How to Size Heat Recovery Ventilation System

To size a heat recovery ventilation system, you must conduct a full airflow calculation of the dwelling. This calculation must result in at least 0.3 litres per second per metre squared of floor, as this is the minimum required airflow in accordance with Part F of UK building regulations.

As a result of this, you can then select a MVHR unit, and appropriate ducting that can deliver the airflow requirement.

But what does that mean? What is the reason for it?

Put simply, ‘sizing’ a heat recovery ventilation system, is the process of selecting the correct MVHR system and ducting for a dwelling. With MVHR, there is no ‘one size fits all’ method of application.

If you end up with a MVHR unit that is too small, you may struggle to get the appropriate airflow into the dwelling. Whereas, if your unit is too big for the dwelling, you may find that you are getting the results, but at the cost of paying more than you realistically needed to.

Who can size a heat recovery ventilation system?

It is advised to consult somebody who is a HVAC contractor. This is someone who can be  well versed in not only installing MVHR, but picking the right one, with the complimentary ducting, for the dwelling.

You can go to your local builder, who could definitely install it, but without the expertise of a HVAC contractor, your MVHR system may not work as effectively as it should.

What is MVHR commissioning?

MVHR commissioning is the process of having your MVHR system tested to ensure it is balanced. MVHR systems operate differently depending on the dwelling they are placed in, as well as the size of the rooms and more, which is why commissioning is required.

MVHR commissioning can be carried out by HVAC contractors.

How much are heat recovery ventilation systems?

The cost of MVHR systems vary between the type of MVHR unit you need. Naturally, single-room units will cost less than whole-house units. Our range of MVHR units begin at £262, all the way to £2895.

Below we will share some information on our most cost-effective single room, and whole house units. You can click here to view our full range of MVHR units.

Single room unit – Kair Heat Recovery Extractor Fan – 12VAC SELV – Humidistat

At £299.94 The Kair Single Room Heat Recovery Ventilator is perfect for you if you are looking to solve a damp problem in one of your rooms. Such as your kitchen, bathroom, utility room, living room, lavatory, washroom, conservatories, office, and bedroom.

The unit also offers continuous trickle ventilation, meaning it will constantly clean and purify the air you breathe. Continuous ventilation is key to keeping your home mould free.

Nuaire Mrxboxab-ECO3 High Duty Wall Mounted Heat Recovery Ventilation Unit With Bypass And Integral Humidistat

At £2,138.40 , This whole house unit provides the most effective, balanced supply and mechanical extract ventilation with heat recovery, with an automatic summer bypass as standard. 

This unit recovers up to 95% of heat which would otherwise be wasted, whilst also reducing power consumption. The unit is an ultra-quiet unit with a long life motor, which makes for low running and operating costs, straightforward maintenance and years of trouble-free operation.

Purchase a Heat recovery ventilation system today