Hilkoil to heat exchanger info needed

 
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lsayre
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Post by lsayre » Tue. Sep. 18, 2018 8:27 pm

Based on Lightning's calculations he'll be hard pressed to heat 3 feet of hot water baseboard.

 
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lsayre
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Post by lsayre » Wed. Sep. 19, 2018 9:09 am

Lets look at this from an admittedly well oversimplified surface area perspective:

A stove with a firebox dimension of 12 x 18 x 22 has a surface area of 1,752 square inches.
A 30 inch water pipe of 1" diameter has a surface area of 95.8 square inches.

95.8/1752 = 0.0547

If the stove is generating 35,000 BTUH, and 20% of the heat is being sucked out the chimney, and the rest is being absorbed by whatever surface area it hits (and then later radiated), then the pipes exposure is:

35,000 x 0.80 x 0.0547 = 1,532 BTUH available to the water pipe

 
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Lightning
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Post by Lightning » Wed. Sep. 19, 2018 12:11 pm

Another thing to consider Larry is that at most, only half of the pipe is facing the fire to pick up radiant heat directly from the source. The other half of the pipe, not facing the fire, can only pick up heat thru conduction via the hot gases around the pipe. Whereas, the entire fire box itself has a direct line of sight to the heat source for radiant heat, the pipe however does not. So I wouldn't expect to get the full 1500 BTUs that you figured.


 
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lsayre
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Post by lsayre » Wed. Sep. 19, 2018 7:35 pm

Lightning wrote:
Wed. Sep. 19, 2018 12:11 pm
Another thing to consider Larry is that at most, only half of the pipe is facing the fire to pick up radiant heat directly from the source. The other half of the pipe, not facing the fire, can only pick up heat thru conduction via the hot gases around the pipe. Whereas, the entire fire box itself has a direct line of sight to the heat source for radiant heat, the pipe however does not. So I wouldn't expect to get the full 1500 BTUs that you figured.
And another thing to consider is that 35,000 BTUH requires eating ~2.85 lbs. of coal every hour. Or about 68.5 lbs of coal per day. Others will need to chime in to tell me if that sounds like more or less coal than they burn on an average day, or if it is about the norm.

 
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Lightning
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Post by Lightning » Thu. Sep. 20, 2018 1:27 pm

My average is around 60 pounds per day. Some days less, some days more.

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