Why Does Cotswold Heating Solutions Choose radTherm® and Sunamp Over An Air Source Heat Pump?
At Cotswold Heating Solutions Ltd, we get asked the same question almost every week: “With so many heating technologies on the market, why do you advocate radTherm® electric radiators and Sunamp heat batteries instead of an air source heat pump”?
It’s a fair question. Homeowners across Gloucestershire and the wider Cotswolds are bombarded with grant schemes, glossy brochures, and well-meaning advice from every direction, and it can be genuinely difficult to know which route actually suits a period cottage, a converted barn, or a stone-built farmhouse. We don’t recommend radTherm® and Sunamp because they’re the newest or the trendiest option on the market. We recommend them because, time and again, they turn out to be the most practical, cost-effective, and low-hassle solution for the kinds of properties we work on every day. Here’s why.
The Broader Housing Challenge
Before comparing technologies, it’s worth being honest about the housing stock we’re dealing with. A huge proportion of homes in this part of the country are older properties – listed buildings, stone cottages with thick solid walls, thatched roofs, timber-framed barns that have been lovingly converted. These are beautiful homes, but they were never necessarily designed with modern central heating in mind.
That matters enormously when you’re choosing a heating system, because the technology that works brilliantly in a new-build estate house with cavity wall insulation and underfloor heating often struggles – or becomes prohibitively expensive to install – in a 300-year-old cottage with solid stone walls and no room for a plant room. This is the lens through which we evaluate every heating technology, and it’s why radTherm® and Sunamp consistently come out on top for our customers.
Why Not an Air Source Heat Pump?
Air source heat pumps get a lot of attention, and for good reason – in the right property, they’re an excellent, efficient technology. But “the right property” is doing a lot of work in that sentence, and it’s where a lot of installers gloss over the details.
Heat pumps need a well-insulated, well-sealed building envelope to perform efficiently. They work by extracting relatively low-grade heat from the outside air and raising it to a temperature suitable for your home, typically delivering that heat at lower flow temperatures than a traditional gas boiler. This means they’re most efficient when paired with underfloor heating or oversized radiators, and when heat loss from the building is minimised. In a solid-wall period property without significant insulation upgrades, a heat pump often has to work much harder to maintain comfortable temperatures, which erodes the efficiency gains that make heat pumps attractive in the first place.
The upheaval can be substantial. Retrofitting a heat pump properly into an older home frequently means replacing radiators with larger units, sometimes adding underfloor heating, upgrading pipework, and finding space outside for an external unit – which can be a real challenge on a listed building or in a conservation area where planning restrictions apply. For many of our customers, that level of disruption to a home they love simply isn’t something they want to take on, particularly when the property is aesthetically sensitive.
Upfront costs and payback periods can be difficult to justify. Even with government incentives such as the Boiler Upgrade Scheme, the installation costs for a heat pump system in an older property – once you factor in the necessary insulation and heat-emitter upgrades, costs can run considerably higher than alternative technologies. For homeowners who aren’t planning to stay in a property for decades, or who simply want a straightforward, reliable upgrade, that payback horizon can be hard to swallow.
Planning permission and conservation constraints. A great many of the properties we work on sit within the Cotswolds Area of Outstanding Natural Beauty, in conservation areas, or are listed buildings in their own right. Positioning an external heat pump unit without disrupting the character of the property, or getting permission to do so at all, can be a genuine sticking point that simply doesn’t arise with an internal, wall-mounted radiator system.
None of this means heat pumps are a bad technology – they’re not. But they are a technology that rewards a certain type of property, and we’d rather be honest with a customer up front than sell them a system that will underperform and leave them disappointed.
The Case for radTherm® Electric Radiators
This is where radTherm® earns its place as our default recommendation for room-by-room electric heating.
Minimal disruption, maximum flexibility. RadTherm radiators are dry, self-contained units that mount straight onto a wall and plug into the electrical supply – there’s no pipework, no plant room, no wet system to install or maintain. For a period property where lifting floorboards or chasing out stone walls is either impractical or something the homeowner simply doesn’t want to do, this is transformative. We can typically fit a whole-house system in a fraction of the time a wet system would take, with far less mess and disturbance to the fabric of the building.
