> One example? In Canada we have a standard for air tightness, and more, called R-2000. Houses with this standard have to have heat exchangers, for they are so

> One example? In Canada we have a standard for air tightness, and more, called R-2000. Houses with this standard have to have heat exchangers, for they are so airtight, that they require air be circulated in from outside. When it is -40C, this change can mean heating costs of 200/month vs 2000! This *is* what we call a modern and well-designed system.