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High efficiency

High eff. 94 afue direct vent hot water gas heater in an unheated crawlspace? Pa zone 4 sometimes 5 lol

Comments

  • Jamie HallJamie Hall Posts: 10,672Member
    And... ? Is this a water heater application, or a boiler?
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • mikeg2015mikeg2015 Posts: 851Member
    It’s a bad idea to put any HE system in an
    Unconditioned Space as
    Drains can freeze. But is this a mostly sealed or vented crawl? Does
    It have exposed water lines already?
  • Frankcreo_777Frankcreo_777 Posts: 4Member
    Its a breezy wet drit space. Single longest copper line freezes onec or twice a year uninsulated. Just installed a rinnai gas tankless water heater with pex and its heavily insulated. Fingers crossed. 20 yo steam slant fin with dhw crapped out last year. A wall mounted hot water baseboard set up it a bit riskier for the work/money investment.
  • Frankcreo_777Frankcreo_777 Posts: 4Member
    Jamie. Already did a hot water tankless. This would be its first winter. Aiming for a boiler baseboard switch. Can enyone speak to the efficiency of hydronic baseboard over steam? Half? I have a very small 700 ish sq ft house.
  • Jamie HallJamie Hall Posts: 10,672Member
    Two in one day. Sigh... assuming equally modern, equally well installed, controlled, and maintained steam and hot water systems, the maximum efficiency of a steam system will be around 86%. If the hot water system is powered by a mod/con, it can, under certain conditions, reach as high as 96%, less pumping losses -- but only under certain conditions.

    I would expect that on the whole, the best you could expect from a hot water baseboard system would be that it might reach 5% more efficiency than a steam system. In hard numbers, if a steam system burned 950 gallons of oil in a year, one might expect the mod/con to burn 900 -- a 50 gallon difference.
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • ZmanZman Posts: 4,997Member
    If you are looking for feedback, you may need to slow down a bit.
    Have you removed the steam yet? What is/was wrong with the steam system? Have you considered improving the insulation and air sealant in the crawl space? What type of boiler are you considering for your conversion?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JohnNYJohnNY Posts: 2,293Member
    In a 700 sq ft house, it's not going to pay back in any appreciable way that would attempt to justify its cost. However, if you want the control and flexibility of a hot water heating system which would for some reason work better for you over that of a steam system, then that would be the only reason to convert to hot water.
    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
  • Frankcreo_777Frankcreo_777 Posts: 4Member
    Zman. It was a 25 yo slant fin. Cracked with water pouring out. Not gone yet. If i switch to hot water i can do most of the prep myself via pex and hanging the wall unit and a 1500 credit from the gas co. Fir a unit 94 afue or greater. Hopefully savings as well in the long run. If i stay steam its more expensive, no credit, no savings and its out of my hands. Even if i can prep to cut costs by breaking up and removing the old unit theres no way im getting a new unit into that crawlspace. Wouldnt be safe for a noob. I cant afford to condition the crawlspace professionally. Its a dift/ wet space with a pump. 3 sides cinderblock foundation. One wall stacked stone very loosly with lots of spaces. I laid vapor barrier on the ground and sealed as many holes as possible. Not as bad as direct wind but def freezing.another vote for steam in my mind is the warranty on a decent steam unit as opposed to a wal mount high eff boiler. 25yr? on slany fin galaxy at a good price. Thoughts?
  • Jamie HallJamie Hall Posts: 10,672Member
    I'd still stay with the steam... even with the ratepayers paying part of the bill to change, I doubt that you'd really save much money -- if any. Especially if you have to add radiation to compensate for the lower output of hot water.
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • hot_rodhot_rod Posts: 11,684Member
    did you run a heat load calc? That would help define what you need for emitters and boiler size
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
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