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  1. #1

    Default Steam or hot water oil boiler?

    hi - we have a 100 plus year old house that has absolutely no heat. we have a number of radiators that were originally steam, but could be converted for hot water use.

    the house is located in vermont and there is always a chance of prolonged electric outage and therefore pipes and systems freezing. this is a full time residence.

    what are the best options for efficient heat? Forced Hot water or Steam?

    Which type of new boilers would be better to use - condensing, three phase or modulating and condensing?

    is there a way to determine the amount of fuel each boiler will use per year based on BTU's, EDR and area to be heated.?

    we have always had steam - know how to maintain and find its easier as it lacks as many moving parts as well as being a comfortable heat.

    Also have been told that hot water can be more efficient but cannot find why.

    please help us decide which type of system to purchase. thank you.

  2. #2
    Join Date
    Feb 2008
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    555

    Default Re: Steam or hot water oil boiler?

    My preference is definitely for forced hot water, but I'm trying to get a fix on your current heating situation.

    You say you have no heat now & that you have several steam rads---SOMETHING will have to be put in to make the house liveable.

    I wonder if you have the remnants of a steam system that could be made to work for the time being (including the distribution piping connected to the rads??

    Is there a workable chimney??

    Do you have a fireplace now so you can burn wood for the time being??

    From your post it sounds like natural gas is not available--is there an oil storage tank?? Is there a steam boiler??

    Have you contacted any heating contractors in the area to get some quotes??

    Depending on your location in Vt., it may take several weeks to nail down a contractor who is not busy (busy time of year) and would be willing to convert what you have of the steam system to a hot water system.

    It may take some doing to get the steam rads & associated piping in shape---assuming the rads are suitable, the piping has to be disassembled to remove the steam traps in the return piping & any orifices (both of which will retard the flow of the hot water.

    Often steam piping is rusted shut & has to be replaced.

    The steam vents in the middle of the rads would have to be plugged up & holes drilled in the top of each rad & the hole tapped (threaded) to accomodate a bleed valve to remove air from the hot water system.

    Some heating contractors won't take on such a project if they can't get a solid idea of how long it will take (or the problems involved) so they have no idea what to quote you for the project---a steam system produces only 1-2 psi pressure; converted hydronic rads require 15-20 psi--they often leak when the higher pressure is applied.

    Do you intend to do most of the work yourself??

    You may have to touch base with several heating contractors before you can get a solid idea of the best way to go---it may be hot water baseboard (which is easiest to install), or under floor radiant using plastic PEX tubing (if there is a cellar).

    Part of the deal with the contractor might be to install something temporary like portable heat exchangers(radiator-type devices) temporarily strung together with PEX tubing to provide heat now---then remove them when the hydronic system is installed--perhaps by the end of Nov.

    Some of the sites below explain different hot water boilers and other equipment--most links should still work.

    Condensing are the most efficient & save fuel, but would have a longer payback--they would make sense if you plan to stay in the home over 5 years.

    Three-pass boilers are also excellent, cost considerably less than condensing & have a high efficiency.

    Even the basic cast iron boilers have an 85% AFUE efficiency & cost $1500-$2000.

    The amount of heat a building needs is computed in btu/hour based on the square footage of the building multiplied by a heat factor (30= very tight building, lots of insulation, tight windows--60 = drafty house, no insulation, drafty windows).

    Thus a 2000 sq.ft. house X 40 (heat factor) = 80,000 btu/hour (approx.) to heat the house & the size of boiler needed.

    Do a "heat loss calculation" (sites below) as well as a "fuel cost comparison" to determine amount of oil burned annually.

    http://advice.thisoldhouse.com/showthread.php?t=1639
    http://advice.thisoldhouse.com/showthread.php?t=3820
    http://advice.thisoldhouse.com/showthread.php?t=5571
    http://advice.thisoldhouse.com/showthread.php?t=5085
    http://www.masterplumbers.com/plumbv...vertsteama.asp

    http://www.ednasantiqueshop.com/radiators.htm
    http://www.hud.gov/offices/pih/progr...c/strat_h8.cfm
    Last edited by NashuaTech; 10-28-2008 at 06:39 AM.

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