This thread has been bookmarked. Visit your bookmarked threads to review.
Post a Reply to this Thread
New Geo System vs. Old Steam System System (3 Posts)
New Geo System vs. Old Steam System SystemGuys and gals, so I appreciate all the advice and thoughts on this topic so far. I'm definitely going to contact Dan. I realize getting more expertise on this topic is what we (my church) needs to make a good decision.
One thing I did do in the last week was touch base with a geo designer - not installer.
He came in and brought up two very important ideas.
1. Why not consider using ice storage?
2. In the winter, have a back up boiler.
His point matched a few of your comments. Using a hybrid system, we can capitalize on the low operating cost of geo M-F (and Saturday) by just running (lets say for the sake of argument) a 20 ton cooling system. The system would also be building up ice in a ice storage tank. Then on Sat night or early Sun morning, the system kicks in higher gear and starts using the ice storage as a quick heat sink for the peak usage on Sunday morning. We don't have evening church services. So other than weddings, we are virtually needing a AC system for just 5 hours on Sunday morning.
Likewise, he said, you could run the equivalent of a 20 ton geo system in the winter, then on Sat night (or early Sun morning) the system kicks the boiler on to preheat the water going into the geothermal heat pumps. Again, the point would be to keep the church at 55 degrees Mon thru Sat, then get it up to 68 - 70 degrees for just 5 hours on Sunday. (or the occasional Sat wedding).
I really, really like the idea of a hybrid system. Instead of installing a 40-50 ton geothermal system, we have the best of both worlds.
AND mind you ,this idea came to me from a Geothermal guy! You'd expect him to say, "go all Geothermal!" but he said upfront, this is about how to get the best bang for you buck.
Therefore, if we can cut our 40 ton quote ($350 to $400K) in half, for just $200K, then it's a much better selling point. ASSUMING this design is even possible. This was just an idea at this point.
One comment was why not keep existing steam system, but I am afraid the pipes are too old. We have an average of one leak per heating season - usually one small pin hole leak that opens up and blows steam out. And of course Murphey's law kicks in - it happens on a Sat night. As a result, I have to open up the walls and repair the pipe, repair the wall, carpet, etc. The boiler is newish, but the pipes and radiators are original, or damn near original! (The building was built in 1931. )
See pics attached for an idea of the monster we're talking about. As I said, 53 ft ceilings. LOTS of space to cool and heat.
As has been said in the other thread...(by the way -- thank you for splitting the threads!) -- get Dave on this. Usually in a steam system the only things that leak -- and they do leak, sometimes -- are wet returns. Steam pipes themselves almost never leak, nor do dry returns (note: I said "almost never"). Having pinhole leaks which blow steam suggests very strongly that you may have some failed traps, allowing steam into the returns -- and you may be running the pressure much too high.
Dave can evaluate both of these problems very quickly (and he really is one of the real top end experts), and neither should be particularly difficult or expensive to fix.
I like the idea of ice storage for the air conditioning.Jamie
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
1931 vapor system?from the radiator pictures in the other thread, it appears you may have a vapor/vacuum system [what name is on the traps-Dunham?]. these were very high quality systems for their day, and still run well, sometimes at 2 ounce down to subatmospheric pressures.
as far as age of pipes verses leaking, my pipes are from 1885 [not the oldest here], and I have had very few leaks.
I suspect that Jamie is right about failed traps, and high pressure, causing your high fuel use, which are easily put right. I suspect the boiler may have a 2 stage gas valve which would also reduce the cost of running if functioning.
post some pictures of the boiler, controls, and piping, and lets see what other suggestions we may have, to reduce your consumption by 50%..--NBC