What Is Heat Recovery Ventilation?

What Is Heat Recovery Ventilation

What Is Heat Recovery Ventilation?

With new buildings being made to be as energy efficient as possible, and the UK aiming for 95% of its electricity usage to be low carbon by 2030, we at I-Sells believe as the UK’s leading ducting and ventilation supplier that it is our responsibility to share with you the best energy saving solutions that can keep your home feeling fresh, free from mould and energy efficient. In this article, we will be discussing heat recovery ventilation. But what is heat recovery ventilation?

Heat recovery ventilation (HRV) is the process of extracting indoor stale or moist air and replacing it with filtered fresh air from outside, which is also heated due to the HRV recycling the warmth from the air it was replacing. This is facilitated by a heat recovery ventilator

What is a heat recovery ventilator?


As of 2022 England and Wales scored a D in the latest stats for energy efficiency. (With A being the best and E being the least energy efficient) it is clear to see we still need some help with keeping the heat in our home, and not wasting energy. With heat recovery ventilation being a brilliant option in making your home more energy efficient and free from mould and condensation, it’s only right that we break down every aspect of a heat recovery ventilator.

What does a heat recovery ventilator do?

A heat recovery ventilator facilitates the removal of indoor humid or stale air and replaces it with fresh outdoor air which is also heated by recycling the heat from the indoor extracted air. Along with this, they have the ability to reduce the buildup of condensation, making your home or business less susceptible to mould. The recycling of heat makes them more energy efficient and a good long-term investment to help you save on your energy bills.

How does a heat recovery ventilator work?

I-Sells offers three options when it comes to heat recovery ventilation, single-room, modular and whole-house units.

Depending on your choice, some operate with a pull cord, some operate in the same way an extractor fan would, and some operate via remote. What works best for you is dependent on your needs and home specifications, we encourage you to browse our stock for a good understanding of the solutions we offer.

What is heat recovery ventilation?


A heat recovery ventilation system is what we would categorise as a whole-house unit depending on your choice these systems have the benefit of keeping your whole home energy efficient and warm, let’s take a look at a system suitable for medium-sized houses and apartments as an example.


The Nuaire MRXBOX95AB-WM1 has the ability to commission the supply and extract fans independently at both minimum and maximum speeds. This allows the unit to provide the perfect ventilation for the environment in which it is placed.

This is a medium-duty unit, ideal for small to medium-sized houses and apartments.  It is compact, low profile and simple to install, providing the perfect solution for a wide range of properties.

The MRXBOX95 range of products can recover up to 95% of heat which would normally be wasted, meaning this is a highly efficient product which will attract a high score on SAP Appendix Q and help meet building regulations.  This particular version is fitted with an automatic summer bypass as standard, which provides cooling during the warmer months.

The range is designed to provide an optimised, balanced supply and extract mechanical ventilation with heat recovery, and the MRXBOX95AB-WM1 is ideal for small to medium-sized houses and apartments, as it can be mounted in either a wall or cupboard.  It incorporates the most efficient low-voltage DC fans, a counter-flow heat exchanger and easily accessible controls. Added to extremely low noise levels and minimal maintenance requirements, this is an ideal way to provide effective MVHR new-build properties.


  • Compact, lightweight and easy to install
  • Fan controls designed for quick and easy commissioning
  • Easily accessible filters from the front cover – no tools required
  • Integrated, automatic summer bypass
  • Code 3 or above through SAP Q-eligible products
  • Part F & L building regulation compliant
  • Constant quiet running fans to ensure occupant acceptability
  • Integral frost protection
  • With a 5-year warranty: 1-year parts and labour, remaining years parts only (UK and Ireland only).

Do I need a heat recovery ventilator?

Is heat recovery not the issue for you? When asking yourself this question, it’s a good idea to also ask yourself these questions:

“Is there condensation in the home?”

“Is there mould in the home?”

“Am I really saving energy?”

If you answered yes to either of the first two questions, then the third question will be a no. If you have condensation or mould in your home, you need a heat recovery ventilator.

Condensation occurs when heat and moisture in the air are confined to a certain area, as this heat tries and fails to escape, droplets of water are created on cold surfaces. A good way to think about this is having a hot shower on a cold day and not opening your window.

Condensation if left untreated creates the perfect environment for mould, which if your home is housing, means your current level of ventilation is not sufficient enough. A heat recovery ventilator will aid the removal of humid air whilst retaining the heat from that air, exchanging the moisture with the cold air it brings in from outside. Below, we’ll share an example of a single-room heat ventilator, ideal for a bathroom.

Kair Heat Recovery Extractor Fan – 12VAC SELV – Humidistat

The Kair KHRV150/12RH 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.

This unit is perfectly suited to your needs as it automatically controls the humidity of your room for you, so you can relax knowing that it will take care of everything for you. The unit also offers you continuous trickle ventilation, so it will constantly clean and purify the air you breathe. Continuous ventilation is the key to keeping your home mould free.

The unit is highly energy efficient so it will help you save money on your heating bill. Up to 86% heat recovered from extracted air, means even in cold winter weather the incoming clean air will remain at almost the same room temperature.

The unit is 100% completely safe for you to put in your bedroom or your child’s bedroom since it has a very low voltage. By providing adequate ventilation the unit maintains the recommended humidity levels, preventing harmful bacteria from being breathed in.

How much is a heat recovery ventilator


As we offer a range of HRV units, varying from a single-room to whole-house, the price of the ventilators fluctuates but we offer competitive and affordable prices. Heat recovery ventilators are investments for your future and your health. Let us share with you an example of our affordable heat recovery units, at only £238.93

Vent Axia Lo-Carbon Tempra P Heat Recovery Unit (443312)

The Vent Axia Lo-Carbon Tempra P Heat Recovery Unit (443312) is available with pullcord control, timer control or humidistat, timer and pullcord. All models are also available in SELV (Safety Extra Low Voltage).

Low energy consumption means the Tempra exceeds the energy-saving requirements in Part L, Conservation of Fuel and Power. With several optimisation options available to adjust the fan speed.

The units are fitted with a 24V ECDC motor with a state-of-the-art built-in power supply. This has the ability to operate at only 2 Watts power consumption on normal setting, offering a 90% energy saving over conventional AC equivalents

Apart from removing odours, providing fresh air and recovering heat, this appliance extracts airborne impurities such as dust, dirt and grease. These gradually build up and detract from the efficiency and appearance of the appliance. To ensure peak performance, the heat exchanger should be cleaned as required in accordance with the instructions supplied.

Is a heat recovery ventilator worth it?

If you believe in having a fresh feeling, mould-free, and condensation-free, home then a heat recovery ventilator is worth it.

At I-Sells we genuinely believe that any investment that helps better your quality of life through our basic necessity – fresh air, is always worth it. With ranges in units and prices, browsing our stock to find the right heat recovery ventilator is the first step in making your home feel fresh, comfortable and energy efficient.

Here to help your home

We at I-Sells endeavour to make sure our customers have all the information they need before making the choice to invest in our products. Be sure to visit our blog page to gain knowledge on the wide array of factors and issues surrounding ventilation, mould, condensation, and much more.

We hope to have helped you by answering the question ‘what is heat recovery ventilation?’

We understand you may have more questions, Please do not hesitate to contact us for more information with regards to heat recovery ventilation. If you’d like to send us an email, click here. For other contact options, see below:

Call us on 020 8463 9696

Visit us at our showroom:


Monday – Friday: 8:00am to 17:30pm
Saturday: 9:00am to 12:00pm
Sunday: Closed

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DA14 6ES
United Kingdom

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