Hanwell is a manufacturer of wireless environmental monitoring equipment, its instruments playing a major part in protecting famous heritage and historic landmarks, including the only three surviving in-situ ceiling canvas paintings by Flemish artist, Sir Peter Paul Rubens.
One of the original challenges facing the team from Historic Royal Palaces was being able to gain accurate temperature and humidity data near to the surfaces of the canvases.
Hanwell originally installed traditional temperature and humidity sensors, which provided the much-needed data required by the conservators to assist in establishing the condition of the canvases. An inherent problem with relative humidity sensors is the need for regular calibration in order to continually provide accurate and reliable data. Due to placement of most sensors, extensive scaffolding is required which is extremely costly and disruptive, therefore regular sensor calibration to ensure completely reliable results was not possible.
The next challenge was how the temperature and relative humidity sensor (T/RH) of the ceiling could be reliably monitored over a long period.
Due to Hanwell’s ability to develop bespoke solutions an innovative solution was developed using existing high stability temperature sensors. The stability of these sensors – the fact that they rarely 'drift' - has been proven in field service over 20 years.
Using these sensors, and one single T/RH sensor, Hanwell wrote a custom algorithm to calculate the Relative Humidity at the ceiling based on the temperature measured there, eliminating the need for inaccessible sensors to be calibrated. Two groups of sensors were installed, one linked to the space above and one linked to the space below the ceiling. Each group consists of several temperature-only sensors and one T/RH sensor. The RH levels at the ceiling are calculated and converted to signals from virtual T/RH sensors which are then displayed in the Hanwell software for monitoring and reporting purposes. The only sensor requiring calibration in each group is the single T/RH sensor which is easily accessible.
The original software from Hanwell was generally a standalone system making connection to other buildings very difficult. As part of the same project, the decision to upgrade Hanwell’s software from RadioLog to a centralised web-enabled system was an easy one for HRP as it immediately reduced the amount of time and resources needed to gather the environmental data, by providing the ability to add all other properties under Historic Royal Palaces control into a single software platform. Centralising the software reduced maintenance and costs as the software now only exists in one place. The staff can now log on via a web-browser from anywhere to view their data.
This has resulted in aiding the conservation team to preserve this unique artwork for years to come, avoiding costly regular scaffolding requirements
Following the success of the system upgrade, the conservation team in Whitehall is now able to easily monitor and manage the conditions around Rubens’ Ceiling because they can interpret, share and react to critical environmental changes more swiftly. The system can instantly provide alerts via email, SMS and mobile app.
Hanwell business development executive Jason Todd explained: “The series of three canvas paintings has lived through almost 400 years of alterations, restorations and preservation projects, including its removal and replacement during the Second World War. Having the opportunity to get right up close to the art work, five stories high, was incredible. It was fantastic to be a part of this restoration project, whilst supplying a cost effective solution to the organisation to aid in a way no other competitor could.”
Stable environmental conditions are vital for art collections to help prevent damage to paintings, drawings, prints, mosaics, sculptures and buildings. The accuracy and flexibility of environmental management provided by Hanwell potentially protects heritage sites from damage to irreplaceable historical and cultural items by instantly warning of compromised conditions.