What is recovery

AIRMEN ADVISE …

What is good ventilation with recuperation?

First, let's explain what recuperation actually means in the air engineering world:

The term recovery used in building ventilation systems is synonymous with heat recovery. That is that during ventilation you use the energy of the air (which you let out when you ventilate the windows) to preheat the fresh outdoor air that you bring into the house.

Thanks to the so-called efficiency of recuperation, the fresh outside air that you let into your home does not have an outside temperature (e.g. -5°C), but an acceptable, e.g. 16°C or 18°C (at an interior temperature of around 20°C). The recuperator can simply be imagined as an exchanger (plastic or aluminum), through which supply and exhaust air flow in opposite directions and each in its own way, so that they do not meet. They transfer heat to each other thanks to the heat exchange surface that is between these air streams.

You can read more about the recuperator and its effectiveness in our article here .

There is a general opinion that ventilation with recuperation is firmly connected with some kind of savings and that it is a technology only for passive houses. Another myth is that homeowners who are equipped with heat recovery ventilation cannot open their windows and that I am living in some kind of artificial greenhouse.

In our opinion, the biggest advantages in an air recovery system are:

1) Sufficient fresh air throughout the year and quick removal of odors
In order to have enough fresh air at home, we don't have to open the window every 2 hours. In recuperation systems, the ventilation unit takes care of this. All odors disappear within a few minutes.

2) Reduction of moisture in problem buildings
The whole system, especially in winter, significantly reduces air humidity, as well as condensation on the walls and thus mould. Since no part of the walls is significantly cooled as with an open window, there is no problem with this type of condensation either.

3) Clean air for allergy sufferers and in places with flying dust
How to have fresh air at home when there is pollen or flying dust outside (Ostrava and other big cities)? As the units are equipped with quality filters, you are in control of what you breathe and it is up to you what you take home.
(article on filtering here )

4) Energy/heat saving
If you haven't ventilated regularly (i.e. you haven't opened the windows at regular intervals) then after installing ventilation with recuperation you probably won't find a lower amount for heating on your next invoice. However, if you regularly ventilate, so that the recuperation unit is ventilated, then the difference in winter would be substantial.

5) Reduction of radon concentration
Ventilation with recovery with slight overpressure is perhaps the only suitable type of ventilation for houses with this problem.

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Myths about recovery:

1) It hums and blows on people's heads.
New, well-designed and executed ventilation systems with recuperation are definitely not noisy. If you don't stand near the unit or stick your head 30 cm to the outlet, you won't even notice that the system is running. This also applies to the perception of air flow.

2) Mold grows in the pipes
A common notion of laymen. Since all the air is filtered and considerably dehumidified, no dirt gets into the supply pipe.

Modern pipe systems are equipped with an antibacterial coating.

Since we clean the systems, we know that there are almost never problems with properly filtered air. The drainage pipe is mostly contaminated with dust, especially at the outlets in the kitchen and bathroom. As long as there is enough flow area for the flowing air, nothing happens. The exhaust air in this pipe is directed away from the house and does not physically meet the supply air.

4) Recuperation is only for passive houses
This is a complete misconception. If you live in any house that is insulated and has new windows, ventilation with recovery is very useful and healthy for both you and your wallet.

5) Ventilation with recuperation is above standard and an unnecessary luxury
The strange thing is that in our lives we care about what we eat, what we wear, what we drive...but we don't care much about what we breathe 24 hours a day. In the basic variants, you can purchase ventilation for an apartment from 60,000 CZK and ventilation for family houses in the range of 75,000 – 120,000 CZK. Annual costs are CZK 3-5,000. And the lifetime of the system is around 30 years.

Last edit: 13/12/2021