What do you get when you combine a top-end restaurant needing a kitchen upgrade with a contractor who specializes in VRF? A VRF-enable air makeup system of course!
Initial design requirements called for 5,800 CFM airflow with a year-round discharge temperature of 70F making it ideal for application of a heat pump.
LG had recently introduced its AHU kit that provided an integration solution for their VRF technology to be used with any manufacturer’s AHU. The adjoining hotel property had approximately twelve existing VRF systems so the owner group was invested in the technology. Moreover, the kitchen ventilation system included an existing variable volume controller which also varies the airflow of the MUA; this served to further solidify the application of VRF due to the infinitely variable capacity control.
O’Dell considered the requirements and worked with both LG and Bousquet to deliver a tailor-made solution.
A Bousquet custom gas fired air makeup was selected with heat capacity to deliver 100% of the load when the VRF system is outside its operational parameters. The unit included Bousquet’s 409SS drum & tube heat exchanger with 21:1 turndown and compatibility with variable airflow. A DX coil was selected with the primary capacity to handle the cooling load. This same coil is also used for heating during the shoulder seasons, providing precise discharge air control. Utilizing both the LG AHU kit and a third-party controller the contractor performed full control integration that operates the VRF as first stage of heat provided that the outdoor temperature meets the minimum requirement. Discharge air temperature is also monitored such that if the VRF cannot meet the target, or should the VRF enter a defrost cycle the gas furnace is automatically activated.
This solution delivered on a number of project initiatives
- Precise year round conditioning of outside air to the kitchen
- Energy efficient cooling & heating
- Reduction in greenhouse gas emissions
- Reliable system operation 365 days/year