It's never been more cost effective to invest in saving energy than it is now, and will be this coming winter. Previously, it's been marginal gains and often driven by environmental awareness rather than the actual cost savings as the return can be a long way off.
The main use of energy in the home is heating 61% and hot water 23%. As a heating engineer these are my areas of expertise, the other 16% is not covered here, but by no means should not be forgotten.
Get Some Expert Advice
I believe the person to help you with your bills could be the person who services your boiler every year or come round occasionally to solve a heating or plumbing issue. As a charted heating professional and plumber who's studied heat loss and design criteria I believe I have some pointers which can help save energy. Some of them are technical, so you will not find these in the usual websites but they may be worth raising with your heating professional. Why not pay for an hour of consulting, it could save you hundreds every year? I highly recommend you find a technical heating engineer or other professional to do this, especially if you own a larger property, or rent. If you're in a studio or a one or two bed flat you might not see the need after reading my suggestions. Check if your heating engineer or whoever you contract has a thermal imaging camera.
Heat Loss.
This is the one you probably can't do too much about too quickly but is the most significant.
When I carry out heating calculations in an insulated house verses a single brick sash window period property I can see the difference in heat loss is vast. I can calculate equivalent sized rooms to need twice/half the heat output. That could mean having a radiator twice the size, and it will mean spending twice the amount of money to heat each room. Radiators in new build are tiny compared to what you'll see in Edwardian properties. Heat loss, which is really heat waste in a period property will be by far the biggest waste of energy. Conservation area regulations, high costs and disruption to living are the inhibiting factors to investment. If the U.K is to cut out gas boilers and net zero emissions, then building insulation is going to have to be drastically improved in older housing stock. Insulating the loft is the low hanging fruit, thereafter costs and disruption are high. Though higher costs windows can be changed without major disruption. That just leaves the walls and floors where upgrades may and should be done when renovating, this is where EPC's are useful. Property buyers can contrast improved properties and they will have more valve, another return on investment.
Heating; Heating Controls
Your heating needs to be controlled. You can have too much control but too little and you're overheating your home and wasting money. I still find properties without a room stat, the most basic way to control heat. Standard radiator valves only control flow, all your radiators should have thermostatic valves, except rooms where room stats are located. If viable, each floor of radiators should have it's own room stat. This is now mandatory but not retrospectively. Underfloor heating systems should have a room stat in each zone. Some manufactures also have additional sensors that can be placed across a room to calculate average temperature, very useful if your stat is hard wired but may not be well positioned. Smart stats and valves can be linked to various apps to allow greater control and heat load anticipation. A modern efficient system must have comprehensive controls.
Boiler Controls
Your flow rate temperatures can be lowered, and your boiler settings can be altered. Making alterations to boiler settings may cause unforeseen issues such as unsatisfactory output and only a competent person who has read the user manual should make any adjustments to the user controls. Any adjustments to settings should only be made by qualified gas engineers. Aluminium boiler heat exchanges should be cleaned annually.
Heating Temperature Settings
This one's simple and important. Turn down your heating to the lowest comfortable setting. Save money and the planet, you don't need 22c indoor heating while your in a t-shirt. You shouldn't have to wear a jacket indoors either, try wearing a jumper and setting the heating at around 18 or lower if you're comfortable.
Ideal room temperatures source; Vaillant
Can your rooms be sub ideal? Everyone is different and you may need to test this yourself. Health needs should not be compromised based on any money/energy saving advice.
Boiler Age;
Older non condensing boilers should be replaced. More or less the older your boiler the less efficient it is.
Conventional/older boilers have a Sedbuk rating from around 66-81% efficient, while condensing boilers are between 85% and 91% efficient (SAP 2005), Vaillant boiler being installed in 2022 are 91% efficient. You may find your boiler rating on a sticker on the boiler or with the manual. If not your heating professional can investigate for you alternatively you can find ratings on the Sedbuk site https://www.ncm-pcdb.org.uk/sap/ you will need to know the make and model.
Boiler Alternatives
Direct electric space heating or hot water heating is still significantly more expensive than gas.
However heat pumps can operate at similar costs as they take heat from renewable sources therefore an air source heat pump is a well designed system be operate at 300 to 400% efficiency. Assuming for this example 300% efficiency 1 KWh of electric heating producing 3KWh of heating, will need to be contrasted in price to 3KWh of gas heating making a small saving on today's prices. Gas to electric comparisons are set to vary, gas being a finite resource presumable gas will be going up faster than electricity I'm personally working slowly towards gas free energy supply in my own home.
Underfloor heating is ideal for the lower temperatures heat pumps produce compares to gas or other fossil fuels. Radiators should be sized 40% larger than they should be sized for gas boiler heating. Do not assume existing radiators are correctly sized, especially if heat loss mitigation - insulation has been added, or other variables, e.g. extensions added reducing external walls. Consult a heating professional for accurate heat loss calculations.
An electric boiler capable of instantaneous hot water is usually difficult to install retrospectively as the electrical capacity for a residential unit is limited.
Hot Water
The volume of hot water you use the the temperature of the hot water determine the amount of energy you are using. Demand can be reduced by lowering flow rates using existing valve, fitting aerators to taps and changing shower heads. If you do not store hot water you can simply lower your hot water temperature (e.g. combination boiler), with stored water legionella control must be considered and a heating professional should be consulted.
Make sure hot water pipes are lagged.
In larger systems hot water return circuits should be controlled and when practical installed.
Thermal Imaging Cameras
Your heating professional may be able to offer this service. Check internal areas e.g. around windows for lower temperatures to find gaps and cracks. Check external surface temperatures to identify areas of major heat loss. This test needs to be carried out with the heating on and the desired internal temperatures above the external temperature.
Heating System Condition.
Heating systems should be clean of iron oxides (sludge) and clear. Filters should be cleaned (installed if viable) and systems clear of turbidity and of the correct pH.
Heating System Design, Use and Misuse
Radiators should be sized and positioned correctly and controlled.
Underfloor heating should not be covered by high tog rugs.
Radiators should not be obstructed by furniture they reply on convection currents.
Frequent and significant internal temperate changes can cause issues such as condensation.
Air change is important for ventilation, excessive sir change will lead to undue heat loss.
Temperature settings are vital for efficiency.
Correct controls and improved controls will aid efficiency significantly.
Make sure heating pipes are lagged.
Dishwashers Vs Hand Washing Dishes.
As per BBC radio 4's More or Less ; https://www.bbc.co.uk/sounds/play/m000zkzq (skip to 20 minutes in). Using the dishwasher is more efficient than than hand washing. When rising use cold water if practical to save than heating/hot water energy. Around 13 items in the dishwasher and it become waste efficient compared to hand washing, however the dishwasher should be fully loaded/used once a day.
Worth listening to the BBC Radio 4 podcast, it reflects the usual complexities that actually applies to all this advice, which humans do not want usually want to hear.
Hope that helps for now, please add any questions or suggestions you might have as this is a work in progress.
Jeff Culkin
MCIPHE RP RHP