VMC in self-construction

[chatelot16]

with the crossed flow the air to be heated which passes over one edge is in contact with the very hot viscous air, but the air to be heated which passes on the other edge only sees the air of the viscous air already cold since it has crossed the exchanger: it is not optimum at all

with the counter current the air to be heated begins by being preheated by the viscous air which has passed through the entire exchanger, then as it advances it heats up and finishes in contact with the viscous air. hotter

the delta t between the 2 faces is constant over the entire length of the exchanger: the efficiency can be as close as you want to 100% if the surface is sufficient

for the against the current I do not see any distinction between crossed or not!

the plates must not be too good conductors of heat so as not to lower the heat from the hot end to the cold end

with flat sheets they risk bending and not keeping a constant spacing

my solution is with corrugated sheet: length of the exchanger = 90cm = width of the normal corrugated sheet: but the effective length is rather 1m since the air must follow the corrugations of the sheet

width of the exchanger from 20 to 50cm depending on the desired power: thanks to the corrugation the spacing between the plates remains constant, even if the plates are only kept on the edges

my house has sufficient draft not to need ventilation: this type of exchanger is mainly used for the recovery of heat from an air-cooled generator

[antoinet111]

Hi, do you have pictures?