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Dear Reader
Dear Reader
After thirty six years of writing for industry magazines, Dan Holohan retires with his final column about what his readers have meant to him.
Re: Help draining a old steel expansion tank.
Take out the bigger plug that the drain screws into. The vent tube should come out with the bigger plug. The vent tube may be sludged up.
WMno57
1
Re: Steam heat system fitting
I’ve seen this in an old book. Can’t recall which one. It’s a specialty tee that allows the steam to go to two floors. The object was to lessen the amount of returning condensate in either riser from the tee.
Re: 4 Story 1 Pipe Steam System
Yes it's that easy...mostly...but there might be venting on that top floor to quickly let the air exit the risers and you'd have to move that venting to the third floor. And then the boiler will be instantly 25% (more) oversized or so.
But also...yikes...that's a huge change...what part of the world are you in? I will now grab my 🍿 to watch everyone freak out
I assume one of the major reasons for this is so that tenants each pay for their own heating (and they get nice cooling)
But also...yikes...that's a huge change...what part of the world are you in? I will now grab my 🍿 to watch everyone freak out
I assume one of the major reasons for this is so that tenants each pay for their own heating (and they get nice cooling)
Re: 4 Story 1 Pipe Steam System
It will work well enough. No real problem. Except... make sure that the mini-splits which you plan to install have enough electricity available to power them, and that they are able to maintain the required interior temperature at the design temperature of your area. They may struggle to do that, Or just no.t work at all...
Re: Sizing a circulator, general questions
I never left the office to look at a job without my B & G Wheel
Weil McLain WM97+110 Gas-fired water boiler not thoroughly heating
Hot water wont circulate completely around my baseboard. The pipes are only hot for about 20 to 30 feet past the Area Control Valves.
CONFUZED
1
Re: Sizing a circulator, general questions
A very handy tool, the System Syzer
Here is the EL chart from the manual version of the System Syzer.
A 5 gpm example showing the velocity and friction numbers as the chart above.
Here is the EL chart from the manual version of the System Syzer.
A 5 gpm example showing the velocity and friction numbers as the chart above.
hot_rod
1
Re: Why must The 12 psi fill pressure be increased for 3 floor house?
@Joseph_4, I'm going to post my same PM answer here for the group... and I can correct my typos
I like to think of it this way: A man shows his son how to install a boiler, he shows him that the expansion tank always goes on a certain tapping on the boilers they install. The circulator always goes on the return and the fill valve always goes on the coldest pipes in the system so as not to shock a hot boiler with cold water. He did that for 30 years and now his son has taken over the business. The father or the son never installed a boiler in a 3 or 4 story home
One day the son gets a big job and installs the boiler in the same way in a 3 story home. As soon as the job is done and the boiler operates, the relief valve starts to leak. The son installs a new relief valve only to find the same problem. He calls the father and his father has no explanation.
Well here is the answer. They have been doing it wrong for over 30 years but it never was a problem because the incorrect design was always on a 2 story home. When they needed to fill the 3 story building, the problem showed up as a leaking relief valve because they needed more than 12 psi to start with..
See if you can see the problem in this illustration I used in my classes
When all is off and cold and All the pressure gauges are at 12 PSI. Before the flame heats the water, but as soon as the circulator pump starts, the pump will drop the pressure on the inlet side because it is pumping towards the point of no pressure change... the expansion tank. But the water pressure in the return pipe will be lower than the 12 PSI of the auto fill valve. So the fill valve will add water pressure to 12 PSI. That pump will add the pump head (let's say 6 PSI) to the 12 PSI from the inlet. That is now a total of 18 PSI. With that extra water, the expansion tank gets more water in it to compress the air to 18 PSI. There is less room for expansion now. After the system cools off everything is now 18 PSI with cold water. On the next heating cycle, the expansion tank has less room so the pressure will go up to 24 PSI. Since the relief valve will not go off until the pressure gets to 30 PSI, there is no problem. The system operates at a higher pressure for years and years.
Now apply the same problem to a home with 3 stories and you need to start at 18 PSI cold. Then add the 6 PSI to that. Now on the second cold start the system will be at 23 PSI. On the second cycle... you will be getting closer to 29 PSI when the water heats up, since the expansion tank capacity is reduced. That is only one PSI away from the relief valve blowing off.
And that is the way we have done it since forever ago! Wrong but without a problem ... until there is a problem.
I hope you all followed the chain of events here... Now that make Pumping away the greatest thing since Sliced Bread!
I like to think of it this way: A man shows his son how to install a boiler, he shows him that the expansion tank always goes on a certain tapping on the boilers they install. The circulator always goes on the return and the fill valve always goes on the coldest pipes in the system so as not to shock a hot boiler with cold water. He did that for 30 years and now his son has taken over the business. The father or the son never installed a boiler in a 3 or 4 story home
One day the son gets a big job and installs the boiler in the same way in a 3 story home. As soon as the job is done and the boiler operates, the relief valve starts to leak. The son installs a new relief valve only to find the same problem. He calls the father and his father has no explanation.
Well here is the answer. They have been doing it wrong for over 30 years but it never was a problem because the incorrect design was always on a 2 story home. When they needed to fill the 3 story building, the problem showed up as a leaking relief valve because they needed more than 12 psi to start with..
See if you can see the problem in this illustration I used in my classes
When all is off and cold and All the pressure gauges are at 12 PSI. Before the flame heats the water, but as soon as the circulator pump starts, the pump will drop the pressure on the inlet side because it is pumping towards the point of no pressure change... the expansion tank. But the water pressure in the return pipe will be lower than the 12 PSI of the auto fill valve. So the fill valve will add water pressure to 12 PSI. That pump will add the pump head (let's say 6 PSI) to the 12 PSI from the inlet. That is now a total of 18 PSI. With that extra water, the expansion tank gets more water in it to compress the air to 18 PSI. There is less room for expansion now. After the system cools off everything is now 18 PSI with cold water. On the next heating cycle, the expansion tank has less room so the pressure will go up to 24 PSI. Since the relief valve will not go off until the pressure gets to 30 PSI, there is no problem. The system operates at a higher pressure for years and years.
Now apply the same problem to a home with 3 stories and you need to start at 18 PSI cold. Then add the 6 PSI to that. Now on the second cold start the system will be at 23 PSI. On the second cycle... you will be getting closer to 29 PSI when the water heats up, since the expansion tank capacity is reduced. That is only one PSI away from the relief valve blowing off.
And that is the way we have done it since forever ago! Wrong but without a problem ... until there is a problem.
I hope you all followed the chain of events here... Now that make Pumping away the greatest thing since Sliced Bread!
