Central Heating Boilers
Boilers as we mostly know them come in a massive variety of colours (seriously – from shiny white through blue red orange and of course my favourite – deep rust – see below), shapes and sizes but to be honest most of you reading this will only need to know that there are two main types – Atmospheric and Forced Draft. I’ll deal with Steam systems somewhere else on this website.
They are fired on natural gas, LPG, heating oil (28 sec kerosene) and biomass – and I shall attempt to cover all of this below.
The vast majority of boilers that I come across serving commercial buildings are atmospheric low pressure hot water systems delivering heat to the property via radiators, underfloor circuits or as warm air from fan coils or heat exchangers in air handling systems but as you can see from the selection above they really are not all the same and some are very complex – although most are not.
An Atmospheric boiler is simply one in which combustion air and flue gases are drawn through the boiler without a fan whereas a Forced Draft boiler employs a fan to raise the pressure of the gas and combustion air prior to ignition. Obviously this is a simplistic over-view and I am not going into the differences between low, medium and high pressure systems at this time – suffice to say that should you wish to discuss these more intricate matters you can always call or email me.
So, a boiler is where water is heated by a flame created by burning air and fuel and that water is then used to heat treated spaces or goes to storage for Domestic Hot Water (DHW). Boilers tend to appear complex – they are hot and often noisy – they tend to be looked after by engineers who dabble like Professor Snape in the dark arts – but in reality these are pretty simple bits of kit that should not be scary and should not be the subject of “blinding with science”.
The first major problem I almost always encounter is a serious lack of servicing data – for example the last flue gas analysis ticket taped to the side of the boiler casing so that you can immediately see operational efficiency – why is it never (ok sorry – rarely) to be found?
Second frequently observed problem – boiler casings – these things are there for a darned good reason – they are insulated and they prevent large amounts of radiant losses to the boiler room – so please please please put the blasted casings back on when you have finished looking at the boiler!!!!!! Above are three boilers above lacking casings – I didn’t take them off – that is how I found them.
Then we get onto the thorny issue of inefficiency. INEFFICIENCY I hear you shout – not my boiler – I have a brand new all singing all dancing, fully condensing with bells attached, optimised, compensated, heat recovered, balanced flued, triple insulated, ideally located and ventilated, oft-serviced, index-linked top of the range model – hmmmmm – maybe.
OK I grant you there are some very good systems out there, well maintained and set-up to cater for actual demand on site but trust me – these are the minority.
Whether it down to lack of insulation, shoddy or non-existent servicing, poorly maintained controls, badly set time-clocks (even if it just forgetting to spring forward or fall back), over-sizing, under-sizing, failure to address return flow temperatures so that condensing does actually occur, no lagging on pipes, valves, flanges or behind radiators – crikey the list just goes on and on.
I have access to a variety of solutions to all of these issues – from simple Valve-Wrap and Climaflex pipe-wrap to Load Compensating controls that work hand in hand with your Building Management System. From behind the radiator insulation panels to Radiator Fans that boost the heat input to the treated spaces.
There are any number of myths and legends surrounding boiler control – and retrofit boiler controls – here are just a few of them – laid out and busted.
Time-clocks are infallible! The number of times I go to a property and find that the occupiers rely on time-clock settings that may have been programmed before the first moon landing (ask your Dad if that means nothing). Time-clocks often default to factory settings if there is a power cut. Many timers show Mon-Fri and Sat-Sun on first run through but on second run allow you to programme each day independently – why fire up the boiler on a Sunday if you are closed? If you close the shop at 6.00pm try turning off the heating at 4.30 and the hot water at 3.30 – just a suggestion and each building is different but hey – think about it.
The BMS – essentially a very sophisticated time-clock – ok ok it does much more than that but aside from allowing you monitor and switch things on and off the BMS doesn’t generally look at individual boiler settings and so once a BMS has turned a boiler ON it has very little to do with it until it turns it off again – so it is the bit in between that interests me.
Dry Cycling – this is an over used term that describes burners firing when there is no true heat load – and it is caused by standing losses from the system (for example unlagged pipes, poorly insulated boiler casings, poorly set-up internal thermostats). It can be readily overcome to achieve substantial savings bu retrofitting load compensating controls – self-learning energy saving systems that monitor individual boiler temperature profiles, reacting appropriately to return flow temperatures to operate burners only as and when needed.
Tell you what
I will never try and sell you magnetic devices that miraculously enhance burner efficiency (because they don’t!!!) or additives that increase the thermal efficiency of your fuel (because they don’t either) or any sort of “snake oil” which holds great promise but no reality (thanks to my friend and colleague VilnisVesma for the image below).
So, if you have a boiler and you would like to save some money in the operation of your heating system, get in touch!
What exactly is an Electric Boiler? Well as my lovely customer Roger Still (Ythanbank Aberdeenshire) will tell you – they are hellish beats that cost the earth to run and don;t heat the house properly.
Fortunately for Roger help was at hand and I have managed to find him and his wife Pat an Air Source Heat Pump system (air to air ducted throughout the house) for comfort heating and I have replaced the horrid electric boiler with a Rointe digital how water cylinder.
Like all things however, horses for courses. There are times when an electric boiler is your only option and so if you in that position a wall mounted ultra-slim vertical assembly requiring very simple pipework connections and complete with state of the art electronic control system is probably your best bet. Essentially they work by passing cold mains water over replaceable heating elements housed in an insulated steel heat exchanger.
I am aware of them in sizes from 2kW – 12kW and because they are 99.8% efficient they offer a great alternative when mains gas is not available and it is a hot water system you require.
There are several systems on the UK market and if you care to email me with your enquiry I can send you Cdetails of those that are suitable for your property.