Anyone who has already acquired a carbon dioxide (CO2) level meter knows how important it is to continuously supply fresh air to the living space. The simplest solution to this problem is to always keep the window open, but for me, as in many other city houses, it is not comfortable because of the street noise, and it can be very cold with the window open.
The second solution to the problem of fresh air - forced ventilation, air supply from the street. I tried to use Tion, iFresh, Ballu compact ventilation systems, but I realized that they all do not suit me - with sufficient air flow they make too much noise. Apparently, it is impossible to make a quiet system with a fan in the room.
That is why I made the home ventilation system myself.
Installation is located on the balcony. The air is taken from the street, filtered, and through the air duct fixed on the outer wall of the house, is fed into the next room.
In the plywood box, which cost me about 300 rubles, is a fan Lissant VK125B for 2,400 rubles and a car cabin filter for 240 rubles.
When powered from the mains, the fan gives a huge air flow (320 m3 / h) and makes a lot of noise, so I use it at low revs. Unfortunately, when using electronic power regulators, the fan starts to buzz loudly, so for now I’ll just smoothly change the voltage on the fan using LATR for 1,150 rubles.
At a voltage of 110 volts, the fan delivers a flow of 60 m3 / h and consumes about 25 watts. This expense is enough for two people.
Air is supplied to the room through a 125-mm hole from the KIV-125 valve, which was properly installed during the construction of the P44T series house. To reduce the noise (both from the fan and street noise), a sound suppressor from the KIV-125 valve is installed in the hole.
The operation of the ventilation system is of course audible, but its noise is much less than that of compact ventilators at the same flow rate. When I'm alone in the room, the voltage can be reduced to 90 volts and the system noise is almost inaudible.
For two weeks of use, the white filter turned gray. It probably makes sense to change the filters once a month.
In the coming days, a CO2 meter with three-step fan control for $ 44 will come to me from China. I want to replace the LATR with either three high-voltage film capacitors, or buy a small 40-watt toroidal transformer 220/220 and retract from the secondary winding, unwind it and wind it back. The result is an automatic system that controls the three ventilation speeds.
In the cold season, the outside air must be heated so that it is not cold in the room. At first, I wanted to install on the wall in front of the hole from which the air was blowing, an ordinary cheap fan heater with a ceramic heater, throwing a fan out of it, but then I had the idea to direct the air flow to the radiator. It is possible that this will be enough. Tomorrow I will fly to Japan, and when I return I will experiment.
The self-made air handling unit cost me less than 3,000 rubles (not counting the price of the Lattice), I have been working for two weeks and I am pleased with the low noise level and fresh air in the bedroom (the CO2 level does not exceed 700 ppm).
© 2017, Alexey Nadyozhin