The pump modules, better known as NEUTON, combine chilled beam pinpoint indoor air comfort temperature and humidity control with energy efficiency. Using NEUTON in Campbell’s two-phase HVAC retrofit saved the school district $147,000 in labor installation costs versus the alternative of variable refrigerant flow (VRF) technology. The chilled beam/Pinnacle combination also saves $33,000 annually versus the school’s former unit ventilator system. The energy savings will lower capital dollars spent on the project by $500,000, which is guaranteed by a performance contract with the Lexington, Kentucky branch of Indianapolis-based, Performance Services Inc. (PSI), an integrated design and delivery engineering contractor that led the project. SEMCO provided 46 NEUTON CCBPMs, 212 IQHC active chilled beams, and two Pinnacle 5,000-cfm DOAS units to meet the school’s heating and cooling demands. PSI’s NEUTON specification enabled the reuse of 100-percent of the existing two-pipe loop’s piping, the pumps, and the relatively new replacement chiller and boiler installed in the 1990’s and 2003, respectively. Another advantage is that NEUTON eliminates the need for heat exchangers.

A NEUTON, which includes a powered integrated direct digital controller (ddc), chilled and hot water connections, valves, variable-speed electronically commutated (EC) motor pumps and smart sensors, is superior in temperature and humidity control to the original unit ventilator design especially during season changes. The plug-and-play NEUTON eliminates the guesswork associated with chilled beam system specification, installation, balancing and commissioning. As with most two-pipe designs, the many wildly fluctuating temperatures of spring and fall days resulted previously with uncomfortable indoor temperatures, because of the extensively long periods required to switch from heating to cooling modes. Conversely, Campbell’s design provides pinpoint tempered conditions within a one-degree tolerance, regardless of the season, because its control is based on outdoor dew point, not temperature. If the OA dewpoint is less than or equal to 45°F, the space latent load is satisfied by the Pinnacles’ ventilation air, which is distributed through each chilled beam and controlled via its respective NEUTON. When the dew point surpasses 45°F, the chiller is needed to maintain space conditions.

INSTALLING AND COMMISSIONING

Chilled beams in school retrofits offer superior air comfort and lower costs compared to its nearest methodology competitor, VRF systems, according to Gary Sprague, PSI’s energy management specialist and Campbell project manager. Furthermore, Clark County School District Superintendent Paul Christy, preferred a hydronic-based system versus VRF systems, because of VRFs potential for refrigeration leaks from line sets and evaporators into classrooms and the environment.

Chilled beams have three times the lifecycle expectancy of VRF technology and lower maintenance costs because there are no fans or condensate drain lines. Donahue Mechanical, Morehead, Ky., the project’s sheet metal and piping contractor, executed PSI’s design of reusing all hydronic trunk lines and the former unit ventilator taps for the first floor, but needed to extend the second floor unit ventilator taps to the ceiling for the NEUTON and chilled beam connections.

Most NEUTONs are mounted above each level’s classroom zone’s 18- inch high T-bar drop ceilings and typically control four ceiling flush-mounted chilled beams ranging from 2 x 2-foot to 2 x 8-foot sizes. Each NEUTON was centrally positioned in each zone to limit chilled beam piping circuitry and allow its front panel to swing down through a removed 2 x 2-foot ceiling tile for easy access.

“Our project is best described as a three-loop system– the original pipe loop from the central plant, the takeoff loop to-and-from each NEUTON, and the loop that connects a series of four to eight chilled beams to its specified with geothermal and Pinnacles in the district’s sustainable award-winning new George Rogers Clark high school, also likes the decibel (dB) reduction of chilled beam induction versus the disruptive operational noise of unit ventilator fans for classroom environments,” said Christy. “The two-pipe conventional unit ventilators that preceded the retrofit were noticeably loud and distracting, whereas now I walk into classrooms with the chilled beams and I can’t hear any sound from the HVAC system.

The new high school’s attendance numbers climbed versus the school it replaced–which Christy partially attributes to the comfortable learning environment created by the HVAC. Likewise, the 7th and 8th grade students that came from two other schools are showing an attendance increase during Campbell’s first year, which Christy attributes partially to improved IAQ.

Rising specified with geothermal and Pinnacles in the district’s sustainable award-winning new George Rogers Clark high school, also likes the decibel (dB) reduction of chilled beam induction versus the disruptive operational noise of unit ventilator fans for classroom environments. “The two-pipe conventional unit ventilators that preceded the retrofit were noticeably loud and distracting, whereas now I walk into classrooms with the chilled beams and I can’t hear any sound from the HVAC system,” said Christy.

The new high school’s attendance numbers climbed versus the school it replaced–which Christy partially attributes to the comfortable learning environment created by the HVAC. Likewise, the 7th and 8th grade students that came from two other schools are showing an attendance increase during Campbell’s first year, which Christy attributes partially to improved IAQ.

Rising attendance generally transcends into more productive learning, which will help maintain Clark County Schools’ standing as one of the top districts in Kentucky.

Publication date: 11/6/2017

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