiant heat, geothermal, solar, and broad building systems industries. For more information, call 717-664-0535 or email cground2@ptd.net.

Publication date: 5/18/2015

Want more HVAC industry news and information? Join The NEWS on Facebook, Twitter, and LinkedIn today!