Those useful tidbits of information

[Gooserider]

One of the things I've noticed over my time in the Boiler Room is that mixed in with all the various questions and discussion that apply to the particular issue are occasional "nuggets" of really useful information, such as products that do a really exceptional job, or have other features that make them different from just the generic versions that other companies make, tips and techniques that we can all benefit from, and so forth... These are great, but with all the volume of traffic we have, they tend to get buried in all the other messages and either not seen, or just hard to find later - "I know I saw something about .... that was really good, now where was it?"

I am starting this thread in an effort to save these useful tidbits for future reference, hopefully you will find it useful. In order to keep it visible and high quality, I'm making it a sticky, and closing it to all but Mods - What I'm hoping to do is paste in bits of interesting threads, with a link back to the original if anyone wants the context. Hopefully the Mod Squad will catch stuff that belongs here and add it as we go along, you can help by pointing stuff out that you'd like to propose for addition either by PM'ing us, or suggesting it in the threads themselves...

I also want this to be for those "extra-special" items - not stuff where there are lots of vendors, and the choice is largely one of opinion - so I WON'T be putting boilers in for example. OTOH, we have several pros that know about products that the rest of us might not find out about unless we spent way to much of our time buried in the product catalogs and such...

So to start off....

In this thread the subject came up about low head resistance flow check valves, and NoFossil was mentioning a desire for gasketted union style fittings -"in hot water" had some answers. See posts 42 & 43 especially.

Watts and Combraco still offer inline, low pressure drop spring check valves.

Anytime you run piping vertically from a boiler or piping loop you really need a check on both supply and return side. Hot water can actually go up a return pipe and overheat a zone.

Same with an indirect water heater, without check protection on both supply and return they tend to over-heat just from hot to cold convection movement. Some old timers still use a pump AND a zone valve when piping indirects to assure a 100% shut off of flow.i

B&G;offers iso flange valves with that same check built in. It does move the check an inch or so away from the discharge.

Really discharge side is not a bad place for a check, you never want ANY flow restricting device on the inlet side of a circ, too much potential for flow restriction to start cavitation.

hr
Image Attachments (a couple of spec sheets)

Flanged gasketed fittings are very common in Europe and we are seeing more of it over here, especially in the solar industry.

The company I work for, Caleffi, manufacturers thousands of brass flanged fittings. If you need something special let me know.

But the real key to the excellent seal on those flanged fittings is that green gasket. Once some fluid hits them they swell and glue to the surfaces. When you disassemble one you end up scrapping the gasket from the fitting faces. Often times hand tight is enough with those gaskets.
<snip>
hr

In this thread, around post #20 I was grumbling about the way zone valves want power to hold them in their actuated (open or closed depending on the valve) position -

Gooserider - 27 August 2009 03:04 PM

What I’m kind of surprised is that nobody seems to have a zone valve design that only draws power when changing state… i.e. motor to open, then turns off with the valve staying open until it gets a signal to close, at which points it motors to close, and turns off until it gets a signal to open, etc. It doesn’t seem to me that it would be any harder / more expensive to build than the current style which seems to require constant power to maintain it’s active state, and does a spring loaded reversal if it looses power…

Gooserider

NoFossil responded:

The (broken link removed to http://www.taco-hvac.com/en/products/Electronic+Ball+Valve+EBV+Zone+Valve/products.html?current_category=69) does exactly what you suggest. The problem with zone valves is that the signal to close is the removal of power. With no power, how do you close the valve? Hence the spring. The Taco EBV stores enough power to close the valve after power is removed. It consumes essentially NO power, open or closed. I love them.

 

[Gooserider]

Snake Oil - or Easier creosote removal...
https://www.hearth.com/talk/threads/41704/
willworkforwood Posted: 19 September 2009 10:17 PM

I’ve been having a big struggle with creasote in my boiler heat tubes. But, this was a self-inflicted wound - I knowingly used poorly seasoned wood, trying to make it through the Spring. My bad . Had I known what what happening in the tubes, the boiler would have been shut down at the beginning of March. But, unfortunately it’s not as easy with an Econoburn to get at the tubes as some others - the top and back plates have to come off in order to pull the turbs to get a look at the tubes,. And, the turb lever was working fine, and the boiler was heating well so I didn’t suspect that creosote was forming on the tubes. Pilot error.
Anyway, I’ve been trying a bunch of stuff, with no luck - this creosote would make great epoxy. Piker sent along what looks like a very effective grinding method developed by Gary Barker, but I’ve got a bit of elbow tendinitis right now, and can’t handle the torque from the heavy-duty grinding. Lighter grinding using cut off washers works, but is REALLY slow. So yesterday I was poking around for other possibilities on the web, and came upon “how to remove creosote”.
It said, just mix wood ash with water, apply to the creosote, and brush or scrape off. Snake Oil, I said to myself. But, I filed it away - try it tomorrow and have a laugh. This evening I mixed up some of the Snake Oil, and applied it to the ledge of the top chamber. I waited a minute or so, scrubbed lightly with a wire brush, and then wiped with a rag. A quick Holy #@%! popped out when I saw the patches of bare metal (with very little effort). Then I applied some to the top section of an uncleaned tube, and spun a wire brush on a drill (the same wire brush that the creosote was laughing at last week). Voila! - it was coming off . Early next week I’ll work out a delivery method to get the Snake Oil to the work area, (probably just loading a pile onto the back of the wire brush will work), and I’m fairly confident that this will finally get the job done.
I wanted to share this information with others - I know that Reflex1957 was having this same problem, and I would guess there are others as well. I also wanted to post the url of the web page that I found this on as a thank you, but can’t find the site - my web history gets cleared daily - I’ll keep looking.

