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Effect of Air return on heat efficiency
Have a Richardson system with 2 loops: one has 137 sf of attached radiation, the other 221 sf. Booth are vented by 1" dry air returns by same vent above boiler. The loop with 221 sf heats less efficiently than other but it's no major problem. Richardson literature stresses need for each loop to have own vent, also, where more than 200 sf is attached the dry pipe should be 11/4" from radiator that puts sf over 200sf. Would changing pipe be wise? Talking about a 16' run to drip. Adding a vent to this line entails cutting-off and dropping a new drip as both loops shared same dry drip. In the past I've removed vent to see if it made a diffenence, it did not.