In my first blog on Common VRF (Variable Refrigerant Flow) Installation Issues I focused on issues during mechanical and hardware installation that typically lead problems during startup and pre-functional checkout commissioning. This blog will focus on controls issues identified during commissioning design review which usually lead to issues during start up if not addressed up front during design. As mentioned in the previous article, VRF systems can allow for better comfort and overall satisfaction, but if not properly programmed for the owner’s specific application, can lead to numerous complaints during the first year of occupancy.
5 min read
With the current COVID-19 global crisis, organizations all over the country are actively seeking ways to continue to provide the same level of services to their customers while keeping their employees safe. Cx Associates is known for its rigorous standards in the commissioning process, but a large portion of our work is contingent on our ability to be on construction sites, working with contractors to verify the installation and functionality of equipment. With Vermont’s order that all non-essential employees work from home, and with Cx Associates’ commitment to both keep our employees safe and prevent us from potentially spreading the virus on construction sites, we needed to quickly find a way to provide our on-site services remotely for the essential construction work that continues to move forward in a way that still matches our high standards. This blog discusses our approach to remote site work and how we're continuing to serve our clients while safely social distancing from our home offices.
3 min read
After an early morning departure and a snowy drive, my colleague and I arrived onsite to test, among other equipment, a packaged rooftop air handling unit with factory controls. At first, the unit appeared to check all our boxes, but as we dug into the details, it became clear that this would be a very expensive heating system to operate. This blog entry is about factory controls and the importance of getting into the weeds to identify issues like the one we found with this rooftop air handling unit.
3 min read
A large healthcare client of ours recently opened a brand new USP 800 compliant compounding pharmacy, which we commissioned. We collaborated with the engineering team and the hospital during the design phase to help ensure prior issues weren’t repeated, and the hospital’s concerns were thoroughly articulated and addressed. At the conclusion of the design phase, the team was confident that the design direction was solid and would give the hospital what they were looking for.
Topics: Healthcare commissioning HVAC USP 800
4 min read
The ground source heat pump is a wonderful technology that will be vital in achieving energy efficiency goals this century. This technology isn’t new, but it is beginning to become more accepted as a viable solution for large scale, high efficiency HVAC performance. There are two main types of ground source heat pump systems: those that are “Ground Water” (also called Open Loop) and those that are “Ground-Coupled” (also called Closed Loop), see Figure 1 below. In either case, the water from the ground is pumped to a heat pump, where heat is either extracted out of or rejected into the ground and moved into or out of the conditioned space.
Topics: commissioning HVAC Heat Pumps
2 min read
Sometimes certain parts of the commissioning and retrocommissioning process can seem trivial to both the contractor and the commissioning agent. Of course, the process involves some important and significant checks, such as ensuring the piping design detail matches the as-built piping, and that the specified ductwork sizes match the as-built ductwork size. But the commissioning process also deals with some of the finer details that may not seem as consequential or that have already been checked by multiple parties. So, why would the commissioning agent also need to check it again? In this post I am providing a couple examples of real-world commissioning issues that we’ve found. Each is an excellent reminder of why the seemingly minor commissioning verification steps are still required and important, even though they may seem inconsequential.