I've had lots of opportunities to review plans for pending hydronic heating systems. I've also been on "forensic" visits to sites with improperly performing systems. Of the two, I much prefer plan review over forensics.
Although the market for gas-fired boilers continues to track toward those that can modulate and operate with sustained flue gas condensation, conventional boilers (e.g., those not designed to operate with sustained flue gas condensation) still represent a significant portion of the market.
With a considerable volume of contradictory information in circulation regarding the application of different technologies for HVAC systems, this article seeks to explain some of the technical aspects of variable refrigerant flow (VRF) systems, and offer comparisons on the basis of cost and performance to more standard hydronic systems.