Brandon H Hicks
New Member
Hi guys,
I need some help choosing a boiler/DHW system for a new wood shop that we’re wrapping up framing soon on. My plumber and I were considering a Navien NCB-E 150 but I’ve come across a few Navien horror stories on these forums and it has me second guessing that decision.
I'll share a few details about the building...
The shop is about 800 SF. Radiant heat is via a 6" concrete slab with 4 equal loops of 1/2" hePEX on 9" centers - about 1,000 ft total. Walls are insulated to R21 and the 14’ cathedral ceilings are to R49 and we are in climate zone 6. There are some fairly large windows but they are Argon filled double-paned Pellas so the building is pretty tight. It will have a small kitchenette as well as a bathroom where we did go ahead and plumb for a shower as well. Fuel source will be propane and I am also installing a wood stove since we’re on a large wood lot with an endless supply of free firewood.
The shop will be mostly used on weekends until I retire and because the thermal lag on radiant heat is so long, the plan is to basically use the boiler for domestic hot water (not much) and freeze prevention to keep the building around 50 degrees or so and then use the wood stove to warm it up when in use above that. I’ll probably go ahead and add a supplemental electric heater to the bathroom as well since I’m pulling all the electric myself and hey, what’s another 20ft of 10/2?
Anyway, is this Navien unit overkill for this use? Even the smallest one isn’t cheap and I’m concerned that even that may short-cycle with the amount of thermal mass we have and how tight the building is but I don't really know how to calculate all that.
Thanks for any advise.
I need some help choosing a boiler/DHW system for a new wood shop that we’re wrapping up framing soon on. My plumber and I were considering a Navien NCB-E 150 but I’ve come across a few Navien horror stories on these forums and it has me second guessing that decision.
I'll share a few details about the building...
The shop is about 800 SF. Radiant heat is via a 6" concrete slab with 4 equal loops of 1/2" hePEX on 9" centers - about 1,000 ft total. Walls are insulated to R21 and the 14’ cathedral ceilings are to R49 and we are in climate zone 6. There are some fairly large windows but they are Argon filled double-paned Pellas so the building is pretty tight. It will have a small kitchenette as well as a bathroom where we did go ahead and plumb for a shower as well. Fuel source will be propane and I am also installing a wood stove since we’re on a large wood lot with an endless supply of free firewood.
The shop will be mostly used on weekends until I retire and because the thermal lag on radiant heat is so long, the plan is to basically use the boiler for domestic hot water (not much) and freeze prevention to keep the building around 50 degrees or so and then use the wood stove to warm it up when in use above that. I’ll probably go ahead and add a supplemental electric heater to the bathroom as well since I’m pulling all the electric myself and hey, what’s another 20ft of 10/2?
Anyway, is this Navien unit overkill for this use? Even the smallest one isn’t cheap and I’m concerned that even that may short-cycle with the amount of thermal mass we have and how tight the building is but I don't really know how to calculate all that.
Thanks for any advise.
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