A Closer Look at Heat Pumps
As we brace ourselves against another cold winter and continually reach for the thermostat, the impact of our own behaviours on the environment is ever more prescient. Where does the energy required to heat our homes come from, and are we using it as efficiently as possible?
With the Green Homes Grant still available to homeowners offering payments of up to £5,000 to go towards installing energy efficient home improvements, now is a great time to look at one of the stand out options for greener heating – heat pumps.
Heat pumps represent the most efficient alternative to fuel, oil and electric systems in regards to both heating and cooling. Gas furnaces do a relatively good job, rated close to 98 per cent efficient, however they do not represent a long term solution in terms of carbon footprint. Heat pumps supply more heating and cooling capacity than the amount of electricity used to run them. Properly designed and installed heat pumps regularly attain more than 300 percent efficiency.
Heat pump prices can be the fly in the ointment when taking into account the installation of the entire system, however the costs will vary for different options. The typical starting price range for a complete installation is around £7,000.00 for air to water systems, while ground source heat pumps are more expensive . The final set up and running costs of heat pumps depend on your household, its insulation properties and size. These running costs are however highly likely to be significantly lower than the ones of previous systems, dependant on what system you are switching from. For instance, if you switch from gas, this will give you the lowest saving figures, while a typical home shifting from electricity could well save more than £500 per year.
So, how do they work?
Heat pumps are essentially systems that move (pump) heat from one place to another by using a compressor and a circulating structure of liquid or gas refrigerant, through which heat is extracted from outside sources and pumped indoors. Pumping the heat uses less electricity compared to when electricity is solely used as a means to convert it, and there is an added bonus that on warmer days the cycle can be reversed and the unit acts like an air conditioner.
When looking at what kind of heat pumps would be best for you and your home or business, there are three terms we need to be aware of:
Coefficient of performance (COP) Seasonal coefficient of performance (SCOP) Seasonal performance factor (SPF)
The higher the number for each of these factors, the more efficient a heat pump is, the less energy it consumes, and the more cost-effective it is to operate. There are several factors that will affect the efficiency of a heat pump, such as auxiliary equipment, technology, size and control system, but also temperature and humidity conditions: the efficiency drops when the temperature difference increases, some heat pumps can therefore struggle in freezing conditions.
What are the different types of heat pumps?
There are three main types of heat pump but they all operate on the same principle of heat transferral, and the and the type best suited to your home or business will likely depend on your home location and surrounding environment. The most common type of heat pump is the air source heat pump, which transfers heat between your house and the outside air. Ground source, water source or geothermal heat pumps achieve higher efficiencies by transferring heat between your house and the ground or nearby water source. Although these are more expensive to install and require sufficient land or a water source for installation, they generally have lower operating costs because they can rely on more constant source temperatures. Some Advantages & Disadvantages to Consider...
Lower running costs
Less maintenance required
Safer than combustion based heating
Reduces carbon emissions
Can provide cool air as well
Longer life span than combustion based heating
High upfront cost (although this can be helped with govt grants and reduced operating costs will lead to long term savings)
Installation difficulties (dependant on type required and local geology)
Questionable Sustainability (some of the fluids used for heat transfer are not biodegradable which raises environmental concerns, but most manufacturers have options for fully biodegradable fluids)
Significant work (installation can require significant work and disruption to your building including holes through walls, and choice of system will depend on local geology)
Cold weather (some heat pumps can struggle in consistently very cold weather, although this can be negated by checking the SPF of the heat pump you want to install)
Planning permission (Wales and NI require planning permission before installation, in England and Scotland it depends on your locations and size of your property)
If the upfront cost and the situation of your home or building lend themselves to installing heat pumps, it’s a great way to reduce your carbon emissions, reduce your running costs, and help the environment. But it is worth keeping in mind that no matter what your main heat source is you should always be looking for ways of retaining and optimizing the heat you create. Double glazing, sealing gaps in doors and windows and insulating heating pipes are some of the many cost-effective methods for reducing your energy bills and carbon emissions. For more information on these methods, heat pumps or any aspect in greening your home or business get in touch with Fifty Shades Greener and we will be happy to discuss your environmental strategy.
Hamish Sherlock Fifty Shades Greener