Internal wall insulation may involve fitting rigid insulation boards to the inside surface of the wall, building an additional stud wall filled in with insulation material such as mineral wool fibre, or sometimes by spraying foam insulation directly onto the inside surface of the wall.
Internal insulation:
• Is generally cheaper to install than external wall insulation.
• Will slightly reduce the floor area of any rooms in which it is applied (the thickness of the insulation is typically around 100mm).
• Can be quite disruptive but can be done room by room.
• Requires internal fittings to be removed and reattached and may require modifications to window and door frames.
• Can make it hard to fix heavy items to inside walls – although special fixings are available.
• Cannot be done before fixing any problems with penetrating or rising damp.
External wall insulation involves fixing a layer of insulation material to the wall, then covering it with a special type of render (plasterwork) or cladding.
The finish can be adapted to fit in with the general look of the building, or with other nearby buildings.
External insulation:
• Can be applied without disruption to your organisation.
• Will not reduce the floor area of your workplace.
• Will renew the appearance of outer walls.
• Will improve weatherproofing and sound resistance.
• Reduces the risk of condensation on internal walls.
• Best installed at the same time as external refurbishment work to reduce the cost.
• May need planning permission – check with your local council.
• Requires good access to the outer walls.
• Not recommended if the outer walls are structurally unsound and cannot be repaired.
The thermal performance of windows and doors cannot be improved by adding a layer of insulation, but you can often make considerable saving by replacing old, single glazed windows and insubstantial external doors with newer, more efficient alternatives. The cost is generally higher than other insulation options, so the expenditure is often not recovered through energy bill savings alone. However, the additional benefits of comfort, improved appearance and reduced maintenance may make the investment worthwhile. If replacement is not allowed due to planning restrictions, or is too costly to justify the expenditure, then secondary glazing may be an alternative. This involves adding an additional layer of glass or polycarbonate to the inside of an existing window, trapping an insulating layer of air without the need to replace the window.
When considering modification or replacement of glazing it is worth remembering that, in an office environment, glare and overheating are often just as significant issues as heat loss. Adding shading, blinds and anti-glare coatings may be of more benefit to the occupants or may be useful additional measures to consider as well as any actions you take to reduce heat loss.
Alongside the installation an air source heat pump and renewables, the Acharacle Community Centre installed loft insulation and insulation in one of the largest rooms (lowering the ceiling and adding insulation above the panel boards).
If you’re looking to reduce the carbon emissions associated with heating or cooling your building, then a heat pump could be a good option. However, it’s important to understand the different types of heat pumps, their applications, financial aspects, and ongoing operational and maintenance requirements. This knowledge can help you to decide when to choose heat pumps as an option for heating and ensures that the systems are installed and operated efficiently.
A heat pump works by taking heat from one location, raising the heat’s temperature, and moving the heat to another spot. A fridge works in a similar way. It takes heat from inside the fridge, moves it to the grill at the back of the fridge, and eventually releases that heat into the kitchen or room where the fridge is placed. When used to heat a building, the heat pump gathers heat from the outdoor air or ground, then brings it indoors to warm up the rooms using either a system of circulating water or air.
A heat pump uses electricity to collect heat energy, raise its temperature and pump that heat indoors, but the heat energy it supplies is much more than the electrical energy needed to power the system.
This makes heat pumps a more energy efficient way to heat a building than a traditional gas or oil boiler. It also produces far fewer carbon emissions than other heating systems.
There is a wide range of heat pump technology available. An experienced heating, ventilation and air conditioning (HVAC) engineer is best able to advise on what is right for your building following a site survey. However, there are some key questions to answer to help you and your HVAC engineer determine whether a heat pump might be suitable, and if so, which kind.
An air-to-water heat pump transfers heat from the outside air to water.
This heated water can heat water circulating your building via radiators or underfloor heating. It can also heat water stored in a hot water cylinder for showers and hot water taps.
Air-to-air heat pumps transfer heat from the outside air, warming air that enters your building through a series of fan coil units, or ‘blowers’, or via ducted air.
Air-to-air heat pumps are sometimes referred to as air conditioning. While many people think of air conditioning as a way of cooling buildings, it can also be used for heating.
If you have the space, then you can have a ground loop system. The ground will need to be suitable for digging and accessible to machinery from a road entrance.
The area will need to avoid trees, as roots will cause problems when digging trenches.
The length of ground loop and trenches depend on the size of your building and the amount of heat you need.
If space is limited, it may be possible to drill vertical boreholes to gather heat. This is usually more expensive than digging trenches and usually needs a specialist ground (thermogeological) survey. The ground is generally warmer the deeper you dig, so these systems can be more efficient than ground loop systems.
Commercial buildings may require more than one borehole. A borehole is drilled only about 20cm wide, but somewhere between 75 and 200 metres deep. The depth of the borehole depends on your heat demand and the underlying geology.
Duns Swimming Pool in Langtongate, Duns installed two air source heat pumps after receiving funding from the Scottish Borders Council. The new heating system and solar panels supply enough power for its heating and reduce the amount of gas needed to heat the pool’s water. Still, gas may be required to top up water temperatures during the winter months.
St Ninian’s RC Parish Church in Dundee replaced its gas boilers with air source heat pumps alongside other improvements, including LED lighting, cavity wall and underfloor insulation. The savings achieved contribute to running costs for the community café that is open to the local community twice a week and where around 20-25 people attend for a free hot meal.
The Roy Bridge School House is a volunteer run community facility providing a vital space for local youth groups, lunch clubs, meetings and workshops. A new heating system – an air source heat pump – was installed in the schoolhouse building to ensure that the building was well heated and would meet the required standards for public use. This allowed the space to once again be used all year round. The project aimed to install a new air source heat pump system which could be connected to the building’s existing underfloor heating system.
Findon Hall replaced the boiler with an air-to-air heat pump and installed solar PV panels on its south facing roof to generate electricity. These measures were estimated to save the Hall’s management committee £6,628 in energy costs, 45,209 kWhs in energy, and 9.5 tonnes of C02 a year.
