Toward the end of the 19th century, you could find asbestos almost everywhere in building construction. What does this have to do with building materials today?
Toward the end of the 19th century, you could find asbestos almost everywhere in building construction. Because it was malleable and resistant to heat, chemicals and water, it was a preferred choice for building materials as it offered binding and strengthening capabilities. In the late 1900s, asbestos was so widely used that women and children helped prepare it while men extracted it from the mines.
Until at least 1980, asbestos was still used in the spray applied to textured ceilings until 1989 when the U.S. EPA restricted it for building materials. This was mainly because it caused lung-related issues such as pleural disease and certain types of cancers, including lung cancer and mesothelioma. In Canada, the use of asbestos is banned.
Another popular heating and cooling system on the market today not only has the potential to impact health like asbestos but has also been found to contribute to global warming.
Variable Refrigerant Flow (VRF) systems use refrigerants that have already been banned in the U.S. and abroad, including the commonly used R-410a (phaseout beginning January 2023) which replaced the R-22 refrigerant, which the U.S. EPA banned on Jan. 1, 2010.
This is a part of a phase-out of all hydrofluorocarbons (HFCS) known to destroy the ozone layer and is part of the Montreal Protocol, a collaborative, international effort to regulate and phase out ozone-depleting substances.
There are a couple of issues with these refrigerants, but let’s start with health and safety. The most significant potential health impact associated with R-410a happens during a leak in the piping and gas accumulates in a space. R-410a is heavier than air, which will sink and get in the lower portions of the room near the floor.
If a leak occurs, people in the room will likely experience difficulty breathing or suffocation, particularly in environments with little to no ventilation. The risk increases in facilities like an elementary school where lungs are still developing or an assisted living facility where high-risk patients live. Some refrigerants are flammable, so leaks may also present the risk of combustion.
To help protect occupants, ANSI/ASHRAE standards 15 and 34 define specific refrigerant concentration limits (RCLs) based on pounds of refrigerant per thousand cubic feet of interior volume, beyond which acute toxicity is expected. Because of this, VRF Systems make the most effective solution in a small building where the total volume of refrigerant is minimized.
There are also environmental concerns with R-410a. Starting in January 2022, R-410a already began its phase-down, and production of HFC has been reduced by 10 percent. According to ACHR News, we can anticipate the next steep cut in 2024 when manufacturers must reduce production by 60 percent.
Much of this is being driven by the Kigali Amendment, an amendment to the Montreal Protocol that specifies specific substances that deplete the ozone layer—of which, R-410a is one. Ultimately, this refrigerant is shown to have a significant environmental impact.
One of the biggest benefits engineers tout is the lower cost of VRF systems. And it’s true if you look at the upfront costs associated with it, along with the turnkey installation provided by manufacturers. There’s little wonder why so many engineers implement these systems into their projects.
It’s essential to dig deeper and go beyond the hype. VRF might be cheaper at first, but if you look at the cost of the system over its lifetime, you’ll find prices rise significantly over a hydronic system.
In a “Comparative Analysis of the VRF System and Conventional HVAC Systems, Focused on Life-Cycle Cost,” researcher Jaesuk Park shows that VRF systems cost between $14.90/ft² and $34/ft² for schools and apartment buildings, respectively. Comparatively, traditional hydronic systems range from $11.90/ft² to $31/ft² for the same installation types (Park, 2013).
But what are some of the specific reasons they are more expensive? Here are three primary reasons:
1: Material Costs: VRF Systems require copper piping that must meet a specific grade because of the high fluid pressures and the temperature of the R-410A fluid. ASTM B280 rated copper costs $346.12 for 50 feet of 7/8-inch tubing whereas 60 feet of 2 1/2-inch Schedule 40 carbon steel piping (typically used for hydronic heating applications) cost only $22.80 for the same amount.
2: Labor Costs: Because of the potential hazards associated with VRF systems, installers must be qualified to work with refrigerants as well as relevant ASHRAE codes. Ultimately, installing a VRF system means that not just any HVAC person can provide maintenance on the system—it’ll require a specific person to assist.
3: Proprietary Controls: Where many hydronic systems can work with interchangeable components such as thermostats, VRF systems specify strictly what features can be used. If in a few years one component fails, a building owner might have to change the entire system. These controls can be higher in cost to replace.
One of the most essential features of hydronic systems is their future-proof compatibility. A fan coil, chiller or pump can be replaced anytime by any product from any manufacturer provided they meet the performance specs.
4: Energy Consumption: A study by the Hydronic Industry Alliance compared VRF systems with Hydronics, installed in the same building, and found that “On an annualized basis, the VRF system had an energy consumption 57% higher in 2010 than the hydronic system, 84% higher in 2011 and 61% higher in 2012.”
In operations since the end of the 14th century, hydronic heating systems have been around for hundreds of years and will continue to provide an efficient, safe, and low-cost alternative to newer VRF Systems.
It’s easy to be misled by manufacturer claims. When comparing the two types of systems, look beyond marketing collateral and find reliable studies and information sources. The long-term health of people and the earth depend on it.
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