Heating and energy use
Churches need to run their heating systems as efficiently as possible.
One of the first steps for churches and people to save energy and carbon emissions is to review our church’s heating system and its settings.
An efficient heating system also saves costs.
Heating is a major user of energy in any building. It is important not to waste heat, and to run it at the lowest temperature consistent with comfort and health.
Heating can account for about 75-80% of your energy consumption, 50-55% of your energy bills, and 55-60% of your church’s carbon footprint.
Churches tend to be stereotyped as ‘cold and draughty’. Indeed some are that. It is not usually because they are unheated, but rather because so much heat needs to be emitted in order to warm up the interiors of such large buildings.
Ways of heating churches vary, from traditional ‘wet’ radiator and pipework systems through to electrical sources of heat.
Electricity has hitherto been disfavoured as a principal heating method – it can be very wasteful and expensive. However we are going to need to switch to electricity, as it becomes increasingly low carbon.
Thermostats and settings
Comfort expectations have risen hugely. Heating should meet but not exceed minimum comfort standards – members of the congregation should not expect to be wearing shorts and T-shirts in church in February!
The wellbeing of the elderly and infirm and young children should of course be taken into consideration. As well as the church’s spending on energy. Bear in mind that some in your congregation may be suffering fuel poverty.
Just a one degree reduction may be expected to save approximately 8-10% of heat energy.
Boiler-driven systems will have a thermostat on the boiler itself, and another wall-mounted at some central point.
The wall/room thermostat controls the temperature in the space – the boiler power and thermostat control how quickly and efficiently it reaches it. An optimal location for the room thermostat is critical to efficient energy management.
Individual heaters or radiators may also have thermostats – if not, it is well worth installing thermostatic radiator valves (TRVs), and making good use of them, at least where a space is partitioned into smaller rooms.
Programmable TRVs are now available – you don’t have to keep fiddling with them!
The exact amount to lower the temperature depends on the current setting; whereas the optimum setting depends on the efficiency of the heating system, and the thermal characteristics of a building.
Anything in the range 16-19 deg C may be appropriate in different church buildings, with an average somewhere in the middle of that range.
It is very energy and cost effective to install the latest intelligent time and temperature controllers to hot water boilers, immersion heaters and any circulating pumps – so that they are set to provide heated water only when needed.
Typically, programmable controls will now use internal and external temperature sensors, selecting optimum settings in relation to both.
In exceptionally cold weather, it may be best to turn up the gas heating, especially if the heating is zoned, enabling concentration of heat where it’s most needed.
A higher setting may be needed to achieve minimum comfort, due to temperature drops towards cold spots.
Alternatively, meetings can be moved from the main church space to smaller rooms. These may heated independently often with electrical heaters. This avoids wasting heat by sending it wound the whole circuit for the sake of one smaller space.
However, electric portable heaters should be avoided if possible. Gas portable heaters are dangerous, and a ‘no no’! Any portable heaters are a hazard and may compromise your church’s insurance cover (ask your insurer). (The same may also apply to free-standing lights or fans.)
Turning down the knob applies to heating, but not in the same way to hot water.
60 deg C is usually the right maximum temperature for hot water – for at least one hour per day – too hot for legionella (any higher temperature increases the risk of scalding).
For vessels with a programmable thermostat, it is advisable to programme the maximum temperature to end just before any time when showers are taken – to stop harmful bacteria getting onto shower heads – and immediately after the end of any period of shut-down. A lower temperature, say 40 deg C, can be programmed at other times.
- Make sure there are no unnecessary obstructions in front of radiators, heaters and air ducts;
- Bleed your radiators and have them cleaned on a regular basis, to ensure water circulates properly. Clean off the fluff and dust from the grill and filters of convector radiators and heaters;
- Check for draughts and damage to windows, window frames and doors. Repair any damage and install or maintain draught seals where there are air gaps. Contact the Parish Property Support Team regarding any repairs to window glazing;
- Make sure that your heaters and boilers are serviced regularly, at least once a year, and ask for a report on combustion efficiency;
- Insulate hot water tanks and piping. You do not want expensive heat leaking out.
In addition to considering temperature settings, it is important to improve insulation where feasible.
Church roofs are often cavernous spaces, through which up to a third of the building’s heat can be lost. If your church has an empty loft space, filling it with insulation could prevent the lion’s share of this heat escaping.
However, historic buildings require natural ventilation. Care must be taken when considering any insulation in churches to ensure that no harm is done to the building fabric. Please consult your Quinquennial Inspector (QI) about any such proposal. You are also likely to need a faculty.
You can also prevent heat loss by investigating the possibility of cavity wall insulation, if there is a gap between your inner and outer walls. This may sometimes be feasible for a newer church hall, for example.
However this is rarely possible in pre-1914 church buildings as these are generally of solid construction and do not have cavity walls. Again, consult your QI and the DAC (Parish Parish Support) when considering any works.
Replacement heating systems
If your boiler or heating system is failed, or is requiring frequent repairs, or in some cases just if it has suffered a drop in efficiency, then you should upgrade to a fuel efficient system.
Lighting and energy use
Switching to green energy
Climate Action Projects.
Head of Environment and Sustainability
Parish Property Support Team
Getting your faculty.
Environment and Sustainability, front page.