A Mechanical Ventilation with Heat Recovery (MVHR) system is a great way to improve the indoor air quality of your home. They work by extracting stale, humid air from your home and replacing it with fresh, filtered air from outside. MVHR systems can also help to reduce your energy bills by recovering heat from the outgoing air and using it to warm the incoming air.
However, mechanical ventilation with heat recovery can be expensive to install, so it is important to know how to design a MVHR system correctly to ensure that they are effective and efficient. For example, if a system is under sized and is running to near capacity this can result in:
- Poor indoor air quality because the ideal airflows cannot be achieved
- Noise issues due to inadequate ducting causing high static pressure
- Reduced efficiency which costs you more money to run
- Shorter lifespan because the system is working extra hard, all of the time
- Ineffective humidity control which could cause mold or damp issues
- Not meeting Part F of Building Regulations
Oversized systems will still operate efficiently but being a larger unit, the upfront purchase costs will be unnecessarily higher.
The correct way to design a Mechanical Heat Recovery Ventilation (MVHR) system
It’s important to have your MVHR system designed correctly by a competent ventilation designer or expert but here are some tips to ensure all the right things are considered to help you avoid those unnecessary issues caused by poor design and installation.
1. Calculate the required airflow rates.
The first step in designing a MVHR system is to know the required airflow rates for your home. This will depend on the size of your home and the total number of wet rooms. MVHR systems need to be balanced, meaning the total amount of air being extracted from the wet rooms and supplied to the habitable rooms must be the same.
2. Design the ductwork system.
The ductwork system is responsible for distributing the fresh air throughout your home and extracting the stale air. It is the key component to ensuring the whole system runs efficiently and effectively. The ductwork system should be as short and straight as possible, and it should be insulated to prevent heat loss. An important factor to consider in choosing your ductwork is knowing the anticipated static pressure it will produce. You ideally want to aim for a static pressure of no more than 100pa. (The bigger the duct, the less static pressure).
3. Choose the right MVHR unit.
Once the required airflow rates and the anticipated static pressure have been determined, it’s much easier to select the right MVHR unit for your home based on the location of installation and the lowest possible energy-consumption. Dantherm have a range of MVHR units for domestic applications, and it is important to choose one that is the right size for your home and that has the features you need to benefit you and your family.
4. Installing the MVHR system.
When the system is ready to be installed, the qualified installer will use the ducting design and manufacturer’s instructions to ensure this is done correctly and inline with all necessary procedures.
5. Commissioning the MVHR system.
When all the building works on your home have been completed and you are ready for your MVHR system to start working, your qualified engineer will commission the unit in accordance with building regulations, the design and the manufacturer’s instructions.
Here are some additional tips for designing a MVHR system:
Consider the location of the MVHR unit. The MVHR unit should be located in a centralised position that provides the best means for connecting and distributing the ductwork throughout your home. The unit must also be easily accessible for maintenance purposes.
Consider the noise level of the MVHR unit. MVHR systems will only be noisy if they have been designed, specified or installed incorrectly. If all the measures above have been adhered to then you should experience no issues with noise. Silencers should be used where appropriate to avoid cross-talk between rooms.
Consider the initial cost of the MVHR system. It is important to factor in all the costs associated with your system including; the ventilation design, the materials of the MVHR system (including any accessories), all required ducting materials, the cost for installation, commission and ongoing yearly servicing. The ongoing annual running costs of a MVHR system are minimal.
By following these tips, you can choose the right MVHR system for your home and design it correctly to ensure that it is effective and efficient. For anyone looking for the BEST MVHR, we highly recommend. Dantherm Climate Control Solutions: Read here to find out why.
MVHR Design Services
We are here to support homeowners and self-builders ventilate right the first time round. We offer a European leading brand of mechanical ventilation with up to 10-years warranty.
We support Heat Recovery installers throughout the UK and have bases in Sheffield, South Yorkshire and East Sussex. We supply Dantherm MVHR within the UK and Ireland and our UK based technical support team is on hand to assist you with the design and specification of your MVHR system. We can even put you in touch with our network of UK based, Dantherm approved installers to ensure the installation and commissioning of your system runs smoothly.
For more information contact us.
