Notes for a presentation by Andrew More about the reuse of a historic heating system within a church, given at a conference on historic parish church interiors.

1. December 2015
Parish Church Interiors in Changing Times - Revitalizing and Rebuilding
Slides v. Script: An historic ‘Perkins’ heating system re-used and expanded to meet modern heating requirements Page 1 of 4
Slide - text wording unless otherwise stated Script
Revitalising and Rebuilding:
An historic ‘Perkins’ heating system re-used and
expanded to meet modern heating requirements
Good morning etc.
Andrew More
Senior Building Services Engineer
Building Services and Emergency Planning Team
Conservation Department - Planning Group
Historic England
A brief quiz to prompt discussion to get us going
Consider the following three current vehicles…
A brief quiz to prompt discussion to get us going.
Picture: Toyota Prius A rather sad looking Toyota Prius parked near my
home.
Picture: Land Rover Defender The last model of the Land Rover Defender.
Picture: Jeep Wrangler The four-door version of the Jeep Wrangler
Toyota Prius: petrol/electric hybrid; steel body; large
battery pack and lots of complicated electronics.
Land Rover Defender: diesel engine; steel chassis;
mostly aluminium body; some electronics.
Jeep Wrangler: diesel engine, steel chassis and body;
more electronics than the Land Rover Defender.
Toyota Prius: petrol/electric hybrid; steel body; large
battery pack and lots of complicated electronics.
Land Rover Defender: diesel engine; steel chassis;
mostly aluminium body; some electronics.
Jeep Wrangler: diesel engine, steel chassis and body;
more electronics than the Land Rover Defender.
Question… From extracting the raw materials, all stages of
manufacture, through use to eventual dismantling
and recycling, which of the three vehicles is the most
environmentally friendly?
As they say in exams: discuss! [Discussion]
[TP - short life, even shorter battery life - very
expensive to replace, difficult to recycle]
[LRD - very long, if not indefinite life; aluminium
expensive to make though]
[JW - long life, cheap to make and recycle]
[LRD and JW probably about equal?]
The concepts of ‘embedded energy’ and’ the
adaptation and restoration of (historic) equipment’
will be revisited later
The concepts of ‘embedded energy’ and’ the
adaptation and restoration of (historic) equipment’
will be revisited later
Picture: tombstone
Text: Death by PowerPoint
To avoid ‘Death by PowerPoint’ I’ve put a lot of useful
information in the handout to be read at your leisure.
Historic England
Planning Group
A brief mention about Historic England and how it
gets involved with listed buildings.
Development Management:
Inspectors of Historic Buildings and Areas
Inspectors of Ancient Monuments
Heritage at Risk:
Architects and Surveyors
Nine regional offices
We advise, by request from them, various types of
inspectors, architects and surveyors who work out of
nine regional offices. More details in the handout.

2. December 2015
Parish Church Interiors in Changing Times - Revitalizing and Rebuilding
Slides v. Script: An historic ‘Perkins’ heating system re-used and expanded to meet modern heating requirements Page 2 of 4
Picture: church interior
Text: The Parish Church of St. Michael and All Angels
Cornwood, Devon
And so to the Parish Church of St. Michael and All
Angels or Cornwood Church for short. A ‘Grade I’
Anglican Parish Church. The village of Cornwood is
located in the Dartmoor National Park, about ten
miles to the east of Plymouth and a few miles north of
Ivybridge, the nearest railway station. Listing
information for the church is in the handout. The
church had a heating system that wasn’t terribly
effective and it wanted to do something to improve
matters. My colleague, Geraldine O’Farrell and I, a
colleague, Frank Ferris from the CIBSE Heritage Group
and Francis Kelly, the Inspector of Historic Buildings
and Areas, met with the Church Wardens, the Church
Architect and the DAC Heating Advisor in July 2012 to
see what could be done.
Picture: floor grille covered over The church was originally heated by some
undocumented system using large grilled voids in the
floor - rumour has it these used some form of solid
fuel burning in a grate or basket lowered into the void,
but how exactly these operated is unknown and if
anyone finds out or has any ideas, we’d like to hear
more about these.
Picture: big pipe coil in silver The church’s second heating system was a Perkins
heating system and most of this, albeit modified, was
still in use - this comprised a number of pipe coils like
this
Picture: pipe loop and some pipe loops like this all joined by pipework in
two circuits.
Chartered Institution of Building Services Engineers
CIBSE
Heritage Group
Web site: www.hevac-heritage.org
Perkins systems were installed from the 1830s to the
1890s and were some of the earliest types used in
buildings. Surviving systems by the Perkins family are
now very rare and need to be preserved. Those still
working, now in modified form, are especially unusual
and further changes to them so that they can
continue to be used, and where feasible, their
capability enhanced, need to be carefully considered.
Much more about Perkins and the Perkins systems
can be found on the CIBSE Heritage Group’s website.
Picture: pipework diameter comparisons - to be
prepared in CAD (possibly scanned in as a JPG)
The original system was designed to be operated at
high temperature and high pressure and pressurized
by a sealed vessel and was fed a solid fuel stove, now
long gone. It was now downrated to usual
LPHW/LTHW standards and fed by a conventional oil-
fired boiler, pressurization unit and pump. Whilst the
boiler was sized correctly to match the heating load
and the pump had the right flow rate (or thereabouts),
there wasn’t enough pipework to give sufficient heat
output and the pump wasn’t sized to account for the
very high resistance caused by the very thick wall of
the piping used.

