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oil fired forced hot air fresh air advice

Hi Guy's and Gals, Question for all you guys that are in the field.
My crown forced hot air oil fired furnace is in a small 5.5x9 foot exterior room, (no basement). We are in ct. on a lake so it gets bitter cold. In this room is also my Electric hw heater and my 275 gl oil tank. I added a small grill to the supply side above the ac coil to add a little heat to the room to stop the jelling of the lines and pipe freezing. The ceilings are 17-18 foot high in this room. No insulation, No sheetrock and no ceiling. Open rafters to the soffits.
I've been having problems for years with soot, backups, misfires, lockouts, and my first furnace even ended up with the entire chamber crumbling after about 8 - 10 years. Not getting any advice from my multiple hvac guys over the years. Just bills... Now another hvac guy who doesn't do my service and doesn't want it. (commercial contracting comp.) came by and said there's not enough air in the room. Need to get air in there. Normally like when I remodel a basement I would just do my appropriate size vents, high and low in a interior wall. This here would put me back in the frozen mode for the room if I put them on the outside walls.
Is there a fan with a damper system I can put in there to pull air from the outside into the room or straight into the appropriate plenum or duct that only comes on when furnace is running? Sorry for the long thread but trying to give you smarter than me guys as much info as possible. Also just for giggles.. Want to put in a better air cleaning system. Just the crappy filter on the return end next to the blower is just not cutting it. Thanks ahead of time. And for you smart as*** .... Go easy on me.


  • unclejohnunclejohn Member Posts: 1,420
    You don't sat how many BTU the furnace is. you need a 1" opening for each 1K BTU I believe.
  • STEVEusaPASTEVEusaPA Member Posts: 3,463
    Here's 2:
    Either one of those will work fine, sized and installed appropriately. On a call for heat, the fan comes on, then the boiler can fire.
    I recommend you insulate the room (spray foam might work best) and get some heat in there.
    Bitter cold air and cold oil really affects combustion, so warmer combustion air, warmer oil=better combustion.
    I'm also concerned with the small room, how close is the oil tank to the boiler?
    Another thing I would do is an oil line heater, installed at the nozzle.
  • madman292madman292 Member Posts: 3
    I agree with the spray foam!. But we did put a small register like I said in the supply duct. Helps greatly but still.... The oil tank is only about 3 1/2 feet from the furnace (not boiler)
    Do those units get applied to the return duct system? I would assume so. And if so, I'm considering a new electronic static filter or something of the sort. Would it go before that or after that? And it does get bitter, Bitter cold . If it's 10 degrees in town and the wind is up to 8-10 mph, it's at least 20 degrees colder here on the lake. Wind comes across and it will rattle the back of the home. Blows through a anderson window like it a cheap vinyl replacement. Thanks for the info. And unclejohn, Its a crown furnace with a ez1hp burner. Set with a .65 nozzle, Gives us a approx. input of 96000 btu. We can go up to a 1.00 tip and that would give us 140,000 Couple things we are going to look at. Sizing the home proper, and still need to check the temps in both supply and return to see if we need to ramp up the blower. I believe it's set on low from the factory. When home was originally built we trusted the hvac guy.. He ended up putting that crap fibaduct in and only 1 central return in the entire home. And thats the minor issues. Crazy hot and cold differences between rooms. Unfortunately, it's all up inside scissor trusses. No way to get to any of it, with out ripping all the ceilings down.
  • STEVEusaPASTEVEusaPA Member Posts: 3,463
    Yeah the oil tank has to be 5' away from the burner, or separated by a fire-rated wall.
    The combustion air system, CAS, just goes thru the wall with the duct into the mechanical room. It's wired in series as a safety interlock.
    It pulls combustion air from the outside, which is why I would insulate the room. A register may help, you also would need a small return vent too.
    I would insulate and treat like a regular conditioned room.
    If you're ductwork is undersized, ramping up the blower speed is only going to make it worse. You need to check the temperature drop across the heat exchanger and the external static pressure, before changing blower speeds.
    For best comfort, I would do a manual J & D, and see how far off the ductwork sizing is compared to what it should be-room by room. If it needs to be re-done, unfortunately it needs to be re-done. There are no tricks if your comfort is that bad. Maybe make an access panel on the gable end of the roof, or some access panels in a closet. If you're trusses are parallel in a hallway, you can also cut in pull down steps-just make sure you properly insulate.
    A 1.00 nozzle will give your 140kbtu's at 100 psi pump pressure. based on your .65 (and not knowing your model #, I'd guess the pump pressure is 140psi. If a .65 was putting out 96k btus, the pump pressure would have to be 200 psi, which I highly doubt. I wouldn't over fire the furnace, that will also make things worse and shorten the life of the furnace.
    I'd also hold off on adding any filters that may increase static pressure.
  • madman292madman292 Member Posts: 3
    Wished you lived in my area steve. Could use a good hvac guy.
  • STEVEusaPASTEVEusaPA Member Posts: 3,463
    Check this site for a contractor. There are some good ones up in your area.
    madman292 said:

    Wished you lived in my area steve...

    Not me...I own a heating oil business and hate even the mild-ish winters in the Philadelphia area :) My goal is to retire somewhere warm, fly somewhere to ski about 4 or 5 days, once a year, fly back to warm climate.
    That's about all the winter I need.
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