Commercial buildings in the U.S. consume a lot of energy, much of it attributable to their HVAC systems. In fact, some estimates indicate as much as 40 percent of the electricity used in commercial buildings goes to the heating and cooling systems, which is why building owners and managers are taking a closer look at the new crop of energy-efficient heat pumps.
These new heat pumps include the traditional rooftop and split-system variety, as well as geothermal and variable refrigerant flow (VRF) systems. Many include cutting-edge technologies, such as inverter-driven compressors and variable-speed controls, which help improve comfort, increase reliability, and lower energy bills. All these features appeal to those building owners and managers who are looking to curb energy costs without sacrificing comfort.
HEAT PUMP BOOM
The growth in popularity of heat pumps, both residential and commercial, can often be linked to economics, said Brian Wathen, commercial product marketing manager, unitary products group and building efficiency, Johnson Controls Inc. “When energy sources like natural gas or heating oil increase in price, homeowners and building owners tend to look at heat pumps as an economical alternative to more costly fuel prices. It also seems that in regions where heat pumps are a popular choice in residential construction, they are also popular in commercial construction.”
Wathen also attributes the growing interest in heat pumps to increased reliability and improved technology, the latter of which has made products easier to start up, commission, and service than older heat pumps. “The residential and commercial heat pumps of the 1980s and 1990s weren’t as reliable and were considerably more complicated, making contractors reluctant to install them. Now, technologies that include wireless capabilities and better controls have made units easier for contractors to understand, install, and service.”
While the commercial heat pump sector is currently a small portion of the overall market, it is growing, thanks to improvements in efficiency and lower installation costs, said Al Fullerton, product business leader, unitary commercial HVAC, Trane. “We’re continuing to see greater demand for heat pumps in the rooftop market in both standard and high-efficiency options, but the market for water-source heat pumps (WSHPs) is also growing. Net-zero-energy buildings, in particular, are starting to utilize geothermal WSHPs to help increase energy savings.”
Fullerton believes the popularity of heat pumps in the commercial market will continue to grow, especially in regions with favorable climates. He also mentioned building code influences like the International Energy Conservation Code (IECC) are influencing growth. “In regions with harsh winter climates, it’s harder to apply a heat pump in a cost-effective manner because supplemental gas or electric heat is required. While other traditional options typically offer a better payback, it is application-specific, and the design and construction of the building are contributing factors.”
Even though heat pumps have traditionally been more popular in warmer areas where cooling is the predominant requirement, that scenario is changing, said Chris Bellshaw, director of VRV products at Daikin. “It was traditionally understood that heat pump heating performance fell quickly as temperatures approached freezing. But, heat pump technology has improved significantly over the past several years, not only in providing higher heating capacities, but, even more importantly, by providing strong performance at levels well below freezing.”
The demand for commercial heat pumps is also being driven by economic growth, which, in turn, is driving the demand for new construction, said Bellshaw. “In existing buildings where gas is already available — most commonly in the northern states and Canada — replacement of existing units will most likely be another natural-gas-fired unit. New construction, however, is moving more toward the elimination of fossil fuels, and, due to improved heat pump technology, applications in colder climates are now commonplace.”
The commercial heat pump market is also growing because of the strong desire in different climates to reduce the electric demand during the cooler or cold months, said Mike Ray, director of commercial rooftop units, Lennox Intl. Inc. “On buildings using cooling rooftops [electric/electric] or split systems with electric heat, the heater provides $1 worth of heat for every $1 of electricity consumed. If the same building used a heat pump, the heat pump would provide two to three times more efficiency in heating when compared to the cooling system with electric heat.”
For this energy-efficient reason, Lennox expects to see commercial heat pump sales increase over the next few years. “There are some locations that require the first stage of heating to be supplied by something other than an electric resistance heater, and the heat pump is an excellent product to meet the criteria,” said Ray. “In this case, the heat pump could supply the first stage of heat and then be backed up by a resistance heater [as supplemental heat]. There are also opportunities for a mixture of heat pumps and gas/electric systems on a building.”
