On a sunny day in July, as part of a project set up by the sustainability and innovation charity NESTA, Under One Roof visited a tenement flat in Glasgow to learn about a couple’s experience installing and running a hybrid heat pump in a pre-1919 tenement flat.
Jane and her partner Dave moved into their ground-floor flat in a pre-1919 red sandstone tenement in the Shawlands area around two years ago. With Jane’s background in green energy and ongoing renovations, the couple decided it was time to reduce their gas consumption and switch to a hybrid heat pump.
The hybrid air source heat pump provides heating for the flat, with gas mostly just supplying their hot water. Gas could be used to heat the radiators; however, users are able to keep the heat pump on a setting where this is kept to a minimum to reduce carbon output.
The unit is mounted on the external back wall, raised off the floor.
The installation process, which began last January, took about six weeks, with the heat pump installation itself – replacing radiators, installing new pipework, and fitting the unit – taking just under a week. There were delays due to issues of damp discovered upon removal of the gas boiler as well as suspected staffing issues at the installation company that led to gas engineers, rather than heat pump specialists, installing the pipework.
Unfortunately, the pipework ultimately needed further attention from a heat pump specialist, due to unwanted creaking noises caused by the initial installation; it has been issue-free since.
Jane said the experience reinforced the need for more specific training for heat pump installers and recommends flat owners considering installations of their own insist that they are carried out by qualified heat pump specialists, as although the pipework may seem similar to gas, it is a different system and technology that requires specialist knowledge.
The unit is mounted on the external back wall. Jane and Dave have good relations with their neighbours and have had no noise complaints. They didn’t need to get permission for the installation from their co-owners nor did they need planning permission. However, Jane did point out that other rules may apply to tenements in conservation areas.
They applied for and received grants from Home Energy Scotland for the heat pump and external wall insulation in the front and back walls. Each grant totalled £7,500, covering the total cost of the insulation and three quarters of the heat pump installation costs, which included moving the underfloor pipework to optimise the location of radiators in the property.
Jane said that their hybrid heat pump performed well through last winter, and they haven’t noticed a significant change in their energy bills compared to what they were paying prior to the installation, paying on average £100-£150 a month. Jane noted that they could still make some behavioural changes to lower their energy bills even further.
The heat pump’s lifespan is about 15-20 years, by which point Jane expects it will likely be the equivalent of a VHS tape today – clunky and outdated. She says there’s lots of innovation in this sector, so heat pumps will probably look quite different by the time replacement is needed.
Double glazing was added to the sash and case windows in the living room, and triple-fin radiators were installed to enhance the flat’s energy efficiency.
When renovating a flat, Jane’s advice is to consider installing a heat pump whilst the other work is going on. Other energy-efficient upgrades they made included adding double glazing to sash and case windows, installing triple-fin radiators, and adding underfloor insulation in the form of sisal wool blocks, a natural, breathable form of insulation.
With the move to decarbonise buildings in Scotland, Jane firmly believes that it is possible to preserve and not ruin the look of historic properties whilst also making them greener, less draughty, and able to meet modern energy efficiency standards. She wants to see people working on agreements for greening old buildings in a sensitive way.
Many traditional tenements in Glasgow, and other parts of Scotland, have stood for over a century, and for Jane, and many others, multiple generations have lived in these buildings. She emphasised the need to take care of them and to not let them crumble around us.
If you are interested in finding out more about installing a heat pump in tenement flats, reach out to Home Energy Scotland, where you can also find information on available funding.
If you’d like to Visit a Heat Pump, follow the link below to find a heat pump in your area.
