Heating and Hot Water

Heating and Hot Water

In most occupied buildings heating and hot water are essential components of the energy mix.

Here in the UK I think it is fair to say that we all require comfort heating for a significant proportion of the year (28-36 week heating season depending on where you are in the UK) and many sites such as Nursing Homes require space heating potentially all year round.  Hot water of course is a year round demand on any heating system.

As a result the electricity / gas / oil / lpg / biomass dedicated to heating / hot water is a major part of many buildings energy burden.

There are so many different mechanisms with which you can heat your property that I have split this section into what I have found to be most frequently visited areas for my client base.

I hope that you find this approach useful – if nothing else it helps me get my head around the various options!

  • Boilers – so this is where I talk about the different types of boiler plant I have identified, basic details on the way they work and my thoughts on their efficiency / effectiveness 
  • Heat Pumps – an upcoming area in the world of HVAC – heat pumps have been around for ages but still seem shrouded in myth – no longer – Stewart debunks myths (I hope)
  • Electric heating – wall mounted – many buildings have no choice but to work with electric heating – here is where I talk about some systems I have found and like / dislike
  • Electric Heating – ceiling mounted radiant panels – slightly different approach here – industrial / commercial “black heat” – good for churches by the way
  • Industrial heating – no link here yet  work in progress
  • Radiators – a wee bit about how to distribute heat from your boiler system effectively


Few energy-saving measures give better payback than improved automatic control, but equally heating and hot water control systems that go wrong can accrue high hidden avoidable costs.

  • Frost protection – easily overlooked but potentially very wasteful since by default it is attributable for energy use when there’s nobody around to realise it – it is also difficult to verify that it is actually operating effectively.
  • Time control – overridden time controls are most likely to incur needless consumption “out of hours”.   Temporary extensions that become permanent.  Incorrect and unauthorised changes to settings.  Malfunctioning optimizers all contribute to energy waste.
  • Temperature control – space temperature set too high, occupants opening windows to compensate for over-heating but not turning off the heating.  Air-Con set-points too low and heating ON to compensate – I have actually surveyed an office where heating, cooling and windows open were all happening at the same time in the same space – utter madness.
  • Humidity control – too tight limits incur costs, valves and dampers, actuators and linkages failing within chill-and-reheat sections – difficult to spot except during servicing.
  • Zone control – each individual zone can have its own time and temperature control faults as described above.  Zone control hardware itself can develop faults that cause waste, for example through passing valves or reverse flows allowing idle zones to consume energy when others are active.
  • Sequencing control can fail allowing superfluous heating boilers to be left in circuit, dumping heat up the flue, a problem exacerbated by the purge losses as burners start and stop far more frequently than they need to – no superficial sign for occupiers so easily unnoticed.

Controls are great and clearly necessary but they have their limitations.


If anyone can explain this to me I’d be grateful – radiator installation at Castle Howard in Yorkshire.

Strange radiator set-up at Castle Howard - heating and hot water