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Posted by steve on December 11, 2007 at 23:14:46:
In Reply to: Re: steam boiler sizing posted by HeatPro on December 11, 2007 at 21:51:27:
: : ++++ Is it better to go under or over when using the net value. You might be in between boiler sizes or just slightly higher than the smaller size. Can one safely say if it is close go down and let the extra 33% take care of it?
: -- The extra 33% is to allow for the pipe and heating up the mass of the water, boiler, pipe and radiation. Some systems have VERY large pipes, others not. 33% is a good guess; but 50% more than the radiation is also a good guess.
---- I think you are saying size up. Correct? Is there anyway to make less of a guess and have things more accurate.
: : ++++ The sq ft of steam seems to differ quite a bit between manufacturers even for comparable BTU/h boilers. Why is this and more importantly what effect does it have?
: -- you are comparing different boilers made differently with more or less capacity. The boilers are different because the numbers are what the boilers are tested to be.
---- I read this as each boiler can put out the same btu/h, but with different sq ft of steam. That said, there is a reason this value is given in the specs. What is that reason?
: Is using new convertor tables such as those from rittling.com accurate enough for the old convectors? Their convector tables don't seem to convert to btu/h by using a straight EDR*240.
: -- Rittling tables are for their convectors.
---- Is it roughly accurate for a similar sized convector or do I need a manual of convectors to get things more exact?
: And is 240 the best value to use or should one use an alternate value?
: -- 240 is the value used in the old testing labs.
---- Should one still use this value or use a lower value today?
: : ++++ If boiler performance is only boiler related why would the burner matter?
: -- If car ratings are only for the car, why would the motor matter?
---- I read this as both matter, but the boiler will still put out roughly the same heat with an alternate burner.
: : Are there any energy star rated gas steam boilers?
: --Northshore Welding lists gas energy star boilers:
: http://72.14.209.104/search?q=cache:Lg85uSilCrQJ:www.energystar.gov/ia/products/prod_lists/boilers_prod_list.pdf+energy+star+rated+steam+boiler&hl=en&ct=clnk&cd=1&gl=us
---- For gas steam I only see the Rayes. Is this for residential use? It looks like this is commercially oriented. There is also the Burnham C series, but these are too large for my residential application.
I amazed that there are so few efficient gas steam options.