Ambient temperature
The available temperature difference between the coolant and air affects heat transfer. A rating at one ambient temperature cannot simply be reused at another.
Fluid and concentration
Fluid properties influence heat transfer and pressure drop. State the coolant composition and concentration.
Flow and fan conditions
Fluid and air flow affect performance, pressure losses and energy use. Define the conditions associated with the stated duty.
Compare like for like
Compare quotations at the same thermal duty, temperatures, fluid conditions, pressure-drop limits and fan operating basis. Mark calculated performance and measured results separately.