Freeze Protection

Reference data and engineering information about freeze protection for hvac systems applications.

freezeprotection

Overview

Engineering reference data for Freeze Protection in HVAC systems.

Key Formulas

Sensible Heat

$Q = \dot{m} c_p \Delta T$

Heat causing temperature change.

Latent Heat

$Q = \dot{m} h_{fg} \Delta\omega$

Heat causing moisture change.

COP (Cooling)

$COP = Q_c / W$

Coefficient of performance.

Variables

Symbol	Description	Unit
$Q$	Heat transfer	W
$\dot{m}$	Mass flow rate	kg/s
$c_p$	Specific heat of air	J/(kg·K)
$\Delta T$	Temperature difference	K

Comparison of Antifreeze Fluids

Different antifreezes offer varying trade-offs in performance, safety, and cost for freeze-protecting water-based heat transfer fluids.

4 rows

Comparison of typical antifreeze fluid properties for freeze protection.
Antifreeze Type	Corrosiveness	Flammability	Toxicity	Heat Transfer Capacity	Pumping Requirements	Relative Cost
Ethanol	Low	High (if pure)	Low	High	Low	Moderate
Methanol	Low	High (if pure)	High	High	Low	Low
Propylene Glycol	Low	Low	Low	Low	High	High
Ethylene Glycol	Low	Low	High	Low	High	High

Source: engineeringtoolbox.com

References

Original Source

Source: engineeringtoolbox.com