Room-by-room control. Because each radTherm unit is independently controlled, every room can be heated to exactly the temperature that room needs, exactly when it’s needed. A guest bedroom that’s rarely used doesn’t need to be heated to the same schedule as the kitchen or living room. This zoned approach avoids the “all or nothing” inefficiency of a central wet system, where you’re often heating the whole house to warm the one room you’re actually using.
High thermal mass for steady, comfortable heat. RadTherm® radiators use a ceramic core with high thermal mass, meaning they store heat and release it gradually and evenly, rather than the sharp on-off cycling and uneven heat you get from some cheaper panel heaters. The result is a background warmth that feels closer to a traditional radiator system than people typically expect from electric heating.
No servicing, no safety certificates, no ongoing maintenance costs. There’s no combustion happening anywhere in the building, no flue to maintain, and no annual boiler service required. For homeowners tired of the recurring cost and hassle of servicing a gas or oil boiler, this is a genuine, ongoing saving – both in money and in mental load.
Suitability for listed and conservation properties. Because there’s no external unit, no flue, and minimal fixing required, radTherm® installations are far less likely to run into planning or conservation objections than an air source heat pump or a new flue for a boiler.
The Case for Sunamp Heat Batteries
Hot water is a separate challenge from space heating, and it’s one that too many “whole system” conversations skate over. This is where Sunamp heat batteries come in.
- A genuinely different way of storing energy. Rather than storing hot water in a traditional cylinder – which loses heat over time and takes up considerable space, Sunamp heat batteries use phase change material to store thermal energy far more densely and with much lower standing losses. A Sunamp unit can be significantly smaller than an equivalent hot water cylinder, which matters a great deal in period properties where airing cupboards and plant space are often at a premium.
- Compatibility with cheap, off-peak electricity. A Sunamp heat battery can be charged overnight using a cheaper electricity tariff, storing that energy ready to deliver hot water on demand throughout the day. This is one of the most compelling arguments in favour of the radTherm®-plus-Sunamp combination: it allows homeowners to shift the bulk of their electricity use to off-peak hours, meaningfully reducing running costs.
- Instant, mains-pressure hot water on demand. Unlike a traditional cylinder, which can run out of stored hot water after a couple of showers, a Sunamp heat battery delivers hot water via a heat exchanger at mains pressure, essentially on demand, for as long as the stored energy lasts – which is comfortably enough for daily use.
- A natural partner for renewables. For customers who have, or are considering, solar PV, a Sunamp heat battery is an excellent way to make use of surplus daytime generation, storing that “free” energy as hot water rather than exporting it back to the grid for a fraction of its value.
- Compact and flexible installation Because Sunamp units are so much smaller than an equivalent hot water cylinder, they open up airing cupboard space that would otherwise be lost, which is often a real practical win in smaller Cotswold cottages where every cupboard counts.
Bringing It Together
What we like about the radTherm® and Sunamp combination isn’t any single feature in isolation, but how well the two technologies complement each other, and how well that pairing suits the properties we actually work on. Together, they offer:
- Low-disruption installation, ideal for listed buildings, conservation areas, and homes where residents don’t want months of building work.
- Room-by-room control for space heating, avoiding the inefficiency of heating a whole house uniformly.
- Compact, efficient hot water storage that frees up space and delivers water on demand.
- The ability to take advantage of cheap, off-peak electricity tariffs for both space heating and hot water, keeping running costs in check.
- No flues, no combustion, no annual servicing, and far fewer planning hurdles than the alternatives.
- A system that scales sensibly, whether you’re heating a two-bedroom cottage or a larger converted barn.
We’re not against heat pumps as a technology – in the right home, they can be excellent choices, and we’ll always give you an honest assessment of what will genuinely work best for your property. But for the majority of the period homes, cottages, and characterful properties we’re called out to across the Cotswolds, radTherm® electric radiators and Sunamp heat batteries consistently deliver the best combination of low disruption, controllable running costs, and long-term reliability.
If you’d like to talk through what would work best for your home, get in touch with Cotswold Heating Solutions Ltd. We’re always happy to visit, take a proper look at your property, and give you a straightforward, honest recommendation – not just a sales pitch.