As I understand it, the compressed air and demand pump systems both maintain around 35 psi... a good question and an important consideration, though... however, for the kinds of hot-water use for which the tankless systems are 'best', i.e. 'unlimited hot water', a city-water supply would clearly be the preferable source. In 'boondocking' situations - where one's water supply is necessarily limited to what one carries with - the traditional small propane fired systems seem more suitable for 'navy showers', since the initial cool water is that which is in the hot-water line between faucet and heater... the tankless systems take a few extra seconds (pints? gallons?) to get the water flowing through it up to temperature.... re: 'venting' natural gas/propane tankless heaters: venting up a lined chimney (which usually requires a vent fan, too) is only necessary if the distance to the vent outlet is greater than 10 - 15 feet, or something on that order. the Takagi (i don't work for them, honest) i installed has a vent run less than five feet to an outside wall of the garage, and only about a foot of vent-height above the heater (an important factor). If i were to use a tankless heater for maximum effect, i'd put the rolls-royce of tankless heaters (the 'Mobius' TM-1) for about $2,000... and get the 8.3 gpm rate. In a boondock situation, a nice hot, high pressure shower would go through my week's supply in a couple of minutes...unless i set up the SofTub as a rainwater collector/cistern, or ran a suction line over to the nearest river/stream/creek... Tuna To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
