Choosing between thermal fluids and steam is an important decision when it comes to industrial heating systems.
Both heat transfer mediums offer distinct advantages and limitations, and understanding these differences is key to thermal processes being as effective as possible.
This article compares and contrasts these two heat transfer methods for industrial systems.
Operating temperature and pressure characteristics
Steam systems operate under significant pressure to achieve higher temperatures, with saturated steam at 200°C requiring approximately 15-bar of pressure. This pressure requirement increases with temperature, creating mechanical stress on piping and equipment.
In contrast, thermal fluids like Paratherm NF can operate at temperatures up to 630°F (332°C) in unpressurised closed-loop systems.
Paratherm’s heat transfer fluids function effectively across an impressive temperature range from -88°C to +343°C, providing operational flexibility without the safety risks associated with high-pressure steam systems. This difference in operating characteristics makes thermal fluids particularly suitable for applications requiring precise temperature control.
While steam systems experience temperature fluctuations as pressure varies, thermal fluid systems maintain consistent temperatures throughout the circuit. The result is better process control and product quality.
Safety and risk management
Thermal fluid systems are recognised as posing less safety risks in many applications. Steam systems present risks from high-pressure failures, which can result in damage and serious injuries. The rapid expansion of steam during leaks creates additional hazards that require extensive safety protocols and emergency procedures.
Thermal fluid systems eliminate these pressure-related risks while introducing different safety considerations. Modern thermal fluids like Paratherm OR are specifically engineered with oxidation inhibitors to extend fluid lifetime and provide sludge protection. On the other hand, thermal fluids do require attention to fire safety protocols, as most are combustible materials with specific flash and fire points.
Energy efficiency and heat transfer performance
Steam offers excellent heat transfer coefficients due to the latent heat of vaporisation. This makes it highly efficient for applications requiring rapid heating.
However, steam systems suffer from significant energy losses through condensate return, steam traps and distribution piping. The need to continuously treat makeup water and manage condensate adds to operational complexity and energy consumption.
Thermal fluid systems provide superior energy efficiency in many applications, and this is thanks to their closed-loop design. Products like Paratherm NF demonstrate advantageous interaction between paraffinic and naphthenic content, creating high density with low viscosity, which enhances heat transfer efficiency while reducing pumping energy requirements. Because there is no phase change, this eliminates the energy losses associated with condensate handling, and the closed-loop system also minimises heat losses.
Maintenance and operational considerations
Steam systems require extensive maintenance infrastructure, including steam traps, condensate return systems, water treatment facilities and regular inspection of pressure components. The corrosive nature of condensate and the need for continuous water treatment add complexity and ongoing costs.
Thermal fluid systems offer simplified maintenance profiles with fewer components requiring regular attention. High-quality thermal fluids like Paratherm NF demonstrate extended operational life and resist fouling caused by thermal cracking. This extended life span reduces fluid replacement costs and system downtime.
Application-specific advantages
Different industries favour different heat transfer mediums based on specific requirements. Heat transfer fluids find applications in alternative energy, asphalt processing, chemical processing, engineered wood production, extraction sciences, industrial drying, meat and poultry processing, oil and gas and plastics manufacturing.
Food processing industries particularly benefit from thermal fluids due to regulatory compliance capabilities. Paratherm NF has been FDA registered as food-grade since 1989 and is certified kosher and Halal, with NSF HT-1 registration for incidental food contact applications. This certification eliminates concerns about contamination that might occur with steam systems using water treatment chemicals.
Economic analysis
Initial installation costs typically favour steam systems for simple heating applications, as steam generation equipment is well-established and widely available. However, thermal fluid systems often demonstrate superior long-term economics through reduced energy consumption, lower maintenance requirements and extended equipment life.
The economic advantage of thermal fluids is more significant for applications requiring precise temperature control, high-temperature operation or systems with high distribution distances. By eliminating elements such as condensate return systems, steam traps and water treatment facilities, cost savings can be made.
Ultimately, the choice between thermal fluids and steam will always rest with specific application requirements, safety considerations and long-term operational goals. While steam remains ideal for certain applications requiring rapid heating, thermal fluid systems offer advantages in precision heating and processes requiring enhanced safety profiles.
