NextGen Vacuum heating

izhadano

Hello,

it's been a while since I put info on vacuum heating system with naturally induced vacuum on Wall -
http://forum.heatinghelp.com/discussion/131838/vapor-heating-system-with-naturally-induced-vacuum#latest.
As usual, devil is in details and details were small leaks and failed check valves. These leaks are hard to fix if piping is buried in walls, also check valves are prone for leak as time goes by. So performance deteriorated with time and constant attention required to keep system in order took too much time ..

Turned out, that creating/maintaining vacuum by small vacuum pump in a reasonably tight steam system is much easier and consistent. In new technology, vacuum pump (~$200-400 depends on brand) is employed for 1-1.5 hr/per day so it will last for 25-30 years based on warranted 10000 hr life span. Condensate is returned by gravity, steam traps are eliminated, controls are simple and inexpensive.
Basic information on new system can be found in an article for IDEA magazine - https://drive.google.com/open?id=0B-5hKw5FhaA4RndtYjcxOWFSYWM.
These are graphs of the last 5 years monthly HDD (heating degree days) and heating bills before and after retrofit - https://drive.google.com/open?id=0B-5hKw5FhaA4c3Ntb1RiV3FMWVE.

The system can be readily utilized to eliminate steam traps problem in old-style vacuum heating systems and fix uneven heat distribution in steam systems (the less leaks the system has, the easier is the retrofit). In my case, vacuum drops from 20"Hg to 10"Hg in ~1 hr in original 100 years old system, radiators connected by old piping buried within walls. Scale is not an issue, - Empire State Building is heated by vacuum heating.

Please, let me know if you are interested to give it a try.

Best,
Igor

ttekushan_3

Let me congratulate you on a successful and sizable reduction in fuel consumption thru the use of active vacuum. The right side of the second graph really points out the difference. There's a complete reversal in the relationship in fuel use between 1st and 2nd floors-- with the first floor remaining consistent with past performance.

It's a great achievement that supports both what you have been saying and the results that I and several others here have seen with steam heating.

DanHolohan

I've watched what Igor can do for years. He is brilliant. I wish I had a big old building where he could work his magic for me.

vaporvac

He can come to my house any time he likes. Colleen

izhadano

Colleen,
thanks for invite, - what state are you? I'm in MA.

vaporvac

Southern Ohio. Drats.

izhadano

OK, I'll keep it in mind.

Steamhead

Well done, Igor!

ttekushan_3

DanHolohan said:

I've watched what Igor can do for years. He is brilliant. I wish I had a big old building where he could work his magic for me.

Ya know, you wouldn't think it should be so difficult to find a place, but it is. We're talking about the most modestly priced solution available to those with existing systems for achieving remarkably low fuel usage levels. Without or before any expensive deep energy retrofits. But thinking outside the box is a tough sell in these risk averse times even though, ironically, it is a more cost effective solution than most other options. Go figure.

I think Igor needs an agent! Heck, I need an agent.

I've had only one building owner (on a limited but "non-zero" budget) understand why restoring and modifying the original steam system to do what we needed it to do makes "dollars and sense." It was a 5 year prioritized project, since there were problems everywhere along with a dizzying array of substantial changes over the last 110 years. I haven't yet achieved anything resembling Igor's vacuum levels. Maybe this summer's repair work will get us closer. But perfectly even and swift steam distribution, expanding into steel fin tube, unit heaters and the remaining radiators, has allowed for relatively short heating cycles with even heating.

I can tell you that Igor's system will work on a large scale, if my less ambitious project is any indication. Mine isn't nearly as thorough as Igor's and yet, after 5 years, we're heating an old repurposed 175,000 square foot industrial building in NE Ohio-- with no deep energy retrofits, occupancy at 70F = 14 hours per day 6 days a week, 60F all other times-- at
7 BTU's per Square Foot per Heating Degree Day. This is nearly a 50% reduction.

Igor's system would also have an advantage in being a codified steam system reconceived all at once so the "tweaking" of the system that I'm prone to doing wouldn't be necessary. My work on this system is extensively customized to its peculiarities and building characteristics so is therefore not directly applicable en masse to other systems. Igor's is.

I can only add that Igor's elimination of steam traps puts a smile on my face. I was able to do that in areas of the building, but not throughout.

Regardless, I think the time is ripe for steam's rebirth for the future. Igor's model should make the industry rethink steam. A boiler's "efficiency" at atmospheric pressure hardly begins to paint a picture of System efficiency when we are altering all the other conditions.

Terry

P.S. My avatar is one of the two boilers powering this system.

jumper

I'm sorry that I don't have information about the vacuum heat my friend designed and installed in Toronto apartment buildings in the fifties. Cold water was plentiful so vacuum was refreshed periodically with an eductor. In one building he tried single connection terminals to save on installation costs.
Instead of pipes he used automotive tubing.CIL Canada made for him special stuff for connections.

Steamhead

Are any of these systems still running?

jumper

Steamhead said:

Are any of these systems still running?

Don't live in Toronto going on twenty-five years. I always mean to go see some boiler rooms when I visit TO but it never seems to happen.

Dave in QCA

Igor,
I find your study to be very interesting and encouraging. I too was hoping for great performance from a self-induced vacuum arrangement. I found that the most vacuum I can achieve in my system is about 5"Hg on moderately cold weather with up to 10"Hg in very cold weather. The difference, of course, is due to the increased amount of steam in the system in cold weather.

