A detached family home in the Cotswolds has recorded a significant drop in radon levels following the installation of our high performance MVHR system.
The home is nestled in an area of outstanding natural beauty, and over the years the homeowner has been improving and renovating the home.
Radon levels dropped by more than half due to MVHR
Our client contacted us one year after the installation of the MVHR system to say that the UK Health Security Agency has reported the radon levels have now dropped to 98 – from a level of 260 that was occurring before adding MVHR.
Our client said that the MVHR had had a dramatic effect and they were very relieved, as other measures to lower radon had been ineffective.
MVHR was installed because the building’s airtightness level improved during the renovation works to the extent it became necessary to increase the indoor ventilation rate for the home, and the best way to do this is via MVHR to increase good air quality, comfort and energy efficiency in the home.
MVHR self-installed by the homeowner with HSL support
The client decided to install the MVHR system themselves as a retrofit but wanted to be guided by a specialist company – which is where HSL helped.
Our client said that HSL’s design guidance and choices, management of the supply process and our phone and email support during the installation were all “first class”.
He said he was very pleased with the system and really impressed with the build quality of the Zehnder MVHR unit at the heart of the system.
Our client added that when there was one minor problem with the unit (it arrived with a faulty pre-heater from the factory) it was sorted it out very efficiently.
MVHR so quiet the occupants can’t hear it
Our client concluded by saying that the only “downside” was that the MVHR system is so quiet that his wife questions whether the system really exists and that his stories of doing some “MVHR work” for the last 6 months were fabrications!
Our client’s review – plus over 20 more 5-star reviews of our MVHR design, supply and commissioning services – are available online on our business page.
![HSL MVHR system uses less than half a kilowatt per day to run](https://www.heatspaceandlight.com/wp-content/uploads/2025/02/HSL-MVHR-system-uses-less-than-half-a-kilowatt-per-day-to-run-2025.jpg)
If you are concerned about radon and/or would like to discuss your own MVHR project please contact us at the top of the page or fill in our free MVHR design tool.
You can also read about how much a high performance MVHR system costs in 2025 here.