CHICAGO — Rooftop heating and cooling equipment is a well-established and widely used technology, but that doesn’t mean the sector is standing still. Rooftop units, like most HVAC equipment, are constantly evolving to be more reliable, more efficient, and easier to control than ever before. 

Sized for Smaller Applications

Cambridge Engineering Inc. introduced the Cambridge SA-Series of Blow-Thru^® direct gas-fired space heaters at the show. The new line uses the same technology as the larger, high-efficiency Cambridge S-Series, but is sized for smaller applications. Utilizing 100 percent outside air for efficient, direct gas-fired heating, these heaters employ a proprietary stainless steel burner mounted downstream of the blower. The high-velocity blower achieves a 10:1 induction mixing ratio that minimizes stratification and increases throw. The SA-Series achieves 100 percent combustion efficiency and provides 160°F maximum allowable output temperatures. The units can be mounted thru-wall, under roof, or on a rooftop.

“Customers are looking for energy-efficient technologies,” said Randy Niederer, director of marketing, Cambridge Engineering. “They’re going to their contractors and saying, ‘I’m tired of these high fuel bills to heat our spaces in the wintertime — what’s out there?’ That’s where our equipment comes into play.”

The new construction market for warehouse space is in the best shape it’s been in the past 15-20 years, he said, which bodes well for the rooftop equipment and space heater sectors.

Lennox Intl. Inc. showcased its Energence high-efficiency rooftop units, which are available in 7.5-, 10-, and 12-ton capacities. They feature the company’s DirectPlus blower, Advanced Cooling System, and Prodigy controller, as well as variable-speed outdoor fan motors. Energence units achieve IEERs up to 21.5 and EERs up to 13.9.

In addition, the company’s variable refrigerant flow (VRF) product line offers inverter-driven compressor heat pump and 6- to 30-ton heat recovery systems. The units achieve IEER ratings up to 24.0 and simultaneous cooling and heating efficiency ratings up to 27.2.

“The VRF units meet the demand for customized comfort control,” said Mike Ray, senior product manager, commercial rooftops, Lennox Commercial. “They allow for an individual air handler in each office and offer simultaneous heating and cooling, so each individual can define the level of comfort he or she wants in his or her space. They also provide flexibility for the building owner. The systems can be rearranged as tenants come and go by simply adjusting the refrigerant piping, eliminating the need to make significant changes to the ductwork or the building.”

Large and in Charge

The rooftop replacement market continues to be one of the largest in the entire commercial market, and Daikin Applied has zeroed in on this market segment through its 3- to 20-ton light commercial DC Series rooftop line.

“Daikin’s recent effort to gain market share in this highly competitive market has been a shift to capitalize on our core competency of variable refrigerant volume (VRV) products,” said Kelly Hearnsberger, vice president of product marketing, Daikin. “Daikin invented the VRV product in 1982 and is committed to manufacturing VRF/VRV products in North America. Commercial customers now have a wider assortment of product options to fulfill many installation challenges, whether the solution is a commercial packaged product or VRV system.”

Daikin Applied also made news at this year’s AHR Expo with the introduction of its intelligent rooftop units based on the HVAC Internet of Things (IoT). According to the company, the new Intelligent Equipment platform enables building owners to harness large volumes of data for analysis, moving the industry toward intelligent building systems that intuitively know what building occupants need in terms of comfort, service, and efficiency.

The demand for the use of ammonia and other natural refrigerants is on the rise, but changes in local and federal regulations continue to impact owners of ammonia refrigeration systems.

Petra Engineering Industries Co. displayed its 100 percent outside air package units with water-cooled condensers. The units are available in capacities ranging 45-140 ton. According to the company, “It is becoming increasingly important to create a whole set of solutions for 100 percent outside air units, where all accessories can be included, furnished, and controlled for optimum performance and quality in a single-piece unit.”

Bryan Ware, portfolio leader – Precedent and Voyager II, Trane Commercial HVAC North America, said building owners and facility managers are seeking premium products to operate their structures as efficiently as possible.

