| As you may well know the newer condensing | | | | Heating - If you are having new radiators installed, |
| combi boilers are upto 93% efficient. They will | | | | each and every room needs to be measured and |
| ONLY be this efficient if they are run at maximim | | | | the heat loss needs to be measured individually. |
| capacity all of the time. The new boiler will | | | | There are free heat loss calculators available online |
| specify what KW output it has and the direct | | | | which allow you to enter figures simply and easily |
| hotwater output DHW. This will be in litres per | | | | and it will come out with a minimum figure in |
| minute. | | | | BTU's the radiator must be for that particular |
| Choosing a boiler can be a very difficult propostion | | | | room. It takes into account such things as cavity |
| as you will need one which is large enough to | | | | wall or loft insulation, double glazing, whether its a |
| cope with your hot water demands and small | | | | bedroom, lounge or common area like a kitchen |
| enough to still be efficicient. An oversized boiler will | | | | or hallway and how many outside walls that room |
| not bring the energy saving that you might be | | | | has. Obviously each room will lose different |
| hoping. | | | | amounts of heat during the day because the |
| This guide will help you to choose a suitable boiler | | | | room make up is different so this means that |
| for your hot water and heating demands by | | | | radiators will need to be different sizes. In the |
| calculating the heat that is lost from your | | | | past it was acceptable by some to guess radiator |
| property and estimating your daily hot water | | | | sizes but now a more professional approach has |
| requirements. | | | | arrived. |
| Hot water - your needs will depend on how many | | | | There are lots of free online BTU calculators you |
| showers you have in the property. ie do you | | | | can use but there is a quick and easy way. |
| have a family bathroom and an ensuite which will | | | | Measure the room in cubic feet and apply the |
| likely be running at the same time? Do you have | | | | following factors |
| a large family who wake up the same time every | | | | Lounges and dining rooms - multiply cubic feet by |
| morning and therefore place a great demand on | | | | 5 |
| hot water at certain times in the morning? | | | | Bedrooms - multiply cubic feet by 4 |
| A £500 Glow-Worm Betacom 24KW will run | | | | Common areas and kitchens - multiply cubic feet |
| radiators upto a maximum of 80,000 BTU's of | | | | by 3 |
| output which is generally enough for a small to | | | | For rooms facing north - add 15% |
| medium size property. However, the DHW is only | | | | For French windows - add 20% |
| 10 litres per minute. This will provide an adequate, | | | | For double glazing - deduct 10% |
| but not great, shower and will take longer to fill a | | | | This will give you the output of any radiator in |
| hot bath than most boilers. | | | | BTU's (British Thermal Units) Adding the total for |
| A £1100 Vaillant EcoTEC Plus 837 which is just | | | | all the rooms in your property will give you the |
| 28KW will run upto 14 radiators if installed | | | | approximate demand in BTU's for the whole |
| correctly, however this combi boiler provides 15.2 | | | | house. You should add another 20% to the total |
| litres per minute. I am sure you will apreciate that | | | | for a hot water circulating tank and 10% for |
| it will be a much more powerful shower and will | | | | general losses. This will then give you your boiler |
| be possibly to run 2 showers at once (just about). | | | | size and you will be in a better position to make a |
| The difference is £600 but you will be getting a | | | | judgement. |
| better quality boiler with a longer warranty for | | | | What do I do next? |
| parts and labour and you will have the added | | | | When you know your hot water and heating |
| benefit of a more powerful heating system, In | | | | needs you need to choose the best boiler for |
| the long run the £600 will be paid back and | | | | your budget. |
| more. You also need to consider the extra | | | | Things to consider will be: |
| warranty the boiler gives you. For every extra | | | | Reliability of boiler, manufacturer warranty, ease |
| year of warranty you wont have to pay for any | | | | of installation, service and repair, new boiler |
| HomeCare agreement with British Gas you might | | | | cost and availability of parts. |
| have which saves even more pounds. | | | | |