Carrier Focuses on Efficient HVAC Equipment in a Small Footprint
ATLANTA — At the AHR Expo, Carrier led off its booth display with the 3- to 6-ton WeatherMaker packaged rooftop unit (RTU) with EcoBlue technology, something that Mark Rabbia, product business manager, Carrier Commercial Systems, said sets the tone for Carrier’s upcoming product releases.
“This is going to be the future for us, as we work our way up to the larger sizes,” Rabbia said. “The last three or four years, the government’s been increasing the efficiency levels. As a manufacturer, when it comes time to replace existing units, we don’t want to tell a customer they have to tear up the whole roof to replace that unit … with a unit that has all the right efficiency levels.”
In order to achieve that, the engineering team needed to keep the new, higher-efficiency unit no larger in size than it has been in the past.
“So we have to use technology,” said Rabbia. “And that’s what this unit represents: the infusion of technology that maybe you can’t see, but it’s there, and it’s helping us maintain our footprint.”
Central to the unit and its EcoBlue Technology is the indoor vane axial fan design, which replaces traditional belt drive fans and reduces the number of moving parts by 75 percent.
“Moving parts require maintenance,” Rabbia said. “What we’re trying to do with this product is make it very easy for service folks to not only start up our units and run our units, but service them down the road, should that happen. It really balances what we need from an efficiency perspective, and the price and cost allows us to be very, very competitive.”
Carrier also added a controller that switches the method of changing air speed or how much air is being delivered via a dial, rather than the system of belts and pulleys.
“If the customer says, ‘I want to deliver 1,750 cfm of airflow at 1 inch of static,’ the service contractor installs his volt meter, sets the volt DC, turns the dial to 7.4, and boom, he’s got it,” Rabbia said. “No experimenting in the field, no having to go down the ladder and go to the parts store.”
Similarly, the AquaForce 30XV air-cooled chiller was designed to fit within the same footprint as units built 15 or 20 years ago. A hydronics kit is installed within the unit, with a pump package that goes up to 325 tons.
“You need to have a hydronics system installed to move the water; every chiller does,” said Frank Silva, product manager, air cooled chillers. “If you can have that inside the footprint of your chiller, you save on space, you save on installation costs, customers will not have to deal with all these installation concerns — it’s going to be all built into the unit.”
Like the RTUs with EcoBlue Technology, the 48/50A applied packaged rooftop units use technology to optimize energy. In this case, Carrier added Greenspeed intelligence, which varies the speed of the outdoor fan motor to optimize energy for a 10 to 15 percent increase in part-load efficiency.
“It’s been proven in residential and proven with our packaged chillers, and we’re moving that technology into these applied RTUs,” said Chad Osburn, product manager, rooftops.
In the realm of efficiency, Carrier’s 500- to 800-ton AquaEdge 19DV centrifugal chiller merits a mention in more ways than one. The 19DV chiller on display was equipped with both free cooling and heat recovery capabilities.
“When condenser water is colder than chilled water, we can actually turn the compressor off … and the chiller provides up to 270 tons of capacity with no compressor power,” said Scott McDonough, product manager, water-cooled chillers.
The heat recovery process can also make 120°F hot water. The 19DV utilizes a two stage, back-to-back compressor with refrigerant lubricated ceramic bearings, so there’s no oil management system.
In addition, the 19DV uses the ultra-low GWP refrigerant 1233zd (E) — a refrigerant with a GWP of approximately 1 and an A-1 safety classification. The 19DV at the expo also includes a falling film evaporator, variable orifice and unit-mounted VFD, and was designed for variable- or constant-flow pumping schemes, in either series or parallel arrangements.
“In the past, you had to choose: Do I want a heat recovery chiller or a high efficiency cooling chiller? Now you can have both, all in one machine,” McDonough added.
Carrier’s Aero 39M air handler handles efficiency via R-13 insulation and a tight, minimal deflection casing to maintain a low leak rate. Built since 2001, it was one of the first products on the market with a foam-filled, rather than fiberglass-filled, panel.
“The unit has thermal break, so we have a panel on the inside, an extrusion here approximately 2 inches thick, and then the metal panel on the outside, so there’s no heat transfer from the inside of the unit to the outside,” said Tom Buswell, product manager, air handlers.
The units are 1 percent air leakage maximum, at ±8 inches. In terms of airflow, fresh air is on the bottom in this unit, and return/exhaust air is on the top: It goes through the air exchange wheel, the wheel rotates, and it transfers the energy to the outside air coming into the unit. The unit also has the option of dual direct-drive plenum fans.
“These … allow a contractor to cut their openings in the panel most anywhere they’d like to accommodate the ductwork that they need,” Buswell said. “And the plenum fan is also much quieter in operation than a housed fan.”
New for Carrier, a QR code on the unit label can be scanned with a smartphone to show part numbers, product data, and an installation guide.
“There’s no more writing it down, getting to the parts store, and wondering, ‘Is that an O or is that a zero?’” Buswell said.
Carrier’s booth also included a section highlighting ductless and VRF products, which Nick Conklin, product strategy, ductless and VRF, referred to as one of the fastest growing technologies in the U.S. due to the high efficiency and the flexibility.
“And that’s really the beauty … to ramp down on energy efficiency,” he continued. “The product starts literally at zero and only ramps up to what you really need, instead of putting a 20-ton or a 50-ton or a 100-ton unit on full blast.”
The Infinity ductless system, at 42-SEER and 15-HSPF, comes with built-in occupancy sensing, relative humidity sensing, and built-in Wi-Fi — all ready to go straight out of the box.
“We’re pairing it with furnaces and air handlers, via a 24-V interface that allows the two to communicate and use a standard wall thermostat inside the home,” Conklin said. “The benefit to this packaging is, we’re maintaining the efficiency of the outdoor unit through the proprietary logic we’ve got built in, and we’re giving the indoor side — the furnaces and air handlers — multiple fan speeds to further improve efficiency and comfort.”
Carrier has taken Toshiba-Carrier VRF systems — both the three-pipe heat recovery and the two-pipe heat pump — and paired them with a rooftop fan coil.
“For applications requiring VRF technology, we took Carrier rooftop units, modified the 3-, 4- and 5-ton chassis, removed the compressor and that condenser fan, and turned it into a VRF fan coil,” said Conklin.
Multiple rooftop fan coils can be plugged into one outdoor VRF condensing unit.
It can also be paired with more traditional VRF-style fan coil units.
“The big benefit is, you can keep your piping outside the structure, use the existing rooftop curbs, and upgrade your building’s performance through the variable speed of the VRF systems,” he added.
Publication date: 2/18/2019