Best Of
Re: Slant/fin vsl-160 thermal insulator changeout?
The manual, at least the Peerless PC160 version I looked at has an exploded diagram and parts list, maybe that will help. Can you get the part ? No replacement part, I would not worry about taking it apart.
109A_5
Re: HTP Munchkin 926 0-10v control
I have that board, just purchased it for my project doing the same thing. Board had four resistors, two caps, and one transistor of some sort. The instructions say the unit can also be used for something called Boiler boosting. Six wires come out of the box. Two wires get plugged into empty slots on the boiler controller Molex connector. Two wires can be used for 0-10V boiler control or two wires for boiler boosting. I plan to use this board to get my Tekmar 403 controller communicating to my Munchkin via 0-10V tomorrow. Will almost be as good as my old Vision2 system that died earlier this year when done, I hope!
Re: Efficiency of an indirect water heater
I started this post for those looking to maximize the efficiency of dhw production
Specifically those with mod cons, solar or heat pumps looking to use the lowest possible temperatures. Although it applies to any and all heat sources
To that point a heat exchanger with two forced flows beats a coil or a tank in a pool of still water, ie a typical indirect, by a large margin in fact.
Idronics 29 explains the theory, application, sizing examples pretty pictures and more
Pretty simple basic observation. Food for thought for thought for those willing to learn. Which is most of the HH membership😀
Or as my heat transfer guru explains it
hot_rod
Re: Air in second floor loop
@jesmed1 may have the answer. If you are trying to push air down a vertical pipe you need some velocity. If the water flowing down the pipe is not flowing fast enough, then it will be like a water fall, just pouring over the edge of the top elbow, and allowing the air to float back up to the top. If however you force the water down the vertical pipe with some velocity then the air will be pushed along with the water and be forced out the open purge valve.
There is an ideal way to pipe a system to purge air and get the greatest amount of velocity without worrying about the relief valve popping open. I will explain it to you the way I learned about from The Great Dan Holohan God of Hydronics. (only using @doublekay term from above)
I used to teach this in my one day Hydronics seminar for EH-CC.org
Off Topic: Who is Alpha❤️? and why isn't it hanging up in a Mancave somewhere?
Re: Air in second floor loop
OK I have had your situation many times. You may need to build up pressure in the expansion tank by closing the valve to the garden hose valve, until you get to about 26 PSI on the gauge then open the valve and let the water push as much air out as it can until the water pressure drops to 10 or 12 or what ever. then build up the pressure again by closing off the garden hose until the boiler gets to 26 PSI. then open the garden hose again and let that force push more air out. You may need to do this 5 or more times or until you done get any air. Each time you will get a little more air to purge. Once you no longer get air, that that top floor loop is air free.
Re: Air in second floor loop
and yes make sure your makeup water valve is operating properly to maintain pressure whilst purging. It would be great to have a bypass for that but definitely not necessary. Also, besides the temp/pressure gauge on the boiler it would be great to have a way to verify pressure. I have a reliable gauge I can screw onto the boiler drain hose threads to field verify pressure. The one on your boiler may or may not be accurate.
Re: Air in second floor loop
did you put the fill valve in fast fill mode, by lifting the lever?
Also the backflow probably has a screen on the inlet, they plug easily and will limit your fill valve flow
hot_rod
Re: How cool is too cool for condensate return temperatures? How do you choose?
Calculating the condensate volume is really simple. What you need is the EDR of the radiator to start. Then the radiator output is 240 BTUh per square foot EDR — so multiply to get the BTUh of the radiator. Then that heat (and it is a refrigerant problem — it's just that the refrigerant in this case is water!) is provided by condensing the steam — at the rate of about 1,000 BTU per pound of water or steam. Close enough anyway (it's actually 970). So a bit of math and you have pounds of water per hour, then get that down to gallons per hour then down to gallons per minute.
And it is astonishingly small. Actually that's one of the beauties of steam — you don't have to handle much water.
On the leaking of steam into the returns. There are really only two ways to do that — one is to limit the steam entering the radiator to what it can condense, and the other is with a trap. In the old days, with vapour systems with very tightly controlled pressure, the former was common — either with orifices or with special steam valves (which are still made) which have what amounts to a variable orifice which can be adjusted to limit the steam, but still allow the radiator to be turned down or off. Expensive. More important, either of those requires that the pressure be maintained in a rather limited band, as both are sensitive to pressure differential. A much more reliable way is to use a trap on the outlet…
Now since you are running two pipe steam, balancing demand is really simple, since on two pipe you can control the heat from the radiator simply by partly closing the inlet valve (unlike one pipe, where you can't do that). So, for your elderly lady and the rest of the house, get it all going so she's nice and comfortable — might even put the thermostat in her area if you can keep her from fiddling with it — and then throttle the rest of the radiators to get the results you want.
Later on if the budget permits (or you find that you want them) you can put TRVs on the radiators — just remember that they can reduce the heat, but not increase it.
Re: Boiler not reaching desired heat levels
good point, it might help to know if this is a specific complaint from unit, and what the temp actually is in that unit. Possibly new tenants? possibly a window not shut tightly that used to be shut? anything at all that changes in the spaces that are not controlled by their own thermostat will change the temperature in that space over similar outdoor conditions from previous years
GGross