Ice build up is caused when moist air enters the cold store. Sometimes there can be thin layers of ice which has the appearance of snow. When the moist air comes in to contact with cold surfaces such as floors, walls and evaporator coils, the water vapour in the air condenses to form water and then freezes to form ice.
Moisture typically enters the cold store or freezer during door opening times.
With high operating temperatures and water treatment during operation, corrosion is prevented from occurring. During shut down for repairs or on standby, the system starts to cool down and high relative humidity in the air starts to become a problem, creating corrosion.
Relative humidity must be kept at a low 30%. The sizing of units depend on variations in absolute humidity with respect to the exterior temperature difference. It works as an open system(all exterior air). Pumping air to the areas most sensitive to humidity. Air conditions must be measured in the outlets.
Corrosion is the result of the presence of sulphuric acid. This is less aggressive when its concentration increases: and the concentration increases when the environment is dehumidified. According to the graphs, the relative humidity required is 5%. We have however learned from experience that 20% is enough.
When the dry air method is used, excellent results are achieved:
It is easy to check whether there are corrosion risks, by simply evaluating the humidity in the air outlets.
It enables access to the parts conserved, while they are being protected.
Less energy is required than in the heating method, and no dangerous and expensive chemical compounds are required as for humid conservation.
All the above mentioned points of a technical and economic nature mean the dry air conservation method is preferable to all other possible methods.
Air Solutions specialises in bespoke air treatment solutions with over 30 years industry experience. Our solutions have helped customers from very diverse backgrounds ranging from archives to power generation facilities. Our vast range of experience lets us provide the best solution for your application.
It is commonly acknowledged by preservation experts, that inappropriate water vapour in the air are a real threat to the preservation of documents, artifacts and relics.
Humidity can lead to moisture damage, bacterial growth and corrosion of the object to be preserved. Once, this has occurred the object will probably never return to its former condition.
Reducing the risk of unexpected downtime is crucial for one of New Zealand’s leading dairy producers. Therefore equipment such as boilers need to be protected from corrosion when not in use. Accordingly, Air Solutions have supplied Fisair desiccant dehumidifiers to control humidity levels inside of power generating boilers.
Our client was required to carry out maintenance on specialised transformers. To complete this maintenance work, a temperature specific, very low humidity environment was required to maintain the integrity of the transformers.
Equipment such as transformers need to be kept in a low humidity environment for any repairs and maintenance. Accordingly, Air Solutions sister company in Australia have supplied desiccant dehumidifiers to control humidity levels inside of purpose built maintenance buildings.
