Whereas it is changing into extra frequent for an MVHR (mechanical air flow and warmth restoration) system to be included in a brand new, self construct mission, the choice to retrofit MVHR is much less well-liked.
However, with an rising give attention to the necessity for our properties to be hermetic and power environment friendly, together with an MVHR arrange in your house renovation plans should not be dismissed.
Whereas it is not as straightforward as in a brand new construct, it’s possible and may nonetheless reap rewards. Discover out what’s concerned, how one can get it proper, and when it’s best to think about different choices as an alternative.
Potential points with an MVHR retrofit
“Retrofitting MVHR into an present dwelling will be technically difficult, however it’s definitely achievable with the proper planning and experience,” says Russell Smith, managing director and co-founder of Ecofurb.
“In older or occupied properties, house constraints, structural limitations, and the necessity for minimal disruption can complicate the method,” he explains.
“Present properties with stable timber joists, new metal beams and a few vaulted ceiling could make discovering the routes for the MVHR ducts very difficult,” confirms David Hill, managing director of Carbon Legacy Ltd.
Nevertheless, there are a variety of various components that may influence how straightforward the job of putting in MVHR is.
“It largely is determined by the property’s format, present air flow techniques, and the extent of airtightness. Properties present process vital renovation or entire home retrofits supply the very best alternative for MVHR integration, as ductwork will be hid inside flooring, ceilings, or partitions extra simply,” explains Russell.
“However, with tailor-made design, cautious coordination, and expert set up, MVHR will be efficiently applied, delivering improved indoor air high quality and power effectivity,” he confirms.
Russell Smith is the founder and Managing Director of Ecofurb, a service devoted to offering neutral, personalised recommendation on dwelling power effectivity retrofits.
David Hill has over 40 years of expertise in each the private and non-private sectors, and has performed a pivotal position within the growth of over 5000 properties. His latest tasks embody 1100 low-energy models reaching 40-100% carbon reductions in comparison with 2002 Constructing Regulation requirements. In 2009, he based Carbon Legacy to push the envelope in zero-carbon housing options, marking vital milestones with the event of the primary zero-carbon Code 6 properties in Upton, Northamptonshire, and main the primary zero-carbon refurbishments in East Leake, Nottinghamshire.
The way to make a retrofit simpler
Whereas putting in MVHR in a brand new construct means it may be fitted on the proper time, with out going through stable partitions, present ceilings or restricted house, to retrofit MVHR requires extra work upfront say the consultants.
“There are a number of measures that may make MVHR set up in present properties simpler and simpler,” confirms Russell Smith. “Early stage planning is at all times essential as contemplating MVHR on the outset of any retrofit or dwelling renovation mission permits for higher integration of duct routes and unit placement.”
“The extra intensive the renovation then the extra possible you’re of discovering options to duct routes,” provides David Hill. “It is also, price noting, bungalows with present lofts are excellent as all of the duct work and the unit can go within the loft.”
“Be ready to have quite a few discussions each earlier than and through set up with the shopper, architect, engineer and different trades as properly,” says David. “Plus, putting in ducts as early as potential within the renovation, and accepting that extra ceilings or flooring could have to return as much as accommodate ducts and vents, will all ease the method.
“Additionally be sure to ask your installers to be as clear and sincere as potential, and ensure they speak you thru every stage of an set up, agree each duct route and compromise you will have to make to get the ducts and ceiling vents the place they should go,” he provides.
“Partaking skilled designers and installers who perceive the precise challenges of retrofit tasks is essential to making sure a clean and profitable set up,” agrees Russell.
In addition to creating service voids from present areas, there are additionally a lot of completely different strategies the consultants make use of when enterprise a retrofit MVHR scheme that may assist disguise the set up and keep away from utilizing up beneficial house.
“Utilizing compact or decentralised MVHR models in properties with restricted house also can simplify set up, says Russell, “and moreover, bettering the house’s airtightness earlier than or in the course of the retrofit ensures the MVHR system operates effectively.
“One frequent method is to create service voids behind fitted furnishings reminiscent of wardrobes, kitchen models, or toilet cabinetry, permitting ductwork to be hidden with out main structural work,” he suggests.
“Boxing in ducts alongside the tops of partitions or working them by way of present bulkheads or chimney voids is one other efficient technique. Versatile or semi inflexible ducting may also be utilized in tight areas the place inflexible ducts wouldn’t match simply,” he provides.
“In essence, good design and a little bit of creativity can go a good distance in making MVHR retrofits each sensible and unobtrusive,” says Russell.
MVHR retrofit prices
The prices for an MVHR system in a new-build can differ relying on how subtle you need your system to me. Properties with MVHR that’s according to Passivhaus air flow requirements will naturally discover themselves paying greater than householders who go for one thing extra economical.
However, in relation to an MVHR retrofit, it is more likely to be costlier once more.
“Prices will depend upon the complexity of the system and the dimensions of the home and differ between £8k and £20k for big homes with 2 models,” says David Hill.
“Elevated prices are primarily as a result of further labour and design complexities concerned in adapting the system to an present construction,” explains Russell Smith. “Prices usually embody not simply the MVHR unit and ducting, but additionally the time required to plan routes, make structural changes, and perform a cautious, usually bespoke set up.
