atmospheric boiler for coach house?

metrorental

hello,

i want to replace an aging boiler in an insulated/drywalled coach house with 3 bay garage on first floor. it has cast iron baseboard below and cast iron radiators above. i'd like to use a lochinvar solution boiler with bvent through the roof. is there a problem with using this in a garage install if the boiler is installed 2' off of the floor, plus if needed, a closet enclosure with outside air intake vents.

all opinions would be welcome.

thanks, metro

Limamikemike

Perfect for a modcon

Sounds like your set up would be perfect for a small modulating condensing boiler with outdoor reset because:



-sounds like your space is limited, wall hung boiler will save space.

-you are going to bring outside air in anyway so keep the envelope tight and install a boiler that has a connection for outside air.

- On milder days all that cast iron emitter you have will cause that modcon to condense a great deal boosting efficency provided you use outdoor reset

-b vent is expensive so what you might save on an atmospheric boiler you spend on the venting.



Get some one to do a heat loss calc on the structure or do it yourself using a number of programs on the web. You'll find out you probably need less boiler than you think therefore using less fuel in the first place.



Lochinvar has several nice wallhung boilers. Check out their Cadet and WHN series knights.

Bob Bona_4

perfect

Response from Lima. The extra cost on the modcon is a wash when you factor in the cost of a chimney.

metrorental

garage install

thanks for the responses. Do you think it's safe and / or code compliant to install an atmospheric boiler in a garage if it is raised up min 18" from the floor.

RobG

No!

No! You need a unit with sealed combustion, especially if there is a living space above. It may not be code in your locale, but it is the only safe way to do it. Use a modcon and save space and money on fuel (you don't have to put another hole in your roof either, usually).



JMHO,

Rob

metrorental

it's about cost and reliability

i can buy the cbn045 for much less than the knight and it already has the primary built in. i can reuse all the existing disribution piping. i can build a cheap wall and door in the corner and bring in outside air through the outside wall.

i keep hearing that a simple 84+ boiler will be much more reliable in the long term.

space is not an issue.  this is in chicago btw.

thanks for all the opinions

John Mills_5

Huh?

Can't use a conventional boiler in the garage? That a local code? There are oodles of homes around here with boiler in the garage. For the outrageous price of a mod con with the extra piping, nobody wants to spend that. We go back with an 80% cast iron boiler. No problems here doing that. Just get the burners 18" up like we would with a water heater or forced air furnace. 

Limamikemike

Equipment cost

Have you gathered quotes for an install of a atmospheric vs a modcon or are you comparing just the boiler cost?



Where I live (Canada) there is no code against properly installed atmospheric appliances in a garage and truthfully that's pretty much how it's done here with unit heaters. However rules change when there is a living space above. Try to get someone reputable in for a look and quote both installs, and positively tell you what you can and can't do in your building.



Does the old boiler produce DHW for the living space above?

metrorental

dhw

DHW is by an electric on demand unit for 1 bath and 1 kitchen sink.

it's a finished garage with small apartment upstairs. parking for 1 car

and some shop space for me. is it a problem to have an atmosphere boiler in a sometimes dusty shop space?

the quotes i got were much less for the lochinvar solutions cbn045 with 2 stage valve using existing piping, with a 15' bvent through the roof, and much more for a lochinvar knight 055 with new piping distribution, 1-10v pumps and zone valves.

the price difference is significant.

also, i'm also concerned about the long term reliability of the mod/con vs the no frills atmospheric.

RobG

Dear John

  John, I don't know about your locale, but where I live we are not allowed to install any appliance with an open flame in a garage, 18" off the floor or not! I would not risk my company, my license or my conscience in doing so. Please do not advocate bad advice. This is straight from the Lochinvar manual for that boiler.





DO NOT install this appliance in any location where

gasoline or flammable vapors are likely to be present.



I don't know about you but I keep two cars, lawnmower, weed-eater, yada, yada ,yada,........ in mine.



To the OP, go with a wall hung a mod-con and don't worry,be safe. They do make sealed combustion power vent boilers, however, by the time you assemble the stand and wrestle a hunk of cast iron onto it and vent it, you've offset the cost of the mod-con. If you go with a fire tube heat exchanger you can probably pipe it direct rather than primary / secondary.



JMHO,

Rob

metrorental

garage install

hi rob, thanks for your advice about the safety concern. i care about that as well. i'm a builder (not hvac) and know that we have often built small closets in attached garages for furnaces. the inspectors were concerned about transmission of fumes throughout the house. they have however allowed boilers and unit heaters without enclosures.

this is for my coach house and of course the price difference is quite significant.


thanks again

Limamikemike

Zoning

Apologies posting pricing is not allowed. Its possible to get an idea of costs with out putting numbers out for all to see.



But, myself having some idea what things cost (I design systems), I would venture to say that the lower quote that the gentleman/woman's labour was pretty much free. We're the quotes from the same people?



How is the garage currently zoned Up/dn? Separately pumped etc?



No I would not install an atmospheric appliance in a dusty area, definitely not a shop area. An atmospheric appliance uses air from the space for combustion if that air is contaminated with a combustible product such as dust, fuel vapors, lawn chemicals etc, fires can occur, and as was mentioned goes against manufacturers instructions. Hence the need for a hole in the wall for combustion and a enclosure for the boiler.



Gather a couple other quotes and since you seem hooked on lochinvar compare a Cadet CDN 040 boiler to the Solution CBN 045. They quoted a Toyota vs a Ferrari. the solution has most of the components a modcon has anyway minus the blower (and you can get one for it) so I feel the reliability point is moot. Besides a Knight WHN 055 can be piped direct per manufacturers instructions which eliminates primary/secondary if your situation allows.



When they come to quote tell them exactly what you told us, it will quickly weed out the people who just want the work and the guys who want to give you a good safe and reliable system.

Bob Bona_4

agreed

By the time you build a room, fire door, chimney etc you have made up the diff and gained much more with a mod con. Reliability is a non issue. Pretending I didnt see the pricing I will say the atomospheric option is way low. I can't even see the B vent work in that. Might be worth a look at a combi modcon like Triangle Excellence or Laars and dump the electric dwh?

John Mills_5

Local

Never heard of that particular boiler and if it says don't put in a garage, it shouldn't be put in a garage. In our area, in a lot of parts of town, most equipment is in a garage regardless of what it is. No new boilers are being installed but the average smaller new home gets an 80% furnace and thousands are replaced each year. Many 90s in garages don't have outside air for combustion. Not putting an open flame in the garage may be a local code but if it is acceptable in an area I can't see how a contractor is risking his license doing it. Same with water heaters. Now they have the flame safeguard but are still using garage air for combustion. 

metrorental

reliability


the two issues are really price and reliability.

as i said i don't install hvac, but have heard many stories about parts and service failures with them. in out work, we have speced and built with 80+ and 90+ furnaces, and have always had many more service and warranty calls with the high efficiency models. i would assume the boilers are the same. i have an atmospheric buderus in my house for 19 years, needing only cleaning and checks, without 1 breakdown.

thanks again for all the thoughtful responses

metrorental

garage install

the dust and conditions in a shop are not ideal.

the following is from the lochinvar install sheet for the cbn045

4. Appliances located in a residential garage and in adjacent   

spaces that open to the garage and are not part of the living space of a dwelling unit must be installed so that all burners and burner ignition devices have a minimum clearance of not less than 18" (46cm) above the floor. The appliance must be located or protected so that it is not subject to physical damage by a moving vehicle.