Vacuum steam conversion

FredS

As a research project, we are looking into the possibility of converting existing old multifamily low pressure steam systems to vacuum systems. The motivation for doing this is to gain the benefits of greater efficiency and comfort possible by creating steam at lower temperatures with faster distribution, and reduced water consumption.



If anyone has any thoughts on the feasibility (or impossibility) of accomplishing this, please post them or contact me. We would be interested in what obstacles would have to be overcome, design details necessary to make such a conversion work, what the realistic benefits might be, and the long term viability (maintenance issues) of the system.

jpf321

you may ..

you may find this very interesting .. it's in Dan's off-wall library.

http://www.heatinghelp.com/files/articles/1336/121.pdf



jpf

Jamie Hall

There were

several vapour vacuum systems which the Dead Men used -- the Paul system comes to mind, along with the Eddy and Moline systems, among others.  In addition, many vapour systems operated at a partial vacuum towards the end of their very long firing cycles (coal burning).



I have to admit that I am not a big fan of assisted vacuum systems, simply because I am very much of the KISS school of engineering -- and a vacuum pump is either anything but simple (mechanical) or somewhat inefficient (e.g. ejectors).



Pay very close attention to your thermodynamics as you research this, and also your overall system efficiencies.  Just off the top of my head -- I haven't cranked the numbers -- the only efficiency gains that I can see will be in reduced heat loss (from the lower temperature steam) in the distribution system.



In the real world of heating, reliability and simplicity count for an awful lot.

jpf321

and also..

well the decreased temp caused the rads to put out less than 240btuh .. but i would think that a bigger benefit would be that the steam gets sucked to the rads faster in a vacuum system ..



originally, as Dan mentioned the other night, the vacuum system allowed for piping which was 2 sizes smaller to be used .. that was a great installation improvement over 2-pipe .. and he also said quite emphatically, because of this pipe sizing difference, you can never convert a vacuum system to another type once it is in place without repiping the job.

jpf321

another off-wall article dan had stashed away ...

this may be of some interest as well ..

http://www.heatinghelp.com/files/articles/1310/128.pdf