FAQ
Choosing the right renewable heating system is a big decision and it’s completely normal to have questions. Whether you’re exploring heat pumps, solar PV, battery storage, MVHR, or underfloor heating, our goal is to give you clear, honest answers that help you understand your options and feel confident in your choices.
This FAQ page brings together the questions we’re asked most often by homeowners across the UK. It covers everything from system performance and running costs to installation timelines, maintenance, and compatibility with other technologies. No jargon, no sales pressure just straightforward guidance from a team that installs these systems every day.
If you don’t see your question here, or you’d like tailored advice for your home, our team is always happy to help. Renewable heating is a long‑term investment, and we’re here to support you at every step.
Air Source Heat Pumps
An ASHP extracts heat from the outdoor air and upgrades it via a refrigerant cycle to provide heating and hot water. Modern units typically deliver around 3 units of heat for every 1 unit of electricity used
Air passes over an evaporator coil, the refrigerant absorbs heat, is compressed to raise its temperature, and then transfers that heat into your radiators, underfloor heating, or hot water cylinder.
Yes. Standard units operate down to –15°C, and enhanced‑vapour‑injection (EVI) models down to –25°C. Even at –15°C, a good unit can still achieve a COP near 2.
Most domestic units declare 50–65 dB(A) sound power. Correct siting and MCS noise calculations ensure compliance with permitted development limits (e.g., 37 dB LAeq,5min at neighbour assessment points in England).
Ground Source Heat Pumps
A GSHP extracts heat from the ground using buried pipework (ground loops or boreholes). The ground stays at a stable 8–12°C year‑round, giving GSHPs very high efficiency and consistent performance.
A water‑antifreeze mix circulates through pipes in the ground, absorbing low‑grade heat. The heat pump compresses and upgrades this heat to provide space heating and hot water. GSHPs typically achieve SCOP values of 3.5–5.0, higher than most air source systems.
Horizontal loops — trenches 1–2m deep; require large garden space.
Vertical boreholes — drilled 60–150m deep; ideal for smaller plots or higher heat loads.
Slinky loops — coiled pipework used in trenches to increase pipe density
Yes. Ground temperature remains relatively constant throughout winter, so GSHPs maintain high efficiency even during freezing conditions.
Solar PV
Yes. Solar panels generate electricity from daylight, not heat. They work year‑round, including cloudy days and winter. Output is lower in winter but still meaningful.
Yes. Panels still generate electricity from diffuse light, typically producing 10–25% of peak output depending on cloud thickness.
Yes. Winter output is lower due to shorter days and lower sun angles, producing roughly 30–40% of summer output.
No. South is ideal, but east and west roofs produce only around 15% less and are still highly viable. Shading matters more than direction.
Battery Energy Storage System
A battery energy storage system stores excess electricity — usually from solar PV or off‑peak tariffs — and releases it when your home needs it. This reduces grid reliance and increases self‑consumption of solar energy.
Most modern lithium batteries last 10–15 years or 4,000–6,000 cycles, depending on depth of discharge and usage. Many manufacturers offer 10‑year warranties.
No. Batteries can operate without solar PV by charging from off‑peak electricity and discharging during peak periods. However, solar + battery offers the greatest savings.
Yes — modern lithium iron phosphate (LFP) batteries are extremely safe and widely used. Safety features include:
Battery Management Systems (BMS)
Thermal monitoring
Over‑current and over‑voltage protection Correct installation is essential.
Mechanical Ventilation Heat Recovery
Mechanical Ventilation with Heat Recovery (MVHR) is a whole‑house ventilation system that extracts stale air and supplies fresh filtered air, while recovering up to 90–95% of the heat from the outgoing air. It improves air quality, reduces heat loss, and supports energy‑efficient homes.
MVHR uses two air streams:
Extract air from kitchens, bathrooms, and utility rooms
Supply air to living rooms and bedrooms A heat exchanger transfers warmth from the outgoing air to the incoming fresh air, reducing heating demand.
MVHR reduces heating demand by 10–25% depending on airtightness and climate. Heat recovery efficiency is typically 85–95% for modern units.
MVHR significantly reduces condensation, damp, and mould by providing continuous, balanced ventilation. It is especially effective in bathrooms, kitchens, and bedrooms.
Underfloor Heating
Underfloor heating (UFH) is a low‑temperature heating system that warms your home by circulating warm water through pipes beneath the floor. It provides even, comfortable heat and eliminates the need for radiators.
Yes — UFH is the most efficient partner for heat pumps. Heat pumps work best at low flow temperatures (30–45°C), which UFH is designed for. This maximises efficiency and reduces running costs.
Yes — retrofit systems are available, including:
Low‑profile boards (15–20mm)
Overlay panels
Slimline pipe systems Retrofits may require floor height adjustments or new floor coverings.
Most coverings are compatible:
Tiles and stone (best performance)
Laminate and engineered wood
Vinyl and LVT (check max temperature limits)
Carpet (use low‑tog underlay and carpet)