We Specify Differently

Knowing that the construction industry has patchy knowledge and skills in Domestic Ventilation, we are offering a bespoke service for our customers in terms of MVHR specification, design and project support.

We put ourselves in the shoes of our customers, as we don’t like the usual sell-and-run approach.

We design and specify to, what we deem true best practice standards, derived from the Passive House methodology:

The quiet operation of a system, optimised indoor air quality, minimal heat losses and no-compormise ducting are properties that are applicable to all types of buildings, not just Passive House.

The English, Welsh and Scottish metodology for determining the minimum overall ventilation rates for MVHR systems is based on the floor area and the number of bedrooms (England) or habitable rooms (in Scotland). Then for the indivual rooms the overall rate is split according to the volume of the room. There is no consideration to the use and occupancy of the habitable rooms.

This means that bedrooms and studies end up typically with ventilation rates of 3-8 l/s. In reality this will translate into IAQ levels of 1,250 to 1,600 ppm of CO2, which is a high level of air pollution, according to BS 40102.

1000ppm of CO2 is a long-established benchmark between poor and acceptable IAQ, stemming back to the mid 19th century, by scientist Max von Pettenkofer.

We therefore are not just looking at the regulatory minimum values, but over and above this, we apply a number of best practice considerations, to make sure that the IAQ in critical habitable rooms is good (up to 1000ppm typically).

We consider the use and occupancy of each room, the usage frequency and length, as all of these are important factors for the health and wellbeing of the occupants.

Sadly hardly any other company takes this into consideration.

We charge for our MVHR designs, as we believe that a great service can only be delivered, when we take time to get it right. We listen to your individual requirements and carefully consider your house design, including section drawings and joist layout.

After the draft layout is finished, we will consult with the customer, architect or builder, to make sure the customer gets what he wants and that the system can be installed as such. We are happy to revise the drawing slightly to make it perfect. Up to 5 iterations are included in the design fee.

Our 3d designs are showing the duct runs, duct sizes, components, terminals, insulation, controllers, air flow rates and the MVHR system. We show the plant space in great detail from various angles, as this is the most complex part of the system.