MVHR and building physics knowledge for healthy, comfortable and energy efficient homes
As much as 25% of the heat loss of a building is via air leakages in the building fabric (ie, draughts). The airtightness of the building fabric is therefore an important metric to measure and improve as much as possible when building or renovating a home. Equally, a more airtight building also improves comfort, acoustics … Read more
It is subtle and understated in its impact on UK housing, but this new build bungalow home is one of the most energy efficient buildings in the world – and represents the future of housebuilding in the UK and Europe. We pressure tested the home this December using a calibrated airtightness testing fan and it … Read more
If you’re researching installing a Mechanical Ventilation with Heat Recovery (MVHR) system for your project, you may have heard of an Enthalpy heat exchanger or ERV (Energy Recovery Ventilation). But what is an “Enthalpy” heat exchanger? How does it change humidity in the home? And is it expensive to install? The basics of enthalpy heat … Read more
I’ve written before about the average price of a high quality Mechanical Ventilation Heat Recovery (MVHR) installation, which includes an itemised price for each detailed ductwork layout, materials supply, installation and commissioning (airflow balancing and client handover). Today I’m going to explain (with photos) why the cheaper MVHR units are a false economy, and can … Read more
30 years ago house-builders in the UK would have never considered how airtight they were building new homes. “Aren’t all homes fairly airtight, once you put the windows and doors in and pump the gaps with insulating foam?” Well, not necessarily. Fireplaces used to be for both heating and ventilation Traditionally, homes built before our … Read more
The most common question I’m asked by people interested in mechanical ventilation with heat recovery (MVHR), low energy building design or Passivhaus is: How much space do we need for the ducts in an MVHR ventilation system? Variations to the question include: How big is the MVHR unit itself? How big are the ducts? Will … Read more
Building Regulations Part F wants to know how much air (in m3hr) passes through each metre square area of the fabric (m2). This is the Air Permeability (AP or m3.hr/m2) figure of the building. To get the AP figure, one calculates the volume of air in the property. Then one calculates the total external envelope … Read more
If you would like to learn more about what’s involved during a building airtightness test in the UK, please read on. If you have a new build project or renovated building which requires an airtightness test for any reason, please contact me on Patrick [@] Heatspaceandlight.com for pricing. Any new build in the UK has … Read more