 

[Gooserider]

Useful manufacturer reference links - obviously these links try to promote their various manufacturer's products, which isn't necessarily a bad thing, but they can also be used as a good source for information on system planning and what kinds of components to look for, regardless of what brands you end up using - for instance the Taco paper on selecting circulators describes a method that is just as good for choosing a Grundfos circ as one of Taco's..

(broken link removed to http://www.taco-hvac.com/uploads/FileLibrary/SelectingCirculators.pdf) An excellent paper with the basic formulas and guids needed to pick a circulator, and indirectly some good thoughts on sizing piping for the entire system.

http://www.caleffi.us/caleffi/en_US/Site/Technical_library/Idraulica_magazine/index.sdo Caleffi has an ongoing series of papers called "Idraulica Magazine" that serve as good primer pages with a lot of useful layout diagrams for different sorts of systems. This link is to the index of the various issues, each of which has a great deal of good content on the specified topic.

 

[Gooserider]

A couple of useful websites that I use alot, both when doing stuff here, and in a lot of other contexts...

The units converter that I use is convert-me.com They have the site setup to convert just about any unit to any other if it can be done, with a very nice interface - they give you a list of units, fill in the value for what you have and it gives you the equivalent in the others... The only challenge sometimes is to find the right page to start with, but they have a good search function for that as well.

Another useful website that is sort of an on-line equivalent to those old pocket reference books is The Engineering Tool Box They have a lot of charts of values for different kinds of things, including conversion factors, but not as nice of an interface.

 

[Gooserider]

Advice on how to power clean boiler tubes.

I think it was Barnartist that asked about a cleaning brush to really clean the boiler tubes. I went to the hardware store this morning and came up with this. Items: one 36” steel rod, one cable tie, and a 2 inch wire brush that fits on the end of a drill. I hooked them all together and it work really, really well. I thought I had cleaned the tubes pretty well before, but this takes everything off down to the metal. The only problem I had was that I hadn’t cleaned for quite a while and the tubes were pretty bad. The brush would heat up and the creosote would coat the wires. I just let it cool a minute and then beat on the brushes to chip it all off. Someone that has a shop should come up with something like this with set screws so you wouldn’t have the cable clamp. Could make some money. I have a total of under $7.00 into this (not including the drill!!).
Image Attachments

To see pictures, go to the original thread

 

[Gooserider]

A useful link for calculating the size needed for expansion tanks. B2E Expansion tank calculator They also do a couple of other items that look like they might be of use for some applications, but not to much for our purposes.

This thread on Storage questions particularly around page 3 has some interesting discussions about alternative expansion tank options, including a potentially quite useful Bell & Gossett fitting for using non-bladder tanks.

Gooserider

 

[Gooserider]

(from this thread , see the top of the second page)
A brilliant product link from Heaterman - I was commenting that I hadn't seen anybody doing a pre-manufactured version of closely spaced tees, and he came up with one, with the brilliant idea of adding a ball valve in the middle to make flushing easier...

Gooserider - 27 October 2009 10:55 PM
From the hardware standpoint - to do closely spaced tees most effectively, put them together using a “close nipple” on black iron. On Copper, a section of tube that only lets you see about 1/8” of pipe between the two fittings. On PEX the shortest length that will let you assemble the two clamps…

IOW, while the MAXIMUM is no more than 4x pipe diameter, the optimum distance is as close as you can mechanically get the fittings… Keep in mind that you are looking at a mechanical minimum of about 2 pipe diameters just from the length of the tee bodies, and you really don’t want to add anything to that.

(I’m mildly surprised that the fitting makers don’t offer a pre-manufactured “close spaced tee” as an actual fitting - or maybe they do and I’ve just never seen it mentioned)

Gooserider

I use and sell a ton of these. The ball valve in the middle makes it possible to purge the secondary loop through the same ports used for the primary. Webstone rocks

(broken link removed to http://www.webstonevalvespurgetee.blogspot.com/)

Dogwood pointed out that Taco makes a different product that is based on sort of the same idea -

Taco “Twin Tees” serve the same closely spaced tee function as the Webstone fitting, without the ball valve advantage however. Try (broken link removed to http://www.taco-hvac.com/uploads/FileLibrary/100-6.8.pdf).