3. December 2015
Parish Church Interiors in Changing Times - Revitalizing and Rebuilding
Slides v. Script: An historic ‘Perkins’ heating system re-used and expanded to meet modern heating requirements Page 3 of 4
Picture: big pipe coil in brown The silver paint didn’t help matters and would have
cut the output by 50% - all to do with the emissivity of
the outer surface finish of the pipework. Overpainting
with ordinary gloss oil paint or a gloss varnish will
restore the output. This was an easy fix and all the
pipe coils, pipe loops and pipework was re-painted -
some will be re-painted to better match the
background surface colour. Guidance on standard
paint colour systems we suggest so that future
redecoration is made easier is given in the handout.
Picture: painter
Text: A query - perhaps you can help solve it!
A brief aside - a query has arisen: what colour were
these and other older heating systems painted? Were
they just left in bare metal, perhaps polished with the
same ‘black lead’ graphite treatment applied to coal
fired ranges and the like, or were they actually painted
in some type of black paint? Did painting come later -
if so, when? E-mail your thoughts or any findings
made in the course of other research e.g. into parish
records to us please.
Pictures: digital clock, clock and thermometer Back to Cornwood Church… Another easy adjustment
was to run the heating system constantly at a lower
temperature (12°C was chosen by the Parish) and then
boost it for services and other occasions when the
church was being used. This sounds counter-intuitive,
but once the Parish had an indifferent thermostat
replaced, this method of operation worked well with
no difference in oil consumption, even whilst waiting
for the thermostat to be replaced (it couldn’t quite get
down to 12°C), the revised method of operation only
used a little more oil. Modern digital controls,
especially those wireless systems that can be driven
by smartphones and tablets, makes setting up and
experimenting with systems, to fine tune the heating is
highly recommended.
Picture: worried man
£15,000.00 for five special-size flat steel radiators!!
We suggested a means of inserting some extra flat
steel panel wall-mounted radiators to give a neutral
appearance against the mostly plain walls into the
Perkins system. This would have retained a lot of the
Perkins pipework and all of the pipe coils and pipe
loops, but would have required special pipe adaptors
to be made up for welding into the Perkins pipework.
The Parish had a system designed, but the cost of the
five radiators required was a staggering £15,000.00.
Picture: reclaimed radiator The Parish did some lateral thinking and salvaged
from a Victorian Gothic Horror of a church in
Plymouth that was being demolished because it was a
failed building of no architectural merit or future
utility a number of ‘Princess’ cast iron column-type
floor-mounted radiators made by Beeston of
Nottingham, probably dating from between 1900 to
just before WW2. These seem to have been installed

4. December 2015
Parish Church Interiors in Changing Times - Revitalizing and Rebuilding
Slides v. Script: An historic ‘Perkins’ heating system re-used and expanded to meet modern heating requirements Page 4 of 4
by the local contractor ’Haden’ judging by the air vent.
A member of the local community kindly paid for the
transport of the radiators on the back of a flatbed
truck with a crane on board and more members of the
community manhandled the radiators approximately
into position and the parish asked again for our help
and guidance.
Picture: another reclaimed radiator Most of us gathered again in April 2014 and we
thought the easiest way forward would be to run a
new set of pipes around the church to just serve the
reclaimed radiators in a form and location that
mimicked the Perkins distribution pipework and this
design was costed and found to be affordable.
Picture: corner pipe detail This was installed, along with some new additional
wall-hung cast iron column-type radiators that match
the Beeston Princess radiators reasonably well. The
system works well and the church is nice and warm as
Francis Kelly and I found a few weeks ago when we re-
visited site to help the DAC sort out some Faculty
permission problems. These will be addressed next
summer when the heating can be turned off. An
example is some of the bends of the new pipework
(above) which need to be swept welded steel (or
formed copper) bends to match the Perkins pipework
(below). Some pipework still needs boxing in, a short
piece extending slightly to make the boxing in more
effective and some air vents added at high points. All
straight forward for the parish and their contractor to
do.
Pictures: more re-usable radiators
(Ladbroke Grove, London)
(Wrest Park)
(Litherland, Liverpool)
It can thus be seen, with careful thought and attention
to detail, that an original heating system dating from
the start of central heating as we now it can be
modified to suit the needs of today and future years
thus making sure that all that embedded energy
expended in the past in its manufacture doesn’t go to
waste. Such systems, with good water treatment and
care, can be re-boilered, re-pumped and re-controlled
almost indefinitely into the future. Here are a selection
of other elderly, but otherwise serviceable radiators
and systems that we have found, either still in use or
able to be re-used if they pass simple leak and
pressure tests.
Thanks for listening! Thanks for listening!
Photo credits:
Andrew More - Historic England
Geraldine O’Farrell - Historic England
Keith Dodds - Exeter DAC Heating Advisor
Cornwood Church - Churchwardens
Jeep USA
Studio Briggs Archive courtesy of Roger Kennett Design
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