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Heat Recovery Ventilation- A Breath of Fresh Air!

By Renew iT Energy Solutions | Published: 2nd Jul, 2007 | Viewed 2902 times The Dilemma Most of us are aware that one of the first steps in increasing the thermal efficiency of our home is to insulate, insulate, and then insulate! In this process, many of us are putting increasing emphasis on ‘sealing’ our homes to prevent heat loss. Having done this, we then need to ventilate so we put a hole in our wall or window. Doesn’t make sense, does it? The current building regulations for ventilation, Part F1, stresses that the main functions of a ventilation system on a general level should: ‘provide an adequate supply of fresh air for using an area or building; achieve occasional rapid ventilation for dilution of pollutants and of moisture likely to produce condensation in habitable rooms, kitchens and rooms containing sanitary appliances; and extract moisture from areas such as kitchens and bathrooms, where it is produced in significant quantities’. The majority of homes and buildings in Ireland are fitted with wall or window vents. This allows valuable heat to escape and creates draughty rooms. Between 33-50% of the building’s heat loss will occur through this form of natural ventilation. But we need ventilation to ensure a healthy living space. There is a significant increase in the number of people suffering from asthma and other respiratory problems aggravated by poor air quality. The dust particles, mites and bacteria in the air are not visible to us. Even if you are not a sufferer of a respiratory ailment there are other symptoms of poor air quality such as, drowsiness, aggravated sinus, headache, eye irritation, skin irritation and a general lethargic feeling. Therein lies the dilemma. Buildings are required to retain heat, but circulate air. Is one compatible with the other? The Solution Yes, amazingly heat retention and ventilation are compatible and the solution lies with Heat Recovery Ventilation. Heat Recovery Ventilation (HRV) is not a new technology, but is only now gaining popularity in Ireland. Originally a Scandinavian product, the HRV system is an extremely efficient, health-beneficial, cost effective solution to saving energy. The HRV System will provide a continuous supply of clean, fresh, filtered air while at the same time recovering and re-distributing heat throughout your home. The HRV unit will sit in your attic (typically) and is connected to the outside by 2 lines of ducting- one to supply fresh air and one to expel stale air. The ducting is connected to your rooms by small ceiling valves. The first line of ducting extracts warm, moist, stale air from areas such as kitchens, bathrooms and utility rooms and expels it outside. However, before doing so the HRV unit absorbs the heat of this air in its heat exchanger. The fresh air coming in from outside is filtered, warmed in the heat exchanger to 97% of the heat that went out, and then supplied to rooms such as bedrooms, the study, playrooms etc. As both the supply & extract ducts remain separate at all times, no cross contamination occurs. A good HRV unit will come with a Summer Bypass to ensure your home or building remains cool during hot weather. The Benefits of a Good Heat Recovery Ventilation System: - Enables draft free ventilation - Delivers pure fresh filtered air 24/7 - Helps re-distribute heat throughout house with a high rate of heat recovery (97%) - Has an EU F8 Pollen Filter to reduce allergies caused by dust or stale air (e.g. Asthma) - Uses efficient motor fans such as the brushless EC-DC range to provide very low levels of energy consumption - Silent operation - Eliminates condensation, Prevent mould, and Removes Radon How much will a Heat Recovery Ventilation System cost? HRV systems may not be dirt cheap and there are no grants available, but they will provide you with a lifetime of health and savings benefits. For a new 2,800 sq ft home the average price of a good system will be €5,500 plus VAT. For this you should have your system supplied and fully installed with ducting. It may seem expensive, but you will be reducing heat loss by 33-50%, while providing a healthy living environment. In time the cost of a HRV will not be considered an ‘extra’ but instead will be factored in as a typical cost of a building….roof, windows, walls, HRV etc. Any reader who has lived or is living is a house with wall vents will probably agree that it’s a small price to pay to be able to seal them up! The annual running cost of a good HRV system will be approximately €30-€40. Can a HRV be fitted in an existing home? Yes it can. However, to gain the benefits of the system it is recommended that you seal your home as much as possible beforehand. In a bungalow there is easy access to each room through the attic to install ceiling vales and ducting. In a dormer or two-storey house it is not such a simple process as you need to be able to run the ducting from the attic are to the ground floor ceilings of the house e.g., through built-in wardrobes, hot press etc. Heat Recovery Ventilation is something that should be seriously considered for all new houses as both the energy and health benefits are immense. As the system enables you to fully seal your home, your home Energy Rating is instantly improved. Don’t be put off by the fact that this technology seems ‘new’. It’s not a new technology; it is just relatively new to Ireland. An increasing number of property developers and self-builders are recognising the importance of such a system and in time it will be strange to find a new home being built without one. So, having read this article, if you were looking at two similarly priced houses and one had a HRV system installed and one didn’t, which house do you think you would you buy? Easy, isn’t it! For further product information, and SEI grant forms you can contact Renew iT Energy Solutions on 094 9621921, info@renewit.ie; www.renewit.ie or visit their showroom at Ballindrimley, Castlerea, Co. Roscommon. BACK TO ARTICLES