What we do
Domestic and commercial work across South East London — with the airflow measured at the grille, not assumed from the box.
Heat recovery care plans
Ventilation is the one thing in a house that stops working without ever breaking. A care plan is a booked visit every year: filters, a full clean, and every valve measured with the figure written down next to last year’s — so you know it is still doing the job it was put in to do.
Domestic and commercial ventilation, heating and cooling — designed properly, installed neatly, and commissioned so the airflow is measured rather than assumed.
Whole-house mechanical ventilation with heat recovery — designed, ducted and balanced so every room gets its share without throwing your heating out of the window.
Rigid and spiral ductwork, sized and routed to keep resistance and noise down. Set out square and bracketed properly — because on an exposed run the setting-out is the finish.
Air handling units and fan coil units set, connected and commissioned — plinths, anti-vibration mounts, flexible connections and access left where the next person can actually reach it.
Bathroom, kitchen and utility extract that meets the Part F rate at the grille, not just on the box. Ducted to outside properly, never into a loft void.
One unit in the loft — or on the wall of a flat with no loft — pushing filtered air gently into the whole house. The least disruptive whole-house answer to condensation.
Installation and planned maintenance for split and multi-split systems — filters, coils, condensate and performance checked before the hot weather finds the fault for you.
A system nobody services stops doing what it was installed to do, quietly. A booked visit every year, every valve measured, and the figure written next to last year’s — from £199 a year.
Measurement first: humidity, surface temperatures and actual extract rates. You get a written report on what is causing it, not a guess and a quote for a bigger fan.
Supply and extract for units, venues and workspaces — coordinated with the other trades so the ductwork lands where the ceiling design says it should.
Investigation, a written report naming the cause, the fix, and a dated evidence trail — because under the Homes (Fitness for Human Habitation) Act the question is not only whether you fixed it, but whether you can show what you did and when.
Heat recovery
An MVHR unit extracts damp air from your wet rooms and supplies filtered fresh air to the bedrooms and living space, passing the two streams either side of a heat exchanger so most of the warmth stays in the house.
It only works if the ducting is right. Insulated where it runs cold, kept as short and straight as the building allows, and balanced room by room at commissioning — otherwise you have an expensive box moving the wrong amount of air.
See how it works in your homeHeat recovery, in section
An extract fan throws your heating out through the wall. A heat recovery unit takes the warmth out of the stale air on its way past and hands it to the fresh air coming in. Scroll to follow one lungful of air all the way through the machine.
Illustrative figures for a good counterflow unit — about 90% heat recovery — on a 3 °C day. Manufacturers quote up to roughly 90% for this type; the real numbers depend on the unit and the duct layout, and are proved by measurement at commissioning, not by the brochure. The efficiency also depends on the filters being changed: a loaded set drops the airflow and takes the recovery down with it.
Extract · 21 °C
A valve in the bathroom ceiling pulls air out continuously — from the rooms where the moisture is actually made. It leaves at room temperature, taking the moisture with it before it reaches a cold wall and turns into condensation.
Exhaust · 5 °C
Through a filter, through one half of the exchanger, through the fan and out to the wall grille. By the time it reaches the outside it is close to outdoor temperature — the warmth you paid for has been left behind in the unit.
Intake · 3 °C
Filtered outdoor air enters through its own grille, set well away from the exhaust so the unit can't breathe back in what it has just thrown out, and runs into the other half of the exchanger. The plates keep the two streams apart: heat passes between them, air never does.
Supply · 19 °C
The warmed fresh air is delivered to the bedrooms and living room. That is the whole trick: the full air change the regulations ask for, without paying to heat the house twice — which is exactly what an extract fan on its own makes you do.
Ventilation is the only thing in a house that quietly stops working without ever breaking. Nothing trips, nothing leaks, nothing makes a noise — the filters load up, the airflow halves, and the first anyone knows is a black line round the bathroom ceiling two winters later.
So we do not sell a callout. We sell a visit that ends in a measured figure, the same way the installation did.
Filters to the manufacturer’s interval, heat exchanger drawn and cleaned, condensate trap checked, and the unit re-balanced — then every valve re-measured and the figures written down.
A loaded filter set can take a third off the airflow before anyone notices. Re-measuring is the only way to know it is still doing what it was commissioned to do.
Performance tested at the grille with a calibrated anemometer against the Approved Document F rate for that room, cleaned, and re-commissioned. If it cannot make the figure, you get told why.
Most of the fans we test in older properties do not hit their rate. A test is what turns “there is a fan in there” into something you can act on.
Filter changed, airflow checked at the diffuser, heater and controls tested, and the loft conditions round the unit looked at while we are up there.
A PIV pushing through a blocked filter is a fan heating a loft. They are cheap to service and almost never are.
Filters, coils, condensate and drainage, electrical connections and a performance check before the hot weather finds the fault for you.
Refrigerant circuit work — recovery, charging and leak testing — is carried out under F-Gas certification by our refrigerant partner, because it is illegal to do otherwise. The work listed above needs no F-Gas certificate and we do it ourselves.
One visit per property per year, planned round the summer rather than squeezed into the winter when everything else is going wrong. Each one ends with a dated certificate carrying the measured figures, filed against that property in your account.
That is the record that answers a complaint before it becomes a claim: not “it was serviced”, but what it was achieving, on what date, against what standard.
Ask about a service planYou do not need the ventilation lecture. You need the ductwork in between the joists before the boards go on, on the day you said, and the numbers for building control at the end of it.
First fix
Ventilation is won or lost before the ceiling goes on. Once plasterboard is up, the duct route is fixed, and a run forced around a joist it was never planned for will cost you airflow for the life of the building.
We set out first fix against the drawings and the other trades — joist positions, service voids, where the pipework and cabling are already going — so the ducting takes the shortest sensible route rather than the last gap left over.
Talk to us before first fix
Send us a message with what you have noticed at home. We will tell you honestly whether you need a survey, a system, or neither.
Or see what it costs — unlike most in this trade, we publish our prices.
Trained on the systems we install
Most trade sites show you a row of logos. These are the actual certificates, held by this business. Tap either one to read it, or download the PDF.
