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Sunday 12 December 2021

Heating a Huge Water Tower 1 - a New Approach

 This old place was always going to be a devil to heat.  It is a huge volume, single glazed and with a massive iron water tank for a roof.   It was never intended to be lived in and the very idea of insulation for buildings was not on the Victorian agenda.

In a process that evolved during the prolonged planning process we settled on the following:

1.  A newly inserted steel and concrete floor would separate off a well insulated ground floor from an uninsulated first floor.

2.  There would be gas powered under-floor-heating (UFH) to both floors.

3.  In due course we would fit internal secondary double glazing to the main tower original windows.

4. We sprayed the underside of the tank with a thin coat of expanding foam to retain the shape of the girders but to prevent condensation.

5. The new-build small two-floor annex to the north side was heavily insulated to modern standards.

More than ten years on, the world has changed.  Gas is to be phased out.  Electricity is to be the thing.  Most importantly we have had ten years experience of a horribly expensive but (in the dead of winter) inadequate gas central hearing system which was found wanting.  To be fair, nobody knew how to heat a building with metre-thick outer walls, roofed by 250 tons of cast iron.  Heating costs have not been excessive, perhaps because the 27 kw (Worcester-Bosch) gas boiler could not supply enough heat.  Nor could a replacement larger 30 kw Worcester Bosch boiler.

As for underfloor heating using water pipes leading from no fewer than 14 outlets, each regulated by competing electric valves with thermostats, could not cope.   Some extremities never warmed up, the single source of boiler outflow hot water simply took the line/s of least resistance at 'balanced' water manifolds, one on each floor.

Here is the pair of manifolds (flow and return) for just the ground floor.  NINE separate loops of massively long underfloor pipes:














Expensive to fit, maintain and ineffective.  In retrospect, badly specified (by us) and extravagantly designed (by system suppliers Myson).  Every square inch of the heated ground floor had top-spec. UFH, quite unnecessarily. 

The utility-cum-boiler room was well heated by the manifolds and the gas boiler itself.  That UFH loop has NEVER been needed but there it is, expensively useless.  

Remember too, the ground floor is heavily insulated - floor, walls and ceiling.

Meanwhile on the first floor a five-loop manifold, located in a kitchen cupboard, supplies UFH to the huge main lounge / dining room (uninsulated and with the cast iron tank/ceiling) and the kitchen, a small WC and the landing.  The kitchen UFH loop was seldom on for the same reason as the utility room below - surplus heat from the manifolds and, in the case of the kitchen from cooking.

Double glazed secondary glazing was installed after a couple of years and that was very successful in terms of enhanced insulation, noise reduction (not much in Settle anyway) and elimination of window condensation.

The inadequacy of the heating in the main tower was part of our decision to build-on the two-bedroom virtually self-contained annex at the back of the tower.  It is very heavily insulated, draught proofed and heated by one 1.5 kw electric radiator.  That is occasionally supplemented by a 1.21 kw electric radiator for more even heat distribution if needed.   Its footprint on the ground is bigger than the tower itself yet a mere 2.7kw of electric radiators heat it!  

This compares with a 30kw gas boiler which fails to heat the main tower!!!!!!!  30 kw vs. 2.71 kw.

This is the modern single 1.5 kw electric radiator which heats the massive extension most of the time:










Stylish, small and never needs servicing it is located in the lounge, approximately in the middle of the  extension.  Heat-recovery-ventilation and natural movement of air distributes its heat output to other rooms.  Here is its makers plate showing its maximum output - just 1.5 kw though is is rarely on fully, depending on thermostat demand:














and the makers plate of the back-up radiator:

Total 2.71 kw.   Electricity is dearer than gas - but not ten times dearer.

The figures seem absurd but that's not the whole story.  This posting has been long so - to be continued.







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