If you’re building or renovating to energy efficient, high comfort and healthy air quality standards and you and your contractor are working hard to make sure the building fabric is as airtight as possible, you will need mechanical ventilation in order to supply the fresh air you need to keep the air healthy and expel CO2 and other dirty pathogens in your home. Read more about air quality in the home here.
Mechanical Ventilation with Heat Recovery units (MVHR or HRV systems) are the gold standard for supplying air into your home and extracting waste, humid air. Because the highest-quality units recover around 93-96 per cent of the heat you’ve already generated in your home and transfer that heat to the incoming fresh air from outside in winter, they’re also hugely economical.
But there are costs associated with installing an MVHR / HRV system, all of which I’ll run through now. You’ll find estimate pricing below for 2020 prices, but if you want a free MVHR sizing and specification please complete this sixty-second form here and I’ll send you a bespoke quote.
This example, for a medium-sized home of approximately 200m2, is updated for 2020 prices and for the UK market. Please feel free to contact me at Patrick [a] heatspaceandlight.com (replacing the [a] with an @ symbol) if you’re considering an MVHR system (or leave a comment below).
How much does designing an MVHR system cost?
First step, you need to get a bespoke design of your MVHR ducting layout. Designing an MVHR system in a 200m2 semi-detached home with perhaps one bathroom, two ensuites and three or four bedrooms will cost approximately £700 +VAT. *EDIT* – prices have levelled to approx. £600 +VAT for a 200m2 property as of December 2020.
Be wary of “free” MVHR designs – they are often rushed and cause issues with the trades on site during the build, eg, by missing structural conflicts. MVHR suppliers often also hide the design costs by using cheaper materials in the supply costs, to increase their profit margin.
It takes two to six weeks to design a good residential MVHR system from scratch, and the designer will need:
- structural and architectural drawings (in pdf) – or even sketches will do;
- guidance on any lowered ceilings or voids;
- electrical layout diagrams (so room valves don’t conflict with lighting layouts).
When should I design my MVHR / HRV system?
MVHR duct design should be done early enough in your build programme that the ducting can be installed before first fix plumbing and electrical services.
This is because every extra bend or turn in your MVHR ducting layout will increase air disturbance, which could lead to a noisier system. Hence, diverting wiring or plumbing is a much better idea than diverting ducting. Good MVHR designers like ourselves will minimise the number of duct bends, but that’s no good if you get on site and the plumber has already blocked off all of your service runs.
Luckily, we can design MVHR systems very quickly, so don’t worry if you’re anxious that you’ve left it too late. Contact us now and we can help.
How much do the materials cost for an MVHR system?
A top quality MVHR unit from Brink or Zehnder (the high end models that can offer 300 cubic metres to 600 cubic metres of airflow per hour) will cost approx. £3,000 +VAT. *EDIT* – prices for the top-range Zehnder Q200, Q350, Q450 and Q600 MVHR units have levelled to between £1,000 – £2,300 +VAT as of September 2020.
An MVHR unit should include as standard:
- a touch panel (either in-built or as a separate control), so you can programme and commission the unit;
- frost protection, so cold wintry air doesn’t damage the unit
- automated summer bypass capabilities, so that when it’s hot outside the heat recovery element turns itself off.
- EC motors
- G4 or F7 filters
If you want more from your unit there are lots of additional extras:
- Comfort cooling, a small addition to the MVHR unit with a cooling feature on the supply air ducting for hot days. Adding cooling to an MVHR costs around £2,900 +VAT. *EDIT* – the ComfoCool unit is now available for £2,302 +VAT as of May 2020. Please also consider £1,500 – £2,500 ex VAT for wrapping the supply ducts in insulation.
- an enthalpy exchanger, which helps to maintain moisture levels in the home in winter when the air is dry *EDIT* – the enthalpy exchanger is now only an additional £190 +VAT with the standard Zehnder Q unit as of May 2020.
- Plus much, much more – please contact me if you have any questions.
How much does the MVHR ducting and all ancillaries (valves, manifolds, sound attenuators) cost?
In November 2020, ducting and all materials for a 100-150m2 home will cost approx. £2,600 +VAT.
For a 200 – 300m2 home, ducting and all materials will cost approx. £3,200 +VAT.
For homes larger than 350m2, ducting and all materials will cost approx. £4,400 ex VAT.
There are a number of variables to consider that will affect the price:
- The layout of the home – how tricky is it to run ducting?
- Will steel or semi-rigid HDPE ducting be used?
- Is the ducting going into tight ceiling voids? Proprietary plastic oval rigid ducting for smaller voids carries a price premium
- Will your system be designed as a radial system or a branch system? Ie, will each valve run come from the MVHR unit through a manifold, or will you have a single main duct run for each supply or extract length, with each room branching off? Radial systems save money on sound attenuators because you don’t need them, but you need more ducting, so it evens out all in all.
