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Best Practices for Designing & Installing VRF Systems in Commercial and Multifamily Applications (Part 1)

With LL97 fines around the corner, building owners and managers are looking to reduce greenhouse gas emissions. To do so, building systems will need to rely on an increasingly green electric grid rather than fossil fuels.

And as we look to electrify our buildings’ heating and cooling systems, Variable Refrigerant Flow (VRF) systems have emerged as one solution. With buildings increasingly turning to this technology, we are sharing our current best practices for designing, installing, and operating VRF systems to help everyone — from design engineers and developers to installers and building operators — learn more about the nuances of VRF.

These best practices are based on manufacturers’ literature, ASHRAE and IECC standards, conversations with field technicians, design engineers, building operators, and manufacturers’ representatives, as well as Steven Winter Associates’ extensive functional testing experience. While the focus is intended to be large VRF systems ( >5 tons), many of the best practices are also applicable to smaller mini-split or multi-split systems.

Common terms used throughout this post are defined for those new to the topic and can be found by scrolling to the bottom of the blog.

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Air-Source Heat Pumps in Homes: Soup to Nuts

As I’ve written in several posts [1], electrification is all the rage. Modern air-source heat pumps (ASHPs) are fantastic technologies, and they can provide reliable, efficient, clean, affordable, and sustainable heating and cooling when done well and in the right application. I worry that these caveats are too often glossed over. I’ve also seen really bad heat pump installations, and I think it’s easier to screw up a heat pump than a boiler or furnace.

ASHPs on the exterior of a home

Three ASHPs at a home

This post is an overview of the process I suggest for good ASHP installations. I’ll be doing a post for each of the steps here, but this first post is an outline of the whole process because I believe the whole process is really important. The focus here is on homes, mainly in colder climates, and I’m not talking about VRF systems. I use the generic second person, so “you”  can refer to different people in different steps.

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