“To get to the efficiency levels and payback times that building owners are seeking, we need to employ features, such as variable-speed drives, blowers, and compressors, along with pretty sophisticated controls,” he said.

Trane’s Precedent™ light commercial rooftop units are available with high-efficiency options such as Trane eFlex™ variable-speed compressors and fans that are designed to precisely match output to the cooling demands
of the space.

Other trends cited by Ware include increased demand in both the replacement and new construction markets. Following the economic downturn of 2008/2009, many building owners began focusing on maintaining older equipment, and are now looking at replacing equipment that has served them for 15 years or longer. In addition, “it’s encouraging to see the new construction market coming back,” Ware said, noting that demand in the new construction market recently has begun to rival that of the replacement market.

Regulatory Response

“System owners are looking for product solutions that address the regulatory pressure and enable and empower the continued use of ammonia at their facilities,” said Kurt Liebendorfer, vice president, Evapco Inc. “This is particularly true in the refrigerated warehouse market where owners are advocating for low-charge packaged ammonia systems that are easy to install (including startup) and provide safe, reliable, and efficient operation.”

Evapco’s Evapcold Low Charge Refrigeration (LCR) product line consists of factory-assembled, self-contained ammonia refrigeration rooftop systems designed to ship in one- or two-piece modules.

“Evapcold enables engineers to apply cost-effective ammonia refrigeration systems on retrofit applications, building expansions, and new facilities with a fraction of the refrigerant charge associated with conventional field-built systems,” Liebendorfer said.

Customers in Control

Brian Wathen, commercial marketing manager, Johnson Controls Unitary Products Group, pointed out that in this wireless, connected world, people have come to expect instantaneous results. For example, electronic devices and appliances are not only expected to operate properly, but also to provide instant feedback when they self-detect a malfunction.

“The same can be said for commercial packaged heating and cooling equipment,” Wathen said. “The rooftops of 2015 and beyond will be equipped with components and controls that protect the equipment, provide instant feedback on operating conditions, enunciate potential problems before they occur, and aid the technician during equipment startup and troubleshooting. Less time on the job equals higher profits.”

To that end, Johnson Controls is bringing Simplicity® Smart Equipment (SE) controls to its York® brand of commercial packaged and split-system products. Soon to be standard on all 3- to 40-ton packaged units, the updated Simplicity SE controls are designed to make equipment easier to install, operate, and service, and to provide information that ensures systems are performing to specifications.

An easy-to-read, built-in LCD display and navigation joystick provides quick access to menus displaying unit status; options; current function; supply, return, and outdoor air temperatures; fault codes; and other information. In addition, an optional wireless mobile access portal or hardwired networking capability allows several users access to one or many units using any device with Wi-Fi capability and a Web browser. Operational and energy-use data, set points, schedules, and diagnostic data can be accessed directly from a smartphone, tablet, laptop, or on-site personal computer. Simplicity SE controls can be configured for use with a standard thermostat, zone sensor, or multiple building automation system communication protocol.

Ray Schaffart, marketing and sales support manager, Modine Mfg. Co., said the company’s Atherion commercial packaged ventilation line, which features eight models ranging 7-30 ton in size, helps contractors meet customers’ needs and keeps them ahead of the curve.

Schaffart acknowledged a growing awareness industrywide of high-efficiency, gas-fired-heating rooftop ventilation systems.

“For years, the focus on rooftop efficiency was predominantly on cooling, since the heating side was maxed out,” Schaffart said. “That’s no longer the case. Although it has taken a few years, awareness is definitely picking up from design/build contractors and engineers to include this option in their specs.”

Additionally, he said: “Installing contractors want a system that has easy access to critical components, especially the controls.” Modine engineers its own controls, which allows the company to “control the controls,” he said. “They aren’t outsourced to a third party. This makes maintenance and service much easier.”

Finally, Schaffart anticipates a growing number of rooftop systems being paired with VRF cassettes or chilled beams. The rooftop unit brings in the outside air to meet necessary requirements, heats or cools it just enough to take the chill and/or humidity out of it, and sends that air to a smaller system that adds the comfort element to the air, he said.

Publication date: 2/23/2015

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