Manufacturers like Trane offer a wide array of commercial heat pump options, including split systems and packaged rooftop units (RTUs) that range in size from 3 to 20 ton. “The split systems and packaged RTUs meet ASHRAE 90.1-2010 standards. The packaged RTUs are fully configurable and come standard with Trane engineered ReliaTel™ microprocessor controls,” said Fullerton.
Trane also offers WSHPs from 0.5 to 25 ton, including rooftop WSHPs from 3 to 25 ton. Multiple efficiency ratings in this line are available, including units that utilize highly efficient two-stage compressors and variable-speed compressors. BACnet controllers with wireless communication and wireless room sensors are also options for the WSHP line, noted Fullerton.
Lennox offers packaged, split-system, and ductless commercial heat pumps. “We are particularly excited about our VRF family, which is the newest addition to our heat pump offerings,” said Ray. “The new line of VRF heat pump and heat recovery units are available in 3- to 36-ton sizes and feature some of the highest efficiency ratings available. Lennox VRF systems also bundle with our packaged rooftops to offer a customized solution to address specific customer applications.”
Lennox’s packaged heat pumps are available in sizes ranging 2-20 ton and include numerous serviceability features, such as isolated compressors and a slide-out blower, said Ray. “The isolated compressors allow service technicians easy access to the refrigeration system and the ability to quickly determine if the system is charged appropriately. The slide-out blower allows a single service technician to access the belt [on belt-drive models], the motor, and blower housing.”
Johnson Control’s commercial heat pumps, including rooftop units, commercial split systems, and ductless systems, are available in capacities ranging 3 to 25 ton in standard efficiencies. “Our units provide the advanced, user-friendly Simplicity Smart Equipment control that offers wireless or Internet connectivity to a single unit or an entire series of units,” said Wathen. “Our commercial heat pumps operate with a standard thermostat commonly used with cooling units with gas or electric heat, so a single thermostat will cover all of these applications.”
Johnson Control’s commercial split-system heat pumps are available with factory-installed 2-inch MERV-8 or 4-inch MERV-14 filters, eliminating the need to install filters in the field. “However, contractors who order units with 2-inch filters have the option of converting them in the field to 4-inch filters, allowing the contractor to upsell, profit, and provide the customer a wide array of filter options,” noted Wathen.
A new entry into the commercial heat pump market is Yanmar Energy Systems’ gas-driven VRF system, which will be available to ship in February 2016 in sizes ranging 8-14 ton. This new system utilizes natural gas as the driver for the compressor instead of electricity. “Our cost-saving configuration options allow for individual control of up to 32 zones on one piping network,” said Chris Dockery, sales and applications engineer, energy systems division, Yanmar America. “This means individual employees can manage their own thermostat comfort levels and unoccupied areas can have their own appropriate temperature settings, too.”
Yanmar’s VRF system allows users to create zoned comfort depending on the location and needs of a building’s occupants, said Dockery. “Heating and cooling only occupied spaces at the levels needed leads to cost, energy, and green savings. And, with 2,000 feet of maximum piping, our units can accommodate large and small structures.”
Daikin offers both VRV products as well as packaged rooftop equipment with heat pump capabilities. Ducted split systems are available in sizes ranging 3-10 ton, and packaged heat pump systems are available in sizes ranging 3-12.5 ton; VRV products are available in air-cooled or water-cooled configurations and heat pump or heat-recovery systems in sizes ranging 3-38 ton.
“In addition to VRV heat pumps, which provide either heating or cooling, our VRV heat-recovery systems have the ability to simultaneously heat and cool from the same outdoor condenser units,” said Bellshaw. “Progressive contractors looking for ways to differentiate themselves from their competition are using these VRV products to grow their businesses.”
Regardless of the type of heat pump system chosen, building owners and managers are sure to see numerous advantages from installing this energy-efficient technology.
“Building owners who install heat pumps will appreciate the benefits of energy savings, lower utility bills, and affordable comfort,” said Wathen. “If it’s applied properly, there really are no drawbacks to a heat pump.”
Publication date: 10/05/2015