“That mentioned, the expense will be offset when MVHR is included right into a broader entire home retrofit, notably one that features enhancements to airtightness and insulation,” he says.
Is my dwelling appropriate to retrofit MVHR?
Though every dwelling will must be assessed on a person foundation, Russell Smith and David Hill share some examples of properties which have efficiently been retrofitted with MVHR.
Mid-terrace Victorian property upgraded with MVHR
“One notable instance or a mission is a mid terrace Victorian property present process a deep retrofit to enhance power efficiency and luxury,” says Russell. “The home offered typical challenges – stable partitions, restricted service voids, and the necessity to protect the constructing’s character.
“We took an entire home method, bettering airtightness and insulation ranges first, which made the MVHR system viable and simpler. Ducting was rigorously routed by way of the loft and dropped down by way of inbuilt wardrobes and boxing in corners of rooms.
“We coordinated carefully with joiners and builders to create hidden routes behind new fitted furnishings and ceiling voids. The outcome was a discreet, environment friendly system that supplied glorious air flow and warmth restoration with out compromising the house’s aesthetics. It was a posh job, nevertheless it demonstrated how considerate planning and collaboration could make MVHR retrofits successful.”
Sustainable design ideas required entire home renovation
David Hill shares a latest scheme the place the householders have been eager to do all they might to create their future dream dwelling when it comes to sustainable design primarily based on confirmed applied sciences.
“In addition to putting in a floor supply warmth pump for house heating and sizzling water, photo voltaic panels and a Tesla Powerwall 2 to generate free electrical energy, the homeowners wished to retrofit MVHR to offer a wholesome dwelling and scale back working prices,” explains David.
To make the retrofit potential and efficient, a lot of completely different strategies have been employed,” says David, together with:
- small areas of dropped ceilings
- hiding vertical ducts at the back of built-in wardrobes
- rising the dimensions of soil & vent boxing to hide ducts
- oversizing of timber studs to once more cover vertical ducts
- accepting longer duct runs than regular to work with present ground joist runs
- getting the engineer to just accept some holes in metal beams in tough places
When a retrofit MVHR may not be possible
Whereas MVHR will be retrofitted into many forms of properties, there are particular conditions the place it might not be probably the most appropriate answer.
“Properties which are notably leaky or poorly insulated, reminiscent of older properties with out substantial cloth upgrades, could not profit totally from MVHR, because the system depends on a great degree of airtightness to work effectively,” warns Russell Smith.
“In these circumstances, pure air flow and extract solely air flow may be extra applicable till the constructing cloth is improved. Equally, properties with very restricted house for ducting, reminiscent of some flats or listed buildings with strict conservation necessities, can pose vital sensible and regulatory challenges.
“Nevertheless, even in these eventualities, decentralised MVHR or hybrid techniques could supply a workable various. Finally, it’s not a lot that MVHR needs to be averted completely, however that its feasibility is determined by the house’s situation, constraints, and the scope of the retrofit,” says Russell.
FAQs
Are there options to a retrofit MVHR system?
“Sure, there are various measures that may assist obtain comparable outcomes to MVHR, notably in properties the place full system set up isn’t sensible,” says Russell.
“One possibility is to enhance pure air flow by including trickle vents and utilizing strategically positioned core vents to encourage cross air flow. For extra managed options, demand managed extract air flow (DMEV) or steady mechanical extract techniques will help take away stale, moist air from kitchens and loos whereas sustaining cheap air high quality.
“These techniques are sometimes easier to put in and fewer invasive than MVHR. Pairing them with airtightness enhancements and excessive efficiency home windows can considerably improve indoor air high quality and scale back warmth loss,” he says.
“Whereas these options don’t supply the identical warmth restoration advantages as MVHR, they’ll nonetheless contribute to a more healthy, extra power environment friendly dwelling when used as a part of an built-in retrofit technique.”
“If you weren’t finishing up main renovation works however nonetheless wish to enhance your air high quality to scale back mould, humidity and co2 ranges then entire room and even two room by way of the wall options are an possibility,” provides David Hill
“They are usually cheaper to put in than entire home MVHR however the draw back can be that it’s not a completely filtered system and it doesn’t have the facility of MVHR to extract from bigger rooms.”
Is a retrofit MVHR well worth the disruption?
“Whereas the upfront funding could seem excessive, the long run advantages, reminiscent of improved indoor air high quality, lowered heating demand, and safety of constructing cloth, could make it a value efficient part of a complete power effectivity improve,” says Russell Smith.
“In order for you humidity stored at under 50%, CO2 ranges under 500 ppm, pollen and allergens stored to a minimal, and a system that’s barely noticeable in use, highly effective sufficient for an entire home and adapts to deal with situations, then MVHR is totally the way in which to go,” agrees David Hill.
Nonetheless seeking to perceive why you would possibly go to the expense and disruption of retrofitting MVHR? Learn the way putting in MVHR fully stopped condensation in Homebuilding & Renovation’s power professional David Hilton’s dwelling, and whereas there aren’t many, additionally be sure to are totally conscious of the few disadvantages of MVHR.
