Cleaner Energy Options
We are all trying to reduce our carbon footprint, heating buildings accounts for 20% of the UK’s emissions so there is a huge potential to reduce these emissions in both commercial and domestic properties. There are many options available and we are here to guide you through these to ensure that once installed it will meet your expectations.
Over the last few years a number of technologies have been in favour only to be proved in time not to meet the anticipations from when they were installed. Today with the new Building Regulations a number of technologies have become more attractive. Heat pumps are now seen as a significant heating plant that will help reduce carbon emissions and energy use in supplying heating and helping with hot water. The tools to calculate energy use in buildings known as SAP10 and SAP10.1 (Standard Assessment Procedure) now favour electrical heating over other fuels, even gas. New domestic houses will be all electric from 2025. The primary issue is that electricity is about four times the price of natural gas and is likely to stay that way for the foreseeable future.
We look at each property that is requesting alternative heat sources to evaluate the more energy efficient equipment that will meet both install costs and running costs.
Over the last twenty years heat pumps have become more efficient and are an excellent energy source for low temperature circuits and hot water pre-heating. The two most common options are ground source heat pumps (GSHP) and air source heat pumps (ASHP). Ground source remove heat from the ground, raises the temperature and distributes the heat into the building, they also have the ability to reverse that by removing heat from the building and dumping it back into the ground.
Air Source operate in the same way but take heat from the air instead and can be reversable too to cool a building in Summer.
Why Heat Pumps?
The advantage of heat pumps is that for every kW put into the unit you get more heat out, this can range from 1.1:1 to 7:1 and even higher in some circumstances. This means that a careful evaluation of every property has to be carried out before deciding if it will be the best solution for the future.
GSHP are expensive as they need significant land area or deep bores to get the enough ground to gain the heat, they will need 50-80 metres of pipe per kilowatt (kW), or 10 metres of ‘slinky’ coiled pipe per kW, with at least 5 metre distance between trenches with coils, and ideally 2m deep. The cost will be between £2-4,000 per kW depending on the ground conditions.
ASHP are installed outside with fan units passing the air over coils to extract the heat. These can be large units as size will help to minimise noise, this will mean positioning can be an issue. As the efficiency rises with air temperature and lower the heating temperature, they are more efficient with low temperature emitters like underfloor heating. ASHP are much cheaper and less disruptive to install than GSHP but are not as efficient. As the air coils on the ASHP require defrosting every so often and can only start and stop a maximum ten times an hour they require buffer vessels, these will need to be 15-25 litres per kW of heat pump.
If temperatures of the heating system is required over 50-55⁰C then a hybrid system will be the most efficient solution with Ultra low NOx gas condensing boilers being used for peak load and the higher temperatures when the heat pump is least efficient.
Hybrid Heating Systems
As building regulation are tightened and building energy calculations are tightened all new buildings will be electrically heated using an