What is Variable Refrigerant Flow?
- Variable Refrigerant Flow, or VRF technology, is equipment that routes 2 and 3-pipe refrigerant circuits from one outdoor unit to multiple indoor units (or zones) and is capable of providing heating and cooling at the same time as different zones require.
- Unlike traditional refrigerant systems that are either “on” and operating at 100% capacity or “off”, VRF equipment utilizes inverter compressors which provide variable speed operation. Why is this so important? Because your HVAC systems seldom need to provide 100% of the capacity they are designed for.
- VRF systems routinely operate at partial loads in the range of 30 to 70% which provides more consistent indoor temperatures and humidity levels as well as provides energy efficiency.
Because of this part-load capability, VRF systems are as efficient, and often more efficient, than commercial chiller/boiler systems while at the same time offering much greater design flexibility and much more usable square footage.
- Efficient –similar or better than chillers, 180% as efficient as standard splits and RTU’s
- Small space requirements = more livable space.
- Individual room control – indoor fan coils range from ½-ton up to 5-tons and can heat and cool independently (with optional packages).
- Remote control and monitoring via internet.
- Durability – these systems have been outlasting commercial chiller plants.
- Excellent dehumidification – which is great for building preservation.
- Design flexibility – wall mounted, ceiling mounted, concealed non-ducted cassettes fit within acoustical ceiling tiles, and concealed ducted indoor unit types up to 5-ton units.
- Very low maintenance (particularly compared to central plants).
- Modular installation: these systems are great for retrofits, “add-on” tonnage, and phased construction.
- No gas required; all electric. No auxiliary heat strips needed.
- Suitable for a broad geographical range. These systems perform to subzero temp
Why Contractor Selection is Important
The most pronounced disadvantage to VRF technology is that the manufacturer’s do no limit unqualified mechanical contractors from purchasing these systems. To get the efficiency, durability, and superior control these systems provide, the piping systems and control systems must be installed per the manufacturers’ very specific instructions.