Ready-made home ventilation systems are very expensive, but a home-made supply is very inexpensive.
I bought a Ukrainian fan Vents TT 125 and studied how it behaves with a significant slowdown.
My homemade home ventilation (https://ammo1.livejournal.com/1023738.html) has been working for the third year. I decided that I needed to make an inflow in the country.
The main requirement for a fan for a domestic supply is that it must be quiet, while providing the necessary air flow (at least 30 m³ per hour for each person in the room).
Domestic fans are not suitable - they are too noisy, and when they slow down, they give too little flow.
The simplest and cheapest option is to use industrial duct fans with a high flow rate, slowing them down to almost complete noiselessness. Most fans slow down well only by reducing the voltage, so a LATR is needed or a homemade transformer (electronic seven-story regulators are not suitable - the fan will start strongly buzz).
I bought a fan for trial Vents TT 125
. I bought it at Leroy Merlin for 2942 rubles (there it can be returned without any problems, if that).This fan has two speeds (power is connected to one of the two contacts), at the first speed the air flow rate is 220 m³ per hour and the noise level is 28 dBa at distance of 3 m.If it seems to someone that it is quiet, I will disappoint you - it makes a very noticeable noise and not only will sleep with it, but it will not be possible to be in the same room comfortable.
As the voltage drops, the fan becomes much quieter. At 165 V it is very quiet, at 130 V and below it is almost silent.
I built a temporary structure out of a cardboard box to measure the flow rates with a filter (used a cabin filter for Nissan Murano and Teana, size 270x277 mm).
First I measured the performance without a filter. The impeller of the anemometer is fixed at a distance of 5 cm from the outlet of the fan pipe.
Second dimension with filter.
Here are the results. M / s to m³ / hour translated using an online calculator http://helpeng.ru/ov/vent_flow_air.
Consumption at a voltage of 230 V without a filter turned out to be 16% more than the passport one. I don’t know if the fan was made "with a margin" or my measurements are not accurate.
In general, the results were encouraging. At a voltage of 130 volts and almost complete noiselessness, the fan gives 66 cubic meters per hour with the filter, which should be enough for two people so that the CO2 level in the room does not rise above 900 ppm.
Soon I will install a fan in the country and I will be able to get practical results. Let's see if they coincide with the theoretical ones.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, in LJ, Zen, Mirtesen, Telegram.
My projects:
Lamptest.ru. I test LED lamps and help figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in Telegram @ ammo1 and by mail [email protected].