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Showing posts from August, 2022

The ASHRAE Ventilation Recommendations Are Too Low

With winter on its way, I've been thinking a lot about heating and insulation -- specifically, about what the minimum level of power required is given the need to heat up outside air in a properly ventilated home. This led me to the American Society of Heating, Refrigerating and Air-Conditioning Engineers, who provide guidance as to what the outside airflow rate should be to ensure acceptable air quality. Unfortunately, having done the maths regarding CO2 production, their recommendations are far too low. Healthy individuals take 12-20 breaths per minute. Each breath exhales 0.5 litres of air , so each person will exhale 6-10 litres every minute, which at a CO2 level of 4%, contains 100 times the CO2 of ambient air. In order to dilute this to a doubling of CO2 over ambient, around 800ppm, 600-1000 L (10-17 L/s) of outside air would be required, assuming the inhabitants are not engaged in physical activity that would raise their CO2 production significantly. The recommendations f

Local Government Needs Reshuffling, Not Reorganising

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It is generally understood that two tier local government, of a county council with district councils beneath it, is on its way out. The division of responsibilities makes little sense and causes great confusion, especially since many of them need to work together -- waste collection, for example, is a district responsibility, whilst managing the waste collected is a county responsibility. The proposed solution is almost always to replace two tier governance with single tier unitaries. The trouble with unitaries, however, is size. A unitary has responsibility for things like parks, which function best under smaller authorities, but also has responsibility for highways, which are best served by a large authority. Instead of unitaries, consideration should be given to reshuffling responsibilities. Consider this list of what councils do (from NewLocal.org) :   Elections are handled at the district level, and yet responsibility for registering births and deaths and marriages is a county af