Aaon Inc.’s WH Series horizontal configuration small packaged water-source heat pumps are designed as competitively priced, highly efficient, premium, quality units that are great for retrofit or new construction applications. With Aaon flexibility, the WH Series can also be used in applications that require unique features, including high-efficiency filtration for health care applications, hot gas reheat for humidity control applications, and factory-installed waterside economizers for high-efficiency applications. The company’s focus on serviceability and performance helped the WH Series earn gold in The NEWS’ 2017 Dealer Design Awards HVAC Light Commercial Equipment category.

“We’ve had larger rooftop water-source heat pump products for about 15 years,” said Eric Taylor, marketing manager, Aaon. “A lot of the research that went into those products and the knowledge we’ve gained from them went into the new WH Series. So, you can say we’ve been working toward this for the last 15 years, but we’ve been more focused on the designs for the last five years or so. We saw there was an opportunity out there for a more premium product in the small packaged water-source heat pump market. There was also some demand from our representatives and their customers for a better product.”

The WH Series consists of a lightweight all-aluminum cabinet construction with closed-cell neoprene foam rubber insulation provides a fiber-free airstream. The units also include induction brazed copper piping and stainless steel drain pans. Energy saving features include single-stage and two-step compressors, permanent split capacitor (PSC) or electronically commutated motors (ECM) direct-drive supply fans, and aluminum microchannel air coils with a large face area for improved efficiency and reduced air pressure drop, fan horsepower, refrigerant charge, and unit weight.

“The nice thing about this product in comparison to similar heat pumps is it’s made out of aluminum instead of steel,” said Jim Hennessy, sales engineer, Precision Temperature Control Inc., Bedford, New Hampshire. “The 20 we installed were all hung in the ceiling. And honestly, they’re light, which was the biggest factor on why we chose them. They are significantly lighter — it’s just much easier to work with overhead when they weigh less.”

In addition to the lightweight design, one of the biggest factors that set the WH Series apart is the serviceability, Taylor noted.

“We’ve designed the WH Series to typically be installed in drop ceilings or above a space, and we’ve built in bottom service access,” he said. “With a typical piece of equipment, you may have to physically take the unit down to access some of the components or take it apart. We designed some bottom serviceability into the unit that allows quick and easier service.”

According to Taylor, a large part of the project was spent working directly with one of the manufacturer’s sales representatives to get feedback from their customers on the product design and how to improve it.

“There was a lot of back and forth as far as listening to their feedback and trying to meet their needs,” he said.

Additionally, Aaon is expanding the water-source heat pump product line in capacity, features, and vertical configurations.

“We’re listening to feedback to make the product better and add in features and options we don’t have available today,” Taylor added. “I’m sure there will be more features, like two-step compressors. We’re working on modulation capability on the compressor now for a more part-load efficient unit. And we’re also working on expanding the product line. Currently, the WH Series is available in ½- to 5-ton sizes. We’re working toward expanding it to 15 ton.”


Designed to make replacing packaged rooftop units easy and profitable, York® Direct Fit™ ZQ06 14- SEER packaged cooling and heating units provide 5-ton of cooling with two-stage gas heat or cooling only models. The ZQ06 saves time, money, and materials by fitting directly on pre-existing, competitive curbs without the need for a transition.

Four years of research went into developing the Direct Fit. The first standard-efficiency a/c units were launched in fall 2013, and the manufacturer continued to expand the efficiency offerings to include standard and mid-efficiency units for both air conditioning and heat pumps. The last lines were released in March 2017, according to Laura Meyerrose, commercial product manager, Johnson Controls Inc.

The Direct Fit features quality and application flexibility, which is provided by a dynamically balanced direct-drive outdoor fan and belt-drive indoor fan rated at a quiet 79 dBA. Three static drive options provide airflow versatility up to 2 inches of external static pressure (ESP). Choice of 2- or 4-inch filters that accommodate up to MERV 13 can be easily converted without special tools. To minimize field labor, the thermostatic expansion valve (TXV) and temp sensors come factory-installed. For physical durability, the cabinet uses embossed-top panels for increased structural support and rigidity. To provide outstanding corrosion protection, the powder paint exterior finish is 1,000-hour salt spray rated. The ZQ06 is a member of the Direct Fit Series of direct replacement rooftop units available in 3- to 12.5-ton sizes.

“The Direct Fit has several key competitive advantages, including exact fit on select competitor curbs without an adapter and direct utility matchups; standard Smart Equipment controls; optional industry-leading refrigerant-side fault detection and diagnosis that monitors unit performance and provides detailed alerts that can pinpoint issues and required maintenance; sturdy construction, including embossed panels that prevent sagging and excess vibration seen on similar rooftops; standard low-leak economizers controlled directly by the unit’s Smart Equipment Control; and it is designed, engineered, and assembled in the U.S,” Meyerrose said.


Reznor’s Next Generation Packaged Rooftop unit is made for two markets.

For contractors, the R7TQ, sold under the Mammoth brand, is a high-value, next-generation, direct-fit replacement for today’s popular pre-existing rooftop curbs without the need for curb adapters. For plan and specifying engineers and mechanical contractors, the R7TQ, sold under the Reznor brand, can be configured at the factory in over 750,000-unit configurations, so new construction can get the exact spec units they need delivered to the job site. The units are manufactured using Demand Flow Technology (DFT), an advanced and flexible quality-control manufacturing process. To ensure accuracy, each unit is bar-code verified to the bill-of-material components as it rolls down the line. Research on the unit began in fall 2014.

“The Next-Generation Rooftop was created as a way to get deeper into the light commercial market with a flexible unit that appeals to different customers and their specific needs,” said Dave Garvin, product manager, Nortek Global HVAC. “But we also added many quality features and improvements customers will appreciate. Foam panel construction and hinged panel doors are standard. The 1-inch foam panel wall construction ensures IAQ is fiberglass-free and provides a higher level of efficiency. High-quality hinges eliminate screws on the roof and keep the access doors in place, even in high-wind conditions.”

The Next-Generation Packaged Rooftop unit features electromechanical controls that simplify understanding of unit operation; a terminal strip with plug-in relays that simplifies troubleshooting and allows technicians to see the relay contacts; and hinged access doors with prop rods to hold them open provide easy access to control panel, compressor, blower, and filter with no leaks and no screws to lose.