What pipes to choose for ventilation in a log house?

Good afternoon, Olga.

Ventilation calculations are based on the cubic capacity of the room. You did not indicate the height of the ceilings and whether the attic is a year-round living space.

The air flow rate also affects the air exchange rate. In a private house, the natural speed in the ventilation duct rarely exceeds 2 m3 / hour, 1 m3 / hour is taken as the standard. Based on these data, a pipe with a diameter of 125 mm. able to provide a maximum air exchange of 44.2 m3 / h. In turn, the ventilation pipe is 160 mm. able to provide a maximum air exchange of 72.3 m3 / h. Total, the total air exchange under ideal conditions will be 116.5 m3 / h.

SNiP 41-01-2003 states that 30 m3 / hour should be replaced per person. You live with your husband, this is 60 m3 / hour. Under ideal conditions, a flow rate of 1 m3 / h occurs 116.5 m3 / h. Naturally, with a decrease in speed, the volume of replaced air will fall.

Children come to the weekend, as I understand, more than one person. This is added at least 60 m3 / hour. That is, at the weekend it is necessary to replace 120 m3 / hour of air with clean air.

For convenience, you can see table 1. The throughput for all pipe diameters at different air flow rates is clearly shown. In the table there are two standard sizes of ventilation galvanized pipes and wall thickness depending on the diameter.

The specialist suggested in my opinion the ideal option for your particular case. Miscalculations are made by me superficially. The reason is indicated at the beginning of the answer.

I advise you to additionally familiarize yourself with this article on our website.