‘A Stitch in Time – Guidance Notes in Maintaining your Place of Worship’
Guidance Note 6 – Cooling, Heating & Ventilation
Achieving reasonable comfort levels within churches can be challenging. Up until around the time that South Australia was established as a colony churches in the UK had never been heated. Only with the advent of cheap and plentiful supplies of coal in Victorian times did public buildings, including churches, have heating systems. Nowadays we all expect high levels of comfort in our buildings.
The fabric of traditional church buildings usually does not accommodate the retrospective installation of modern heating and cooling systems well, especially where the church is of historic significance. Before environmental control systems are installed heat losses and gains should be reduced to a minimum by fitting insulation and by closing up gaps to prevent unwanted air movements. Once again, the sensitive nature of historic church fabric can make insulating and draughtproofing difficult, if not impossible.
New heating and cooling systems must be designed to suit the ways in which places of worship are used – the systems required for a church used 7 days a week may not suit a place of worship that is only used on a Sunday.
There are two alternative types of heating: Central heating, that provides an even distribution of heat throughout a whole building whilst heating the fabric; and, Local heating, that dispenses only small amounts of radiant heat to targeted areas.
Because it minimises the dispersion of heat, Local heating is suitable for non-energy-efficient historic buildings because heat losses are smaller.
The left image represents the effects of Central heating. The right image shows Local heating. Image thanks to www.buidlingconservation.com
Local heating can be by heating foils, which are useful and versatile as they can be fitted into pews or under carpets or rugs. Electric infrared heaters, if positioned close to where heating is needed, can also work well. At the end of the day being warmly dressed is the best and most economic means of staying comfortable in the cold during worship.
Electric foils that can be installed within pew, within kneelers and under carpets to provide Local heating. Image thanks to www.buidlingconservation.com
Because of the large volumes characteristic of most places of worship cooling can also be difficult. Air conditioning is expensive and the large equipment required to supply evaporative cooling is difficult to hide.
A great way to achieve environmental control in large spaces is by means of underfloor heating and cooling supplied by ground or air-source heater exchangers. Drawbacks are that capital costs are high and replacing heritage floors in many historic churches may not be acceptable because of their heritage significance. The advantages are economic running costs, and the fact that floors can be heated in the cold months and cooled at hot times of the year. Also, underfloor heating can maintain a steady background warmth in the fabric of church buildings during the winter and this works particularly well where churches are used regularly during the week.
Above: An electric heated blanket designed to be used beneath carpets and rugs. These are available in a variety of sizes and shapes.
Below: Diagram showing the elements of a hydronic underfloor heating system within a ground-bearing concrete slab floor.
Good ventilation can obviously assist in keeping places cool but traditionally historic churches did not have a lot of opening windows. Electric fans can be installed but these can be noisy and visually intrusive. One solution that the author used in a church in Glasgow was to install large ceiling fans that keep the worship space cool in the summer and push the centrally-heated air down from the high roof void in the winter months.
Large ceiling fans used in a traditional church.
Cooling, heating and ventilation systems need to be designed to suit individual spaces and ways in which they are used. With the prospect of increasing energy prices these systems should also be economical in both their capital costs and running costs.
If you need assistance in reviewing suitable environmental control systems for your church building please don’t hesitate to contact Arcuate Architecture and we will be delighted to assist you.
Ian Hamilton, Director
Arcuate Architecture, Adelaide
Phone: (08) 7231 5701