Has anyone used a Munchkin Boiler? I’m in the Boston area, and our HVAC guy is specing a T50 Munchkin for an 1100 sft apt. I’m used to Burnhams vented up a chimney, but we have to direct vent here, and this is what he’s recommending.
Anyone have any experience with these?
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Replies
bk1000'
I don't install them, just have been on the receiving end of one. They are quiet, the circulator makes more noise. And (from what I have read) can fire up or down to match what is needed for BTU input. Unlike an oil fired boiler that is all, or nothing. They are small, for your square footage it would probably hang from the wall. Mine was 24x24 and sat on cement blocks. The one I had installed was propane. Propane is at $1.95 per gallon at this point, oil is at $3.11. I can't imagine that oil could be more cost effective. If anyone has numbers on BTU output oil/propane, I would love the feedback. I have heard The Munchkins are finicky as far as gas input(pressure,etc), and power supply. We had a brownout, and the boiler failed to come back on after. But during a blackout it did fine. I'm sure some plumbers will chime in, with more experience than I have with Munchkins.
Northeastvt
I have one I installed last year and I like it. It's quiet and does the job. I have it wall-mounted. Pretty much as maintenance free as you can get.
One tip -- the screws that hold the burner cover on are stainless into an aluminum casting. Pull them out ASAP and put some anti-seize lube on them (repeat every year or two) or they'll lock up on you and you'll pretty much need to replace the whole burner unit if it ever needs serviced.
I hear the Boderus are good too, but I have not experience with them.
Mike Hennessy
Pittsburgh, PA
Thanks for the input. We have gas coming in off the street, and that's what'll fire this boiler.I wonder if the T50 (the smallest they make) acceptable for 1100sqft. It says the input BTUH is 18-50K and the DOE Capacity is 16-46K. I have no idea that that means, though, in terms of it's ability to heat a (150 year old) home in the Boston area (first floor of a 3 floor two family house)
The T50 is the one I have. It's hooked to radiant floor tubing in a 3-story addition for about 450 sq ft. It doesn't break a sweat with that load. However, square footage is only one small component in calculating how much furnace you'll need. You also need to figure in insulation, window & door openings, etc. This calc will be further complicated by the fact that this unit will suppliment some other heat source in the building. I suggest you get someone to do a heat loss calc for you.
The input is how much fuel the unit will burn. The output is how much heat the unit puts out. The difference is the amount that goes up the stack or, in this case, out the PVC pipe to your yard. The reason the numbers are stated in a range is that this unit is progressive -- it can work at less than full capacity if full capacity is not needed to save fuel.
I can also unequivocally state that, *done properly*, radiant floor heat will make a room way more comfortable to be in at the same, or lower, temp than just about any other heating method.
Mike HennessyPittsburgh, PA
edit: I am assuming that you'll be running your tubing under the first floor. This is a very important aspect of the installation and one that, if done wrong, can really degrade performance. If the tubes are under the floor between the joists, I'd suggest using a system that incorporates aluminum plates (like Uponor Joist Trak) for heat distribution, and carefully insulating under them (the basement ceiling).
Edited 11/15/2007 8:24 am ET by MikeHennessy
Thanks Mike. Actually, we are using baseboard hot water, as the age of the house and the way current systems and beams run under the floor, it's not possible to use radiant floor heating.I am aware of the basis or inputs of the requirements calc, but I don't actually know how to do them, and that's my concern. The apartment is on the bottom floor, where 800 square feet is in the main portion of the home (with a floor above) and 300 sqft is in a single story addition. In all, there are 16 windows and 3 entry doors (though the entry doors all enter into enclosed porches, and are not directly exposed to the outside). There is also a door to the unheated basement below. It is an old, old house with barn board sheathing, and an unknown mix of insulation. To date, we've found both fiberglass blown-in in the walls and some silver backed foam sheets applied between the sheathing and clapboards. In the single story portion, it appears that there is insulation in the ceiling, but the attic space is not open, so it's difficult to know how much.I'm replacing all the windows with vinyl, but still the house can't be air tight. It just seems to me that the smallest possible boiler might be too small, but I really don't know anything about system sizing.Any advice or any good links to web sites would be appreciated.
Well I'm in the same boat you are regarding not being able to do heat loss calcs. I rely on my dealer (whom I trust) to do them. They have a computer program that takes all the variables into account. Your installer should be able to run one, or have one run by his dealer, and give you the print-out.
Sounds like you might wanna talk to an insulation contractor. If it was me (and it ain't), I'd consider blowing celulose into your walls and adding some between the first floor and basement if at all possible. Good insulation may be even more important than new windows.
What's heating this space now -- the boiler you mentioned in your first post? If so, what's its rated output and has that been sufficient?
Mike HennessyPittsburgh, PA
We just purchased the house in Sept. We were told downstairs ran cold, but we are replacing all the windows with vinyl (16 in all) so that will probably help (windows we are replacing were at least 50 years old. They had the old weights in pockets. etc. Single pane, with huge gaps between sashes and sills, etc.)We are also converting from oil fired forced hot air to gas fired forced hot water baseboard. This will also allow us to better seal the floor from the basement space, which is unfinished.It's a long story, but the HVAC contractor we are bringing in is someone we haven't used for heat before (only a/c). He had a fairly low bid, and his timing was better than others, so we went with him. I am sure if I go back and question the size of the boiler, then he'll try to ding me for more money for a larger boiler, but my feeling is his bid should include a properly sized boiler. So, I am just trying to get some facts before I go back to him. If this t50 Munchkin is fine for our needs, I have no complaints, but it just seems undersized to me.I used a calculater I found on-line, and it says I need 60K BTUH. The Muchkin says it outputs 46K DOE Heating. How do you make the conversion (frankly, I'm not sure what DOE is)
I think "DOE" is just the "Dept of Energy" rating. 46K is the heat output into the pipe that the unit is rated for.
If you aren't comfortable with 50K, why not ask about going up to the T80? It's only about $300 more. See here: http://www.munchkinboiler.net/
And, since this is a progressive-firing boiler, the low end (19) is only 1K Btu more than the T50 (18). It's the same physical size as well.
I'd still think hard about getting your insulation package spruced up a bit. Next year's project? ;-)
Mike HennessyPittsburgh, PA