- Sound attenuators to prevent cross-talk will be needed for each room and these are expensive – lots of rooms means extra costs.
Be wary of MVHR suppliers who fail to include sound drum attenuators in their quotations – drum attenuators are vital to dealing with noise, but they are expensive, so less scrupulous MVHR suppliers may “forget” to add them in the cost so that their materials quote seems cheaper – but they will be missed once the MVHR is running. If the supplier is also offering a cheaper unit it means the sound risk is seriously elevated – so additional sound attenuation is a must.
You also need to consider closed-cell insulation, room valves (plastic or steel? Fancy or plain?), condensate traps, strapping, plenums, manifolds, o-rings, spiral steel ducting, screws and boost controls (and any associated wiring costs – unless it’s a Wifi version).
How much does it cost to install an MVHR system in the UK?
A radial ductwork system is exceptionally straightforward to install – particularly if you have our help and guidance using our easy-to-follow design documents and advice. Most of the ducting works can be done with basic tools, with only the steel ducting to be cut with an angle grinder and drill.
For the client or their builder, a radial MVHR system can save a lot of money on install costs – and the performance is superb.
Professional MVHR installers will normally request that all of the ceilings are open and that building works (creating inlet/outlet holes for ducting) is already completed – by your contractor usually. Installing an MVHR system will take a few capable installers about three to five days. First fix is done ahead of first fix plumbing and electrics, with everything set in place up to the valves. Second fix can be done post-decoration, and commissioning will follow.
Installing an MVHR or HRV system via a professional team will cost around £1,500 – £3,500 +VAT as of September 2020 depending on the size of the home (100m2 – 400m2).
Be wary of unknown installers, as quality can vary significantly even amongst the “professional” HVAC installers. We can recommend MVHR installers that we know are competent and fairly-priced – feel free to ask at Patrick [@] heatspaceandlight.com.
Every MVHR design we produce we also commission, balance and hand over, plus we perform a QA check post-installation to make sure it’s been installed correctly.
How much is it to balance and commission an MVHR system?
Commissioning is a crucial aspect of installing an MVHR system. You’ve spent all that money installing it, and now you need to make sure the airflow is balanced to each room to run quietly and efficiently.
Beware those MVHR suppliers who either don’t offer commissioning, or don’t convey its importance – the fine tuning at the commissioning stage is vital to ensure the MVHR system works properly – and it’s not easy to do without calibrated equipment for measuring airflow.
Your MVHR designer will have assigned airflow rates to each individual room in your property at a set rate based on a number of factors, the most important of which will be ensuring the property meets Building Regs and Passive House standards for healthy airflow. For example, kitchens need to extract a minimum of 46 cubic metres of airflow per hour in “boost” mode to deal with the smells, heat and moisture that’s created from cooking and socialising.
Commissioning and reporting on the MVHR system will take a competent technician a full day using a calibrated balometer. If they find significant leaks or they need to come back for any reason (because the unit isn’t functioning, for example), you’ll be billed again for the return.
Commissioning also produces the Ventilation Certificate for Building Control compliance.
Commissioning an MVHR system costs approx. £800 +VAT. *EDIT* – price for commissioning is now nearer £550 +VAT for the average 200m2 home as of November 2020.
So how much does an MVHR system cost altogether?
For a 250m2 (2,500 sq ft) home in the UK with a top-of-the-range MVHR unit and ducting, designed, installed and commissioned properly, will cost:
- £600 +VAT for MVHR design
- £1,952 +VAT for the MVHR unit
- £3,200 +VAT for the ducting and all materials (valves, manifolds, plenums, sound attenuator drums, insulation, etc)
- £550 +VAT to commission the MVHR system
Which gives you a grand total of £6,302 +VAT for a full turn-key design and commissioning service. Installation can be done as a self-install, DIY or installed by a contractor team for approximately £2,100 + VAT (price will vary by region).
A properly designed and commissioned MVHR will guarantee healthy, fresh, filtered air throughout your home, working silently in the background, for 25+ year. The best MVHR systems come with a six year warranty.
If you’d like any help, guidance or pricing for your MVHR system, please contact me at patrick [@] heatspaceandlight.com.
Finally, how much does an MVHR system cost to run annually?
If you have a very airtight home (less than 3 air-changes per hour, ACH), then you should save money on your heating bills with an MVHR system, as it recovers heat and flows it back into the property. It costs approx.£20 – £55 per year in electricity to run a large MVHR system constantly, but you might save a lot more than that on heating bills because it is recovering the heat that would normally be lost to leaks and draughts in the building fabric.
The payback rate for an MVHR system (aside from all of the comfort and health benefits of having fresh, filtered air at an even temperature all year round) could be 15 years or less – that’s better than solar panels, but all buildings will vary.