Safe Thermostats for More Climate-Friendly Refrigeration

t stat piece on refrigeration and global warming

It is estimated there are over 2.5 million HC refrigerated display cases worldwide in grocery stores alone and 2 billion in household refrigerators and freezers according to analysists. The US is trailing other parts of the world in the transition to alternative hydrocarbons.

Today’s regulatory and legislative requirements continue to push OEM’s to change to non-toxic hydrocarbons in their refrigerating systems. Hydrocarbons (HC’s) present a risk of fire (flame) and explosion hazard if there is a refrigerant leak. The invisible vapor with the closed refrigeration system in not flammable until oxygen is present at the location of the leak or in the location(s) where the HC travels (diffuses) after leaking from the system. If the gas percentage and air mixture is within the upper and lower flammability limits (typically ≥50 grams) the mixture is flammable in the presence of an ignition source.

The most commonly used hydrocarbons are R290 and R600a are compatible with standard oils and materials used with HFC’s.

Thermostats can be charged with hydrocarbon which is a very small amount of gas which is safe. It is always the OEM responsibility to specify and determine the suitability of a particular control.

In this case, whether a complete explosion-proof type thermostat should be used, Selco can produce the NWP series, which is an ignition-protected component for use in refrigeration and air-conditioned equipment. The NWP series is in accordance with IEC 60079-15 standards. The additional costs for HC charge or explosion proof case are minimal but could depend on the application. This change will allow a safe smooth transition away from ozone depleting potential (ODP) and global warming potential (GWP) by using substitutes that offer lower overall risks to human health and environment.

Click here for more details on the NWP Series

Selco obtained this info from multiple sources. References listed at the end.

Keywords

  • HFC’S or HC- (hydrofluorocarbons)– a type of refrigerant gas used in refrigeration and air conditioning equipment to cool and freeze
  • Refrigerant– a chemical that produces a cooling effect while expanding or vaporizing
  • Flammable Refrigerant– a HC that could present a risk of fire or flame which is an explosion hazard if the refrigerant leaks
  • R290– a type of propane, the use of R290 is increasing due to its environmentally friendly impact and excellent thermodynamic performance.
  • R600a– a common refrigerant grade Isobutane
  • Explosion proof thermostat– a thermostat that can be charged with a small amount of HC that is safe
  • ODP– ozone depleting potential
  • GWP– global warming potential

Typical Applications

  • Refrigerators
  • Food service equipment
  • Bar refrigeration
  • Coolers
  • Freezers
  • Merchandisers
  • Prep tables
  • Chillers
  • Reach ins
  • Air conditioning
  • Beverage dispensers
  • Dehumidifiers

References:

Supermarket News (2019, June) Retrieved from https://www.supermarketnews.com/store-design-construction/r290-merchandisers-big-picture

EIA Global, (2020, December) Retrieved from https://eia-global.org/press-releases/20201010-california-approves-groundbreaking-new-climate-regulation

EIA Global, (2020, December) Retrieved from https://eia-global.org/press-releases/20201223-congress-hfc-legislation-kigali

Business Wire, (2021, February) https://www.businesswire.com/news/home/20210215005414/en/Leaking-Havoc-Exposing-Your-Supermarket%E2%80%99s-Invisible-Climate-Pollution

Climate Friendly Supermarkets, (2021, February) Retrieved from https://www.climatefriendlysupermarkets.org/leaking-havoc

We are honored to serve as a manufacturer’s rep for Selco. Selco’s wide range of temperature control products serve a variety of industries including appliance, HVAC, medical, telecommunications, food service, and instrumentation. Products include thermostats, NTC thermistors, thermal cut-offs, thermal protectors, knobs, precision electronic controls, high-bright LED lighting, panel instruments, and photocells.