Considering tackling an off-grid install. Power consumption is a concern. I tried unsuccessfully to convince the client to install the boiler in the basement and do a normal upfeed gravity system which would have been hard enough considering I've never done gravity feed (who has?). Boiler must be outside so a pump is needed and can be used to also supply basement/DHW. My question is: it seems like a waste to have hot water piped to the basement and not take advantage of a gravity feed setup. I'd like to keep it closed/pressurized but am trying to wrap my head around this ancient technology. Could I just use a hydraulic sep and run the upper floors off there? Or will I need an Xchanger to properly separate flows? Has anyone installed a gravity system in the last 100 years? Maybe on an Amish farm?