Steam Mini Tube/hybrid/vacuum??

SteamCoffee

Just saw Gerry Gill's great video of a Cast Iron radiator hooked up to his minitube system. He mentioned that it worked so well, he would have gone with it in the whole house had he experimented before. Sounds great, wondering if this idea has gone further with anyone? Seems that vacuum to the system would make for better temp control of the rooms (ie no 220 degree radiators with a call for heat on a mild day) Any thoughts on how to gat a vacuum source small enough for residential projects/retrofits? VariVac controls? T

vaporvac

Link?

would you have the link to that video? I didn't see it with Gerry's youtube ones.

JStar

Vacuum

This has been on the collective concience of The Wall for a while now. First one to make an inexpensive, easy to install / easy to service vacuum system with little to no moving parts will win their place in our hearts and the future history of steam heating in America.

SWEI

Newfangled vacuum/vapor systems

My interest is in finding a way to "vacuum upgrade" existing two-pipe steam systems.  I suspect that radiator orifices, some kind of return trap or loop built from currently-available parts and a modulating (perhaps even a two-stage) burner would do it.

ttekushan_3

Gerry's radiator, passive vacuum, active vacuum.

The idea of running a single pipe radiator "backwards" from the vent line was discussed a couple o' years ago on the subject of Gerry's minitube system. Seems single pipe people felt left out! Seriously, the question was whether a virtual downsizing of a steam system was practical with a minitube arrangement (it was) but what to do about single pipe.



So Gerry is the first to implement it, and with great success. In retrofit, the thought was to run new mini lines to the radiator vent positions and utilize the existing supply lines as the return. Plenty of places for vacuum leaks, though, if converting to vacuum op as well.



I currently have in service an experimental vacuum return station that provides mild vacuum return and 2' condensate lift for a steam sub header that serves about 410 EDR. The lift is into a former vacuum return. It sits a couple feet below the return, at the end of about 200 feet of undripped 3" main. You can just imagine how well that was working out. The original Webster lift fitting was gone.. Until such time that a new vacuum return is restored for 17,500 EDR, I had to come up with something. The arrangement uses generic hydronic components of VERY economical cost. Basically an immersed recirculating but open loop jet pump powered by a cheap cartridge circulator. The single piece cartridge circ's been working fine since it operates on the "clean side," condensate only. It's been running 2 years without flaw.



In the next week or two, a two pipe system nearby is going to get the same treatment, but this time the vacuum pumping station is not required to lift condensate into the boiler return, so it's going to be arranged a little differently but with the same ingredients. Orifice plates will be installed. Originally I looked at the system due to some water hammer on start up and a long lag for return, causing boiler flooding. The supplies and returns are nearly the same level and the end-of-main drip trap has little static height above the return. The returns are dry and ceiling level up to the boiler room. "A HA!" i thought. "Perfect place to experiment!" The owner is excited about it too. The active vac return should solve all the basic problems of uneven heating, start up hammer and slow return. The question will be if passive vacuum can be induced without causing cartridge pump cavitation under higher temps AND vacuum. (And whether cartridge pump seals will be destroyed under vacuum conditions. A two piece may be necessary).



The same arrangement could also be a suitable substitute for a Paul system return.



It could easily be put together as an inexpensive packaged unit, field installed in a number of configurations, including standard two pipe to vapor conversions, minitube construction and Paul operation. The idea is to eliminate the pick up factor among other benefits. I'd guess a conversion would save 30% on fuel consumption even without deep vacuum operation. This is based on vacuum return system installation studies by Oak Services (the people who do the Nash Jennings heating systems).



I'll look for the photos of the experimental pumping station currently in "beta test" and the basic diagram a little later.



Links to Gerry's excellent stuff!



http://www.youtube.com/watch?v=d6BHXov_BW0&feature=youtu.be



http://www.gwgillplumbingandheating.com/webapp/p/547/gerry's-own-house-steam-mini-tube-system



http://www.heatinghelp.com/forum-thread/131555/New-steam-mini-tube-system-installed-in-my-own-house-Iron-Fireman-style

SteamCoffee

Anything new on the "experiments?"

jumper

ttekushan,where do you locate your circulator? It needs NPSH.

gerry gill

We restored a Paul system in a house once. We used a water jet venturi for a suction source. It is a good thing the young lady likes it hot. It did work out well, however the side effect was you will heat the radiator from one end to the other. Every Time. Steve did come up with a theoretical solution tho, in using trv's turned upside down to interrupt the suction. We have not tried in practice tho.

jumper

gerry gill said:

We restored a Paul system in a house once. We used a water jet venturi for a suction source. It is a good thing the young lady likes it hot. It did work out well, however the side effect was you will heat the radiator from one end to the other. Every Time. Steve did come up with a theoretical solution tho, in using trv's turned upside down to interrupt the suction. We have not tried in practice tho.

Ideally a thermostat shuts off burner before home gets too warm. There should be no cut in if those vacuum vents hold.