My system was installed in 1909 as a Dunham Vacuo-Vapor System. It appears that this original apparatus was removed and replaced by a vacuum pump. However, by the time we purchased the property, all vacuum apparatus had been removed and quite a number of knuckleheading had been done. My work has been to repair and restore the system to its original performance. This has been done with great reduction in fuel use, except for the last and final step of reinstalling a mechanically generated vacuum system. The empirical performance data that you have produced certainly does encourage me to proceed to that next step! Dunham Differential Vacuum is the setup I intend to re-create.

I have studied all of the vacuum system information that I could get my hands on and I find it interesting that your studies are consistent with Dunham's theories and explanation of their early vapor systems and up to their ultimate Vari-Vac system.

I have intended to write a summary of the various types of vacuum systems that were developed through the years along with the rationale and purpose for which the vacuum was being used. The fact that vacuum systems were being developed for several different distinct purposes makes it even more confusing that it would be otherwise.

I wish my system was closer to your area, but I'm sure that Davenport, IA is too far for you to consider.

jumper

I think that there's several aspects of vacuum heating.
One is that the less air the better the heat energy transfer.If all air was eliminated steam in radiator will be the same temperature as the water in the boiler.
Another is that steam circulates faster when the pressure in return piping is lower.The systems I remember accomplished this with coils exposed to colder temperatures like in building entrance or air intake to boiler room.I don't know how feasible that is for smaller building.Another way to lower that return pressure is with those combination vacuum /condensate machines.Seems to me the vent on those lets air back in.

SteamCoffee

Hi, I was wondering what vacuum pump was being used? Seems that the hang up for small systems is a pump that is matched to the systems, VariVac et al are usually for huge systems and are massive overkill for most residential steam systems. Any info on smaller pumps would greatly increase the real world knowledge, application and retrofit potential. Thanks!

izhadano

Hi, SteamCoffee:
I used AirTech piston vacuum pump - simple, oil-less and can tolerate moisture getting in (in my control set up to 35oC).
http://www.airtechusa.com/products/hp120v.html
Works trouble free for 3rd year so far.

shanericciardi

Hi Igor,
I've been a lurker here for a while as I've learned how the 2-pipe system in my own house works. I just read your fantastic article but I'm confused - how were you able to eliminate steam traps & keep steam out of the returns? Is it because the smaller diameter return lines also function as orifices? Thanks.

SDSteam

Great thread. I recently started working for a local university with a central plant vacuum system with 15 buildings connected to it. It's been hacked up and butchered for decades, the vacuum pumps haven't been used for years. Looking forward to getting it back into shape and pulling a good vacuum on it.

Great article. Good inspiration.

Also curious about the elimination of steam traps?

deadmansghost

Only old Toronto vacuum system much like described above that I have seen was last summer in the east end, and that building was empty and was to be demolished. Those systems running vapor in vacuum at approx. 170 degrees were wonderful, quiet, easily controlled.

Daniel_3

I live in MA Igor and have a 1-pipe steam system. Let me know when you want to work on it

izhadano

Hi Daniel,
when and where I can see your system?
You can contact me directly - izhadano@gmail.com

izhadano

Hi Shane,
sorry for delay - put comments twice but somehow they did not show up.
The trick is not to prevent vapor entering into return lines, but to prevent vapor entering into vac. pump. For this purpose, there is a separator before vac. pump. Temperature controller switches vacuum pump when temperature exceeds 30-35oC at the separator entrance.
Thanks,
Igor

Pumpguy

Igor,

Can you provide details of inlet separator and how it prevents vapor from entering the vacuum pump?

Thanks,

shanericciardi

Thanks Igor. Yeah I'm wondering the same thing as PumpGuy.

izhadano

Hi Pumpguy,
looks like you know the vac. pumps business better than me. There are many specialty separators on market, - expensive though. For my project I used just the cheapest available 1 gal tank (~ $110, happen to have excessively thick walls though ). Return line enter in the middle, condensate collects/flow from the botton, vac. pump connected at the top,
The idea is to slow vapor entering separator and prevent vac. pump from occasional water droplets. The temperature controller is preventing vapor entering into vac. pump based on separator entrance temperature (up to 30-35oC).
Where are you and what trying to accomplish?
Thanks,
Igor

Pumpguy

Just curious what others are doing these days?

Basic technology most suppliers are still using is from the mid 20th century. You would think something new and better would have come along since then.

You seem to be offering something new or different, so looking to learn what might be better.

jumper

Vacuum pumps have evolved. Used to be that water vapor was a problem. Needed ejectors or liquid ring or oil consuming machines. Now there are oil free dry pumps.

Vacuum generation is easy. The interesting part is how to inject condensate into boiler economically. I'm surprised how few buildings have boiler rooms deep enough for gravity to be easy. My suspicion is that pump manufacturers marketed very well.

Pumpguy

Wondering how well an oil free dry vacuum pump would work on a condensate return application? Can't help but have water or vapor carryover to vacuum pump at some point.

I am aware that Roots blower rotary lobe vacuum pumps have been used, but also know of horror stories with these as well.

jumper

Inefficient as it is you still can't beat an air powered ejector. Bullet proof and will draw down to 29" Hg. Trick is not to let air back in. If there is insufficient height to inject condensate into boiler then some serious decisions are called for.

izhadano

Actually, you don't need 29"Hg, - in my setup vac. pump run 1-1.5 hr/day to maintain 14-18"Hg in a system, but up to 25-27"Hg achieved naturally.

jumper

I didn't mean you'd run at high vacuum.But for initial purge to remove air. Many times more air at 27" than 29".