VRF/VRV Design w/ Jordan Cummings

A VRF/VRV system works a bit like a hydronics system, but it provides hot or cold air to various zones in a space, not water. The key to having a reliable and long-lasting VRF system is a good installation. Proper maintenance practices, including pulling deep vacuums for dehydration, will also improve the performance and life of a VRF system.

When you choose a system to install, you have to determine if you want a heat pump or heat recovery system. Occupant type will play a major role in that equipment selection. Budget is also a variable, but it is typically less of a concern than occupant type and building purpose.

Some VRF/VRV systems that have been primarily designed for cooling may need to provide heating in low-ambient conditions. In many cases, these will close fresh-air dampers and recirculate discharge gas. Some units may even have auxiliary heat or be backed up by other heating equipment. Defrost is also something you'll need to consider in low-ambient applications.

Sizing is another important part of VRF/VRV selection and design. Consider nominal capacity but don't accept it as a hard and fast value. Keep your design conditions in mind; which temperatures and humidity percentages are you trying to maintain? What is the outdoor air temperature? Also, think about the piping total equivalent length and the estimated total distance between the outdoor unit and the farthest indoor unit.

Jordan and Bryan also discuss:

• Buildings with cooling towers and boilers
• SEER vs. IER
• Aurora VRV equipment and technology
• Connection ratio
• Air handler unit and branch box selection
• Control boxes and accessory selection
• Discharge air control
• Condensate control
• Maintenance concerns for VRF/VRV systems
• Indoor unit turn-down

Learn more about Refrigeration Technologies HERE.