Water Heater...

2»

Comments

  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Water Heater...

    The problem with liquid under high pressure in a sealed bottle, such as LPG, is that the valve on top, also contains the over pressure release valve, the "blow off". If the cylinder is upright and for whatever reason the pressure exceeds the limit (overfilled or over heated etc), the blow of opens and releases vapor only, dropping the pressure back to the safe zone. If that same cylinder is on it's side and the blow off lets go, two things can occur. One, instead of safely releasing vapor, it sprays liquid, which in the case of LPG, boils at minus 40 C when no longer under pressure, causing instant and severe damage to human, or any other flesh it comes in contact with. And two, the blow off is designed to release enough VAPOR to maintain safe pressure, but liquid may not pass through the blow off rapidly enough to ensure the cylinder won't get dangerously over pressured. For these reasons, it is against the law in Nova Scotia to transport propane cylinders, or any other such cylinder containing a dangerous liquid under pressure and with a blow off on the top of the cylinder, in any position other than secured in an upright position. Even if the valve gets broken off, escaping vapor from an upright cylinder produces less of a "kick" than does liquid that might be released from a cylinder on it's side.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Water Heater...

    Bingo, give the man a kewpie doll! That is the reason to carry tanks up right!


    I believe it is a Federal (Canada) MOT rule.

    Tony
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Water Heater...
    icarus wrote: »
    Bingo, give the man a kewpie doll! That is the reason to carry tanks up right!


    I believe it is a Federal (Canada) MOT rule.

    Tony

    Must be; same in NS, ONT, and BC - pretty much covers the country. :D
  • mtdocmtdoc Solar Expert Posts: 600 ✭✭
    Re: Water Heater..
    CDN_VT wrote: »
    I use wood heat in the winter with water heating coils in the collection area of the "Airtight" (wood stove) , a collection tank of 40 gal that in the winter , it's the only way we heat the water. It gets hotter than the DWH , and we must either do a load of laundry, or get dirty so "we" need a shower ;) .
    It's in the summer that Im installing a split vacuum tube solar collector to work the same collection tank as the airtight use's.

    VT


    I'd love to hear more about your system. I'm hoping to do something similar. I currently have a standard electric hot water heater and a small electic on demand system supplying heat for closed loop in floor heating of a partial basement. None of this is backed up by my solar system for obvious reasons.

    In an effort to become less reliant on our not- so - reliable grid connection, my plan is to set up a system like yours. A coil through our woodstove for the winter and solar in the summer, with on demand propane as backup. Any tips would be welcome.- especially about your wooddstove setup. There seems to be very little about how to do this on the web.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Water Heater..
    mtdoc wrote: »
    There seems to be very little about how to do this on the web.
    try searching 'range boiler'
    read a lot... they can explode!
    mtdoc wrote: »
    A coil through our woodstove for the winter and solar in the summer, with on demand propane as backup. Any tips would be welcome.- especially about your wooddstove setup.

    I have set up at least a dozen woodstove range boilers. All of my systems have been thermosiphons.

    My first several systems were external to the woodstove. They worked very well, but need 2-3 feet of copper.

    When I started building internal systems, I used all brass or stainless (just a 5-8 inches).

    In all my systems I put pressure temperature relief valves on both input and output of the heating coil (not literally a coil).

    If you have hard water, they can become obstructed.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Water Heater..

    Proper t&p valves, and expansion tanks are essntial for a safe installation. I had one for years with a thermos siphon system, until we built he new house with its new stove. It was just too much trouble to design the system for the new stove and house, I will revisit it at some point.

    Tony
  • mtdocmtdoc Solar Expert Posts: 600 ✭✭
    Re: Water Heater...

    Thanks for the pointers vtmaps and Icarus. Understood about the need for good pressure relief valves and the explosive potential if not done right!

    I'm not sure a pure thermosiphon will work for my situation. Current utility room with current water heater and on demand boiler/expansion tank for in-floor heating is located in basement - below the wood stove. Any experience using circulating pumps?

    I'm a total noob when it comes to all but the most basic plumbing.. Will need to find a plumber locally who is willing to help. I'm not sure any nearby have experience with this - and especially with combining it with solar hot water.

    There's a fair number of people with woodstoves here but no where near the number as in Vermont. I love Vermont! I lived just outside of Burlington for 4 years. Nothing like burning New England hardwoods in a good Vermont Castings stove. The Doug Fir here just does not last through the night like a stove full of Vermont maple will.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Water Heater...

    A simple differential controller and a grunfos circ. pump will work fine. Azel l makes one for solar water heat that would work fine, as does gold line, I'm sure there are others.

    http://www.azeltec.com/images/brochuredst932.pdf

    https://www.hayward-pool.com/prd/About-Goldline-Controls_10201_10551_15004_-1___.htm

    Tony
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Water Heater...
    mtdoc wrote: »
    Thanks for the pointers vtmaps and Icarus. Understood about the need for good pressure relief valves and the explosive potential if not done right!

    I'm not sure a pure thermosiphon will work for my situation. Current utility room with current water heater and on demand boiler/expansion tank for in-floor heating is located in basement - below the wood stove. Any experience using circulating pumps?

    I have no experience with pumps. You could do a 'hybrid' system... thermosiphon to a tank by the stove and use a pump to move hot water from it to the basement tank. If the tank by the stove is uninsulated you will add a measure of safety to the system because if the pump fails the uninsulated tank will be a radiator. If you size it right the fire will go out before the pressure-temp valve blows.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • 706jim706jim Solar Expert Posts: 371 ✭✭✭✭
    Re: Water Heater...

    Not much action here for over two years, but, hey, I'm new here......

    I have an island cabin and use a 6 gallon propane fired RV heater for hot water.

    12000BTU/hr input will usually heat the tank in around 30 minutes.

    A main reason that I went with this style of heater is feeding it propane when I have to carry the tanks. I've gone from 100# to 60# to 50# tanks as they have to be carried aboard my boat and it is getting harder to do as I age.

    This style of heater can be installed outdoors and this has worked out well for this seasonal cottage.

    It would also kill me to leave 30 or 40 gallons of hot water to cool off when returning to the city following a weekend whereas 6 gallons doesn't seem as wasteful to me.

    In our climate (Ontario Canada), those tankless heaters have proven to be more trouble than they are worth. As others have mentioned, they are fussy with regards to hard water and they are also unhappy about starting on propane when the temperature drops to -40. One mechanical contractor I know well actually removed his tankless heater and installed a conventional storage tank in its place.

    As readers may have guess, mine is a seasonal residence, used for about 6 months of the year and dormant for the winter.
    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 27th year.
Sign In or Register to comment.