SAFETY
Water: a safer medium for heat transfer
Hydronic systems rely on heated or chilled water to transport thermal energy throughout a building, either delivering or removing heat from occupied spaces. Water provides a safer means of energy transfer.
An increasingly common alternative to water-based systems is the VRF (variable refrigerant flow) system. In these systems, a great deal of refrigerant is piped throughout the building in extensive, field-assembled circuits. Unfortunately, refrigerant is hazardous and carries ozone-depletion potential.
Refrigerant is almost always necessary in cooling applications, but the dangers that it presents can be reduced or eliminated in three ways:
- Use less of it.
- Concentrate it in mechanical areas, away from building occupants.
- Use only factory-sealed refrigerant circuits.
Hydronic systems check all these boxes, and as a result, contain far less refrigerant than other HVAC systems and utilize it more intelligently. In heating-only hydronic applications, no refrigerant is used at all.
A water leak in a hydronic system is non-hazardous and very easy to locate. On the other hand, a refrigerant leak in a VRF system is potentially hazardous to occupants and extremely hard to locate.
With a natural medium for heat transfer, and piping systems designed to withstand the test of time, hydronic systems are in a class of their own when it comes to occupant safety.
Resources
- EPA Section 608, Stationary Refrigeration and Air Conditioning Information – U.S. Environmental Protection Agency
- Benchmarking Risk by Whole Room Scale Leaks and Ignitions Testing of A2L Refrigerants – Air Conditioning, Heating and Refrigeration Technology Institute (AHRI)
- Applying Refrigerant Codes – HPAC Engineering
- Time to split? Moving away from specifying splits, VRFs and VRVs – Airedale International Air Conditioning Ltd.
- New online training addresses firefighter safety related to flammable refrigerants – UL Firefighter Safety Research Institute (UL FSRI)
