Designing a VRF system for competitive bid is challenging due to each manufacturer’s unique implementation of the VRF system technology. Each has its own set of requirements and restrictions that must be considered. However, if the system is designed solely for a particular manufacturer’s requirements, the design will be hard to bid by others. In particular, the capabilities of the proprietary central controls systems are vastly different. We recently designed a large VRF system that required controls integration with a central BMS, rooftop units, and indoor humidification control by 3rd-party duct humidifiers and humidistats. As we talked with different VRF manufacturers, we learned that it wouldn’t be as simple as we initially thought.
This article will share what we learned by answering a handful of questions related to connection capabilities of three VRF manufacturers to demonstrate the magnitude of difference in their controls platforms. The VRF manufacturers were arbitrarily selected and have been left anonymous in this article. The purpose of this article is not to “rank” the VRF manufacturers, so their position in each question slot has been randomized.