Need to know
Don’t let airtightness compromise healthy living
Most people think of poor air quality as just being dirty pollution outside and will overlook all that occurs behind their own front door. With self builders insulating and sealing up their houses more to save energy, environment and money, many don’t realise that conditions inside can lead to the air becoming even more contaminated than outside near a busy road.
To live comfortably, people need about 30m³ of fresh air per hour. This means two adults sleeping together have less than an hour before CO2 and water vapour start to build up to the point where condensation and mould spores form. When you wake up tired and your brain’s not in gear (despite having a long enough sleep) it could be because you haven’t been breathing enough clean air during the night.
Certain items in your dwelling emit a cocktail of chemicals called VOCS (volatile organic compounds). These leach out of soft furnishings, chipboard, laminates, plastics, paint, room sprays and detergents. If you’re renovating your home and don’t relay floors with a vapour membrane, radon gas could also be a danger. It invisibly seeps out of the soil where it gets trapped inside your home and is the second biggest cause of lung cancer in the UK. Not to mention the pollutants caused by cooking – especially particulates emitted from gas hobs.
Ventilating your home by poking holes through the skin with archaic technology – unfiltered trickle-vents in window frames (that people then shut up because they’re too draughty) and noisy extractor fans in kitchens and bathrooms (which are never cleaned, so get blocked up) – is not adequate. In fact, to meet the air changes per hour set by Building Regs, you’d need to open all the windows in your house for 10 minutes, every couple of hours. Pretty inconvenient. Plus, if you happen to live in a busy town, do you really want the noise and pollution inside? Besides, you’re just throwing away vital heat – half your heating bill goes to mitigating the effects of ventilation.
Self builders, quite rightly, want to understand how to maintain good indoor air quality, without losing precious warmth. This is where heat recovery ventilation comes into play. It continuously extracts stale air out of wet rooms, whilst drawing fresh air from outside. Up to 95% of the heat is taken from the old stuff and transferred into the new air being put into the habitable rooms of your home via ductwork and ceiling terminals. This can deliver great savings on your heating bills.
If you specify excellent insulation and airtightness in your home, you could go a step further with heat pump ventilation. This has an integral micro heat pump for extra space heating and cooling, meaning you might not need a traditional heating system at all. At Total Home Environment, we speak to self builders who want a healthy, airtight home like this on a regular basis and can advise you on whether this would be a feasible option for your home. Ultimately, with heat recovery ventilation in your home, you can breathe your 10,000 litres of air a day, safe in the knowledge that it’s fresh, filtered and sustainable.