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Tight space for boiler system

A small new house is being designed, built atop a 4-foot-depth crawlspace.  It is desired to place all mechanicals in that crawl space, as there is no room for a mechanical room in the living spaces above.

The thought is to locate the system, proposed as a small mod-con wall-hung, under the staircase area, so as to provide more overhead, and permit getting the exhaust/intake flue up and out an exterior wall at an acceptable height above finished grade outside.  The site is in upstate NY's Adirondack region . . . snow country.

The image here is a section cut taken through the model to try and show the proposed space.  The figure in the model is 5'-10" tall, and the boiler is scaled to match the size of a Veissemann Vitodens 100.

Access to the space would be via a full-sized 30-inch width door,  behind the man-figure shown, and then down a vertical ladder to the crawlspace floor below.  You can see to the L of the boiler how the staircase space encroaches down, and how elsewhere, all in the space, the overhead is about 48 inches.

The system is expected to be relatively simple, with about 8 panel radiators all with TRVs supplying heat to the various spaces on the floor and a half, above.

Does this look OK?  If not, what should we do?


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853

    i HATE crawl space jobs. Too many things to go wrong without being able to see and or hear them.

    I realize that architects don't take the need for service and access into consideration. They are not the ones who actually have to perform this service. If they were, they would FIND space somewhere to allow ease of access.

    But those are just my personal experiences and reflections having been there and done that.

    In Germany, the appliance is typically mounted on the wall of the kitchen, just like the refrigerator, range, oven and microwave. Maybe the upper half of a broom closet?

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Jamie Hall
    Jamie Hall Member Posts: 22,953
    I have had installations

    to work on which were very like that.  They do work, of course.  They are also nightmares to work on and service -- unless you happen to be a former US Navy machinist's mate on a submarine, in which case they might feel just like home.  Which often means they don't get serviced.  However, as Mark says... the client is the boss.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EricAune
    EricAune Member Posts: 432
    Have had a few like this

    Pipe insulation is a must in a situation like this.  Trapping all the heat the system piping will emit under the stairs can cause problems with any areas close by.  It goes without saying that they are less desirable to install and service but not impossible to pull off.  Sometimes we get stuck into thinking a huge wall is needed for dramatic display of our skills if not for ego boosting alone. 

    This type of installation will force creativity and truly show the piping skills of the installer.  I often admire the skills of those who are able to pull it off well.  I'd go for it, in most cases it will be easier that working off a creeper or skateboard (if the crawlspace has a floor) and definitely better than kneeling for two to three days.
    "If you don't like change, your going to like irrelevance even less"
  • R Mannino
    R Mannino Member Posts: 440
    It Can Be Done

    but it can make service a PITA. This one is in a very small basement about 12' x 12' headroom isn't the greatest either, but it's enough room for the mechanicals.
  • rich pickering
    rich pickering Member Posts: 277
    edited December 2009
    that's better Gene

    Being able to stand up is much better.  But, check on required clearance in front of the boiler. It's going to be tight. Are you able to put it on the cutaway wall?

  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    edited December 2009

    What about the condensate and relief drains?  You may need a special sump pump. The Vitodens top of boiler is typically 78" from fin. floor.  That dimension can be lowered, depending upon LLH placement and piping access below the appliance. 
  • Big Ed_4
    Big Ed_4 Member Posts: 2,712
    edited December 2009
    I Would....

    .... try the smaller wall hung upstairs and and drop the larger indirect in the crawl .. No need to spend too much time down there ..
    I have enough experience to know , that I dont know it all
  • bob eck
    bob eck Member Posts: 930
    boiler in crawl space

    check into using the Triangle Tube Prestige Excellence 95% gas boiler.

    It is a 110,000 btu gas boiler with 15 gallon built in indirect water heater that delivers 180 gph of domestic hot water.

    could be hung in a closet on the first floor. vents with PVC pipe.

    Great unit I have one in my house.

    Can get 5 or 10 years parts and labor warranty as a extra.

    check it out.
  • Pete2014
    Pete2014 Member Posts: 1
    Heating help for summer home

    I have a friend with a summerhouse in cold northern Maine which is closed in the winter. The boiler is winterized when the hose is closed(pipes and boiler drained, and antifreeze in traps etc). House has a granite foundation, and basement is a combo dirt crawl space with a cement area where the boiler is located. In the winter there is alot of condensation, and spring thaw creates a small flow of water in the basement to the old drain in the floor. Boilers which remain hot all year can last 40-50 years, boilers in the above condition last up to 10 years.

    My question is how to protect the boiler from corrosion etc while it is stored the winter. Should I build a room around the boiler and controls and vent the space?

    Would draining the heating loops, and running the boiler a very low temp(120) work? (use oil in winter)

    How about fill the system with PG and use electric to heat the loop at a low temp(above ambient) to keep the system dry and keep condensation away?

    Any ideas which experience shows to work?


  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    edited January 2014
    If it's fired by Propane..

    NG appliances are allowed in a crawl. Propane appliances are NOT!!

    Very difficult, if not impossible to pipe in a mod-con with 4 ft or less space. Most units pipe from the bottom making the project a belly-up experience. Expect increased costs for the installation due to lack of space.

    Don't know why I'm replying to a 5 year old thread...