P: +1 (800) 875-5285
Mon-Fri, 7:30am-5:30pm CST
F: +1 (800) 408-1100

Variable Refrigerant Flow VRF Systems


Information comparing VRF systems to hydronic.

From: Rick Bostian <Rick.Bostian@waterfurnace.com>
Date: Tue, Feb 14, 2017 at 3:01 PM

I have attached some reading material – one an article by our own Kyle DelPiano and an article which references Kyle’s article from  AMCA International’s High Performance Air Systems group who agrees with us that VRF is misleading the public.


I am not sure the direction you want to take so I won’t load you up with the possibilities.  But there are many. 


The direction we took at AHR is that an EER is a cooling test and an IEER is still just a test of part load capacity for a piece of the system – or as I stated the EER is like the efficiency of an engine without adjustment for the rest of the drivetrain, the car style and function, or where it is driven and the cost of fuel.  We are releasing BEST to address the rest of the story.

The Hydronic advantage is not just about HVAC but interface to the rest of the building like water heating and renewables, and ductwork, and factory-sealed refrigerant circuits.

There is nothing wrong with variable – fans and pumps are variable and have been for a long time, Variable compressors are readily available and in practice for a long time.  But other than VRF there is choice and competition.


The issue is refrigerant in field piping multiplies the refrigerant volume in a building by 3 or 4 or 5 times.  If that is no issue then why regulate and recover refrigerant.  It is  when refrigerants change you will be held hostage by the manufacture of the VRF system you installed.  Every VRF system is proprietary – you cannot mix and match and there is no forward or backward compatibility.   The rest of our industry air or water provide for sustainability through choice – ONLY VRF uses AHRI for marketing only.  When water leaks you fix it, when air leaks you lose efficiency, when refrigerant leaks or has to be removed from a whole building lives are at stake.



I included this screen shot – for you to use if VRF goes off on their part load efficiency.  This is a screen shot from AHRI directory for Daikin – If anyone in the audience knows what an EER is maybe they would wonder how a company can take an EER and turn it into an IEER so high and WHY?   – strictly for manipulating AHRI Certification for the purpose of MARKETING a product.  And that is what ASHRAE members need to know.

Written by Scott Rosenbaum
Posted on
Subscribe for Updates