St Ninians Old Parish Church Reduces Energy Consumption of Church Hall by 65%

Mike Adam

Mike Adam of St Ninians Old Parish Church has emailed us the latest energy saving figures from their refurbished church halls.

The good news is that over the 6 month period October 2010 to end of March 2011, our electricity usage was down by 65% compared to the previous winter. So they work. It did take the Playgroups some time to get used to them, but they are now converted to them and happy.

Here is the full information on the project and a link to further information on energy reduction in churches:

For St Ninians Parish Halls, we had identified at a fairly early stage that Air Source Heat pumps would be a desirable option to heat the halls. We too had advice from a CES appointed heating engineer/advisor, who had a preference for ground source heat pumps - but that would have been a much more expensive capital project, and I carried out a cost benefit analysis to show it would not be worthwhile. Sometimes advisers focus on technologies in which they have significant experience, and Air source Heat pump technology is new(ish) developing and improving fast - so quite demanding for consultants to keep up with. My own view is that contractors may be more up to date - but with the disadvantage of not being unbiased.
We looked at both air-to-air and air-to-water heat pump installations. Whilst the latter might be slightly more efficient, it is better suited to properties needing heating 24/7. A-WSHPs would also require a 'wet system' of pipework and radiators to be installed - intrusive, more expensive, and potential water leakage problems for the future, as well as having unsightly radiators on the walls. The attraction to us of A-ASHPs is that they can be switched on and provide heat within a few minutes. This fast response time suits a building like ours which does not have to be heated in all areas, all the time. It has frost protection installed, to maintain the building fabric significantly above freezing. This past winter was our first, the system having been commissioned in October 2010, and we did experience some problems with keeping temperatures high enough for pre-school children's groups who use the main hall each weekday morning. However the problem turned out to be that the air filters in the internal units had blocked up - once they were cleaned (a relatively easy operation) the problem was resolved. The problems we had were due to focussing too much on how early we should set the timers for the system to come on, and failing to recognise this technical issue. So I don't think that the AASHPs will be a problem for temperatures down to around -15C, as we experienced last year, though clearly their efficiency drops off with outside temperature.

The good news is that over the 6 month period October 2010 to end of March 2011, our electricity usage was down by 65% compared to the previous winter. So they work. It did take the Playgroups some time to get used to them, but they are now converted to them and happy.
We didn't retain the old radiant heaters as back-up, because they were old & unsightly and it would have cost us to get them rewired. Moreover it would have been too easy for users to select them rather than wait the 5-10 minutes for the AASHPs to get going.

I would say that it is so important to get the right contractor to do the installation. Get as many to come out and see the halls as early as practical, to get and assess their ideas. I know that our selected contractor, [name of contractor] , gave me the confidence they knew exactly what to do and how. They offered the best equipment - at the best price - and the most practical control features, which other tenderers could not match.

It is worth noting that the AASHP installation cost around £25K (we didn't have to pay VAT as it is a listed building, but VAT would only be at 5%), compared to £170K on insulation. The latter was much more expensive due to the standard of renovation required for a listed building. Without a major grant and planning constraints, a significantly less expensive insulation approach would have been adopted, but still focussing on proving 400mm glass wool insulation in ceilings, secondary glazing, and looking into practical cheaper options for insulating the walls. If we had had adequate space and access, underfloor insulation would have been considered. We were also able to get low energy lighting units with our grant from the Climate Challenge Fund, but under other circumstances they may have been lower priority. We also had to cope with a sizeable amount of wet rot, which was thankfully exposed by the improvement work.
Also see the description/photos in the following website:
http://church-cost-reduction.posterous.com/