Problems with pressurised ammonia

Hit a brick wall with the building of the absorption refrigeration (Einstein’s fridge and solar ice maker) prototypes.

Having acquired most of the materials and completed construction of the condenser, heat exchanger and solar concentrator I have realised we are unable to fill the system with pressurised ammonia unless we comply with the never ending list of regulations for pressure vessels and even more regulations for using ammonia.

Critically, all welding must be done by a coded welder and the completed system must be inspected and underwritten by an insurance company. This means it will be far more expensive and time consuming than originally expected.

Furthermore I have realised that using pressurised ammonia means all the pipes and fittings have to be of very high specifications to comply with the safety regulations which also adds to the cost. For example for the solar ice maker the two valves alone costed £69 , the two end caps for the generator costed £75 as they had to be made of steel to resist ammonia attack and withstand the pressure of 200psi (actually rated to 1000psi for steam).

Even if we were to complete the construction of this prototype, how sustainable would this solution be for implementation in rural locations in developing countries? Where would we find a coded welder and all the high spec parts locally? Even so, would it be financially viable to construct and maintain in the long term?

On the other hand the proposed adsorption system would operate on air/ water vapour at atmospheric pressure. Therefore it could be made with much cheaper, easier and safer to construct and maintain locally.

Therefore I am considering discontinuing the construction of absorption refrigeration system prototypes to concentrate future work on developing the proposed adsorption system.