As part of this year’s Big Draw event at Culzean, the team looked at the engineering heritage and history of the site. One of the buildings that the participants were asked to go and investigate was the Camellia House.
The Camellia house was built in 1818 possibly by James Donaldson (pupil of Robert Adam, Culzean Castle’s architect and designer). Originally planned as an orangery with an underfloor heating system, it failed to produce fruit and so simply acted as a conservatory. Camellia flowers were very successful though and gave the house its later name. The building was abandoned but was repaired in 1964 and restored in 1995 with new windows and the heating equipment was removed at this time from the basement.
This original system was a hypocaust system, one of the most ancient forms of heating systems introduced by the Romans more than 2000 years ago.
The NTS excavated Camellia House in 1994 and 1996. They discovered the boiling system was powered by heat from 2 external fires to create warm air which was then distributed underneath the stone-slabbed floor in the house. At the back of the house you can see the steps leading towards a brick arch which would have provided access to the two boiler chimneys.
The only controls were on and off as you cannot control the heat coming off an open flame. The lowest temperature was controlled by the outdoor temperature and the maximum temperature was around 37ºC. Humidity can also be added by heating pools of water. Hypocaust systems are no longer used because toxic fumes including carbon monoxide created by the fire in the furnace often crept into the main building. Also if the fire went out of control it could easily destroy or damage the building and anyone inside.
How did the steam underfloor heating system work?
In the late 1800s or early 1900s a steam heating system using cast iron pipes was installed to replace the old system. Steam heating systems were invented by William Cook in 1745 in England. The system that was removed here contained a furnace to create the steam in the boiler house and cast iron pipes which would have been used to distribute hot steam under the flooring. In the 1994 excavation diagram shows the area a boiler house at the back where the fire arch is and a water collection area can also be seen because to make steam we need water.
Blog post written by Helen Cromarty, Seasonal Countryside Ranger.