What Refrigerant Is Used in Absorption Chillers and Why It Matters for Your Project

Ask engineers what refrigerant runs in their electric chiller, and you'll hear R-134a, R-513A, maybe R-1234ze. Ask about an absorption chiller, and the answer surprises people: water. Plain water. The same H₂O flowing from taps.

BROAD's absorption chillers genuinely use water as the refrigerant. Understanding why this matters reveals advantages that extend far beyond specification sheets.

The Two Working Fluid Pairs

Absorption chillers require two substances working together:

For commercial buildings, hospitals, pharmaceutical plants, food processing, and most industrial cooling, BROAD's water-lithium bromide systems deliver optimal performance, safety, and reliability.

Why Water Works as a Refrigerant

Water boils at 100°C, useless for air conditioning, right ? The secret is pressure .

At atmospheric pressure, water boils at 100°C.But inside BROAD's evaporator, pressure is maintained at approximately 0.8-1.2 kPa, near vacuum. At these pressures, water boils at just 4-7°C.

When liquid water enters this low - pressure environment and boils at such low temperatures, it absorbs heat from chilled water flowing through evaporator tubes.Your facility's warm return water (12°C) gives up heat to the boiling refrigerant and exits chilled (7°C).

This phase change, liquid water becoming vapor under vacuum, produces the refrigeration effect.No exotic chemicals.No synthetic compounds.Just water under carefully controlled pressure.

The Environmental Revolution 🌍

Using water as refrigerant transforms the environmental profile:

• Zero Ozone Depletion: Water ODP = 0 (vs. R-22 ODP = 0.05)
• Zero Global Warming Potential: Water GWP = 0 (vs. R-134a GWP = 1,430; R-410A GWP = 2,088; R-32 GWP = 675)

Even newest "low-GWP" refrigerants like R - 1234ze(GWP = 6) can't match water's absolute zero impact.

Complete Non - Toxicity

If a BROAD chiller develops a leak:

• What escapes: Water vapor and lithium bromide solution
• Toxicity: None (LiBr is essentially dissolved salt)
• Flammability: None
• Emergency response: Simple cleanup, no evacuation

Understanding Lithium Bromide

While water is the refrigerant, lithium bromide plays a critical role as absorbent:

• What it is: A salt (LiBr) dissolved in water at 50-65% concentration, chemically similar to table salt.
• Why it works: Lithium bromide has extraordinarily strong hygroscopic properties, it attracts and absorbs water vapor with almost magnetic force.
• Corrosion concerns: Yes, concentrated LiBr can corrode steel. BROAD's proprietary corrosion inhibitors and resistant materials ensure 20-30 year equipment life.
• Crystallization: BROAD's multi-stage prevention systems and concentration control virtually eliminate the risk of the solution solidifying.

Why Not Ammonia - Water Systems ?

Unless your application requires sub - zero cooling, water - lithium bromide provides superior safety, simplicity, and regulatory ease:

BROAD's 30+ Years of Validation

BROAD selected water - lithium bromide in the early 1990s and never deviated.This commitment reflects performance advantages and strategic thinking:

• 25,000 + installations globally: Three decades of field experience validate the technology choice.
• Zero refrigerant - related safety incidents: No water-refrigerant chiller has caused toxicity events or environmental releases.
• Future - proof technology: As regulations tighten around high-GWP refrigerants, BROAD customers face zero compliance risk.