Energy
Keeping warm: optimising building performance
Heating is a critical – and expensive – element of running a care home, which is why maintaining an efficient system is so important, as Jeremy Carter of Carter Energy Consulting explains
In care homes, the biggest consumer of energy is heating. Care homes use heat for building comfort and in the provision of hot water. Having audited a number of care homes, I have seen a lot of unnecessary energy waste within heating systems. Typically, care homes will consume and
waste energy within heating in three main ways: n The efficiency of the heat source n The transportation of heat n The thermal efficiency of the building
1. The efficiency of the heat source The first way a care home consumes and wastes energy in heating is through the efficiency of the heat source. I have seen a range of heat sources, from old, inefficient, poorly maintained boilers to state of the art air source heat pumps. Naturally, the efficiency of the heat source will play a dominating factor in the overall heating system efficiency.
So what does ‘heat efficiency’ mean? Heat efficiency relates to the energy input divided by the heat output. In simple terms, a 90 per cent efficient boiler will deliver 90,000 kWh of heat for every 100,000 kWh gas input. An air source heat pump (ASHP) will have a higher efficiency rating than boilers. A standard ASHP will have a seasonal energy efficiency rating (SEER) of 2.4, meaning 240,000 kWh of heat for every 100,000 kWh of electrical input. In simple terms, this means ASHPs are 240 per cent efficient. However, this does come with a caveat.
January 2025
www.thecarehomeenvironment.com
What does ‘seasonal energy efficiency rating’ mean? An ASHP will pull the outside air temperature across a refrigerated coil to generate heat. In doing so, the temperature of the outside air has a direct bearing on system efficiency. This means the system efficiency of an ASHP rises and falls with the ambient air temperature, becoming highly efficient in the summer months and less efficient in the colder months. What we have just described is known
as rated system efficiency. While knowing the rated system efficiency is important, it is worth noting that having an efficient heat source does not necessarily mean an efficient system overall – other factors such as age, controls, and maintenance
I have seen a lot of unnecessary energy waste within heating systems
can have a significant bearing on system performance.
System age
The age of the heat source will have a bearing on system performance, particularly if the asset has not been maintained (see below). Heating technology is developing quickly, meaning a brand new boiler or heat pump will be far more efficient than one that is 10-20 years old. This is due to the advance of heating technology, particularly with ASHPs as more efficient refrigerants are utilised.
Controls / zoning
Controls – and the efficiency thereof – will have a significant bearing on energy consumption. In care homes, heating is typically controlled via a thermostat. The siting of the thermostat is critical to system performance.
A thermostat located close to an external door or open window will record a colder
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