Building a house

Question

Dear ladies and gentlemen,
we have a 3-year-old son with CF. We are planning to start building a house in the course of the next year.
There is the possibility, to equip the house with a controlled living-room ventilation with regaining of heat. Hereby, used air is permanently sucked out of the appartment and its heat is transmitted to the fresh air via a heat exchanger, which is passed into the the rooms then. By this the needed exchange of air is provided without manuel opening of the windows and the performance of mould is inhibited.
I see this to be a great advantage, I am not sure however, if probably because of the occurance of humidity in the pipe system the whole can turn into a disadvantage. Can you tell me your opinion about this?

Answer

Hello,
first of all I would like to apologize for the late answer. Now to your question: indeed the danger of "contamination" with bacteria or mould fungi is well known from all possible air-improving devices / ventilation devices. However that is always a problem of insufficient servicing, at least this can be said for air-conditioning devices. Especially problematic it gets at a very high occurance of dust like for example at the production of paper, where organic material like cellulose in the dust overweighs, which is together with water a very good agar for mould fungi. But one has not let it come to that. Such a regaining of heat has been developed for reasons of the protection of the climate, in order not to lose heating energy via airing. If this is however indeed an advantage for the health, I cannot say, because on this I did not found any investigations. There it is reduced all the time on the "harmlessness" as long as it is serviced well and right. But an otherwise dry (close) house, that can be aired effectively (no trapped, inside lying bathrooms, were the humid-warm air stays for a long time etc), does not have any critical health risks.
My conclusion, that however can not in any respect be supported scientifically: from the health point of view a well aired, dry house is optimal, concerning a well serviced air-conditioning device/regaining of heat there are not objections against.
Yours sincerely,
Prof. Dr. TOF Wagner

09.11.2010