As a consulting engineering firm, we are always looking for new technologies to increase the efficiencies of the HVAC systems we design. Doing this allows us to offer our clients the most up to date products to help them evaluate the right systems for their project.
Over the past two decades, variable refrigerant flow (VRF) has become a mainstream HVAC system for multiple applications and can provide one of the highest efficiencies on the market. Here at Baird, Hampton & Brown (BHB), we have seen the request for VRF increase year over year to the point that VRF has become a large part of what we do. Due to this, we have been looking for ways to improve its already high efficiency.
We had the opportunity to incorporate LG’s refrigerant desuperheater into a VRF system for Texas Masonic Retirement Community (TMRC) in Arlington, Texas. LG manufactures a refrigerant-to-water heat exchanger they call their Hydro Kit system, which takes the heat from the building when the HVAC system is in cooling mode and rejects that heat into the building hot water system instead of rejecting it to the atmosphere through the outdoor heat pump.
The project for TMRC involved the addition of a four-story building that comprised of offices, conference spaces, and a museum on the first floor; then three floors of apartments above totaling 36 apartments. Five tankless water heaters and a storage tank were designed for the primary hot water supply to the facility. We approached TMRC with both VRF and the Hydro Kit system for this project as a more efficient system than the chilled/heating water system that we had designed for them a decade ago on their previous apartment building.
The Hydro Kit system allowed us to supplement the tankless water heating system and allowed the system during cooling operation to heat the buildings 384-gallon hot water loop from the VRF system instead of the tankless water heaters. Eight LG Hydro Kit units were designed – two paired per VRF system (refer to photo). The heated water from the Hydro Kits is piped to a water-to-water plate heat exchanger that transfers the heat into the domestic water loop and storage tank. The Hydro Kit system was set to maintain 126°F water leaving the plate heat exchanger to the storage tank. Upon completion of the project, six of the eight Hydro Kits were able to raise the domestic hot water loop temperature from 106°F to 120°F within nine minutes and maintain the loop temperature with the building partially occupied.
Given the data and performance of the Hydro Kit system at the TMRC project, BHB is excited to implement it as an addition to other VRF designs. Projects that best fit this mold would be ones that have a consistent hot water demand all year. We anticipate multi-family or mixed-use developments that plan to utilize a central hot water loop, restaurants, schools, and office buildings, as the first group of projects to be able to take advantage of the Hydro Kit system. If you are interested in learning more on VRF and the Hydro Kit system, please contact Gibran Michel at firstname.lastname@example.org.
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