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Suggested by SDRobertson, another comment by Heaterman, on just how bad you hurt your performance when you try to burn green wood in an OWB... (from post #11 in this thread

Looking at it another way…...let’s assume that you use the unseasoned wood in a typical outdoor wood burner that runs about 40% efficient itself (real world number not factory hype)

A: Starting with 100% of the heat stored in the wood or 10,500 btu’s deduct the 4000 wasted by evaporating the moisture and you have 6000 btu’s available for heat transfer to the water. An average efficiency number for any OWB is about 35-40% so multiplying that 6000 btu’s remaining by 40% leaves you with 2,400 btu’s available to heat your house. That equates to a LOT of wood burned over the course of the winter.

B: Now if you start with seasoned wood, say 20% moisture content, you’ll have about 8,000 btu’s in the firebox. If you burn it in a modern design gasifying boiler your combustion efficiency is an honest 80% which leaves you with 6,400 btus instead of 2,400 in the first scenario.

Can you envision hauling cutting splitting stacking and loading 3 times as much wood in scenario A vs scenario B? Not saying you should look a gift horse in the mouth and turn down the OWB your dad is giving you ...........just trying to prepare you for what you’re getting yourself into.

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Found by MrEd in this thread, a nice basic tutorial on relays:http://www.bcae1.com/relays.htm It is mostly intended for car audio applications, but the basic concepts apply to any relay application.

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When laying out plumbing, one of the things that must be considered is the Cv or "flow coefficient" of any valves and other fittings - This is essentially a measure of the restriction that the valve will impose on fluids passing through it. It is important that one not put a valve in a pipe that offers an excessive restriction to the fluid passing through it. From Steve Gschwend;

Cv – Flow Coefficient = Index of Flow Capacity equivalent to the gallons per minute of water at standard temperature (60°F = 16°C) which will flow through a valve or fitting at a pressure differential across the valve of 1 psi. (the assumption is that a 1psi drop across the valve is not significant, therefore the Cv indicates the acceptable flow rate for the valve or fitting).

This thread has links to some useful references with the equations and values for some common valves, and an on-line Cv calculator.

Gooserider

 

[Gooserider]

Thread on building sidearm exchangers probably could use some additional links.

Discussion on boiler ratings. Bottom line, the ratings don't have a lot to do with the real world, but are useful for comparing similar size boilers. It seems to work best to assume real world output will actually only be about 75% of rated value. Since the output will vary as the fire goes through it's natural cycle, this also makes storage important if one wants a steady temperature in the home.

Propane 101 website for propane customers, lots of emphasis on getting stuff done by "Licensed Professionals" but has some useful info on propane tank sizing and such that might be of use to those building storage systems.

 

[Gooserider]

We usually tell our newcomers to figure their heat loads as one of the first and most critical steps in planning an installation. Refined Home Renovations offers this (broken link removed) on their website. They also have a few other interesting tables and such in the references section of their website. There are fancier heat load calculators, but this will at least get you started, though is somewhat limited.

A thread with some good info on the care, feeding, and especially cleaning of flat plate heat exchangers One of the problems with this type of exchanger is that it tends to trap debris, and build up deposits from the water passing through it, which can reduce it's efficiency, and eventually prevent it from working all together. This thread looks at some options for preventing problems, including how to plumb the HX to make it easy to clean...

Gooserider

 

[webbie]

Here is an amazing thread on start to finish Gasification boiler installation with storage:
https://www.hearth.com/talk/threads/32524/

 

[Gooserider]

There have been occasional discussions of draft and how to measure it... You can get high precision, expensive instruments to measure it, but if one is careful it can also be done for a couple dollars with a home made setup...

Here are some instructions I posted in another thread -

One can do a home brew draft gage with a bit of ingenuity and a bunch of clear fish tank tubing. You will need a container that the tubing can attach to on the bottom, and is open at the top, plus a moderately good sized board - say a 1x10” or 12”, 2-3’ long.

Attach the bottle to one end of the board, and run the tubing up the board in a straight line, on a diagonal, that starts on the end with the bottle about 2-3” up on the board and is an inch or two higher on the other end. Position the bottle and the start of the tube so that you can put a few ounces of water in the bottle before the level is even with or a little above the start of the diagonal. Continue the tube from the high side of the diagonal long enough to connect to the flue.

Mark a zero point near the low end of the diagonal, and then mark very accurately the height of the tube above a line drawn the length of the board through the zero point every 1/2” or so along the tube.

Make a hole or fitting you can attach the tube to in the flue - and some way of connecting the tube that will be low enough temp not to melt it.

Position the board near the boiler with the line through the zero