Low charge ammonia (NH3) is climbing the ladder in the industrial sector. Applications getting bigger, charges getting smaller.

Having less toxic refrigerant in a system is a great advantage for safety and susceptibility to regulatory standards. The “more is better” philosophy concerning the charge is getting rejected. Only the essential charge is filled, and the heat is transferred to a secondary fluid or the air is maximised.

The size of the ammonia charge in any facility has been largely examined and discussed by regulatory authorities, communities, and insurance providers.

But what exactly is low charge? Two major viewpoints are being discussed. Some people say that the definition should be based on the specific charge used per system and the cooling power provided. Others respond that the total amount of the used refrigerant is sufficient. There tend to be a favour for the specific charge rather than to the cooling capacity.

There might be need of a definition of maximum allowable charge so regulatory burdens can be avoided. This also might help boost the technology forward.

Examples of technological advancements that can decrease the charge in the system are:

• Advanced auxiliary components optimised for NH3.
• Specialized controls for exact liquid metering.
• Heat-transfer technology with higher coefficients.
• Specialized manufacturing components.

One thing is for sure, the discussion is not yet over. In the meantime, low charge ammonia systems are climbing the ladder in industrial applications. So, efficiency and green technology is uprising.