Advantages and Disavantages of VRF systems in New York City

For the past 10 years, VRF systems have become very popular in New York City for both residential and commercial applications. The main reason for this is the limited physical dimensions that this type of system requires. Let’s revisit the main pros and cons of such systems.
Pros:

1. The location of the outdoor condensing units. They can be placed on a dunnage on the roof but also they can be wall mounted at the exterior wall. This is a huge advantage for small retail/commercial spaces located at the ground floor with no access to the roof.
2. The ability to have several indoor air handling units connected to one outdoor unit. This provides the occupants the capability to individually control the temperature per zone making the building/space more comfortable and efficient.
3.  Great dehumidification capability.
4. Various configurations for the indoor units. They can be wall mounted (not the preferred option for architects), ceiling recessed, floor mounted, etc.
5. Quieter operation, the condensing units are much less noisier that traditional condensing unit of split systems and the indoor air handlers are smaller and quieter than a traditional system.
6. No need for economizer configuration. This save the expensive option of having a large louvers and associated ductwork and dampers for the air intakes to meet this requirement.
7. Of course, let’s don’t forget the obvious reason: heat pump configuration that provides heating and cooling all year round. A step further is to choose the system with energy recovery so that simultaneous heating and cooling can be provided (not much typical for residential and light commercial applications)

 
Cons:

1. Limited static pressure characteristics, in other works no much ductwork can be attached to the indoor units (even to the ones featured as a “high static unit”).
2. For commercial applications, ventilation air needs to be brought by a separate system.
3. There is a limitation on the indoor coil maximum and minimum dry- and wet-bulb temperatures, which makes the units unsuitable for 100 percent outside air applications, especially in hot and humid climates. 
4. Initial cost.
5. Maintenance cost. To serve the system for instance in a typical townhouse can be expensive since there can be 8-10 indoor units.

At the beginning of the project, It is important to have a comprehensive evaluation to determine if the VRF will be a good suit for the project. Clear communication between the owner, architect and MEP engineer must be in place. GCF brings to the table solid expertise to help the involved parties to make the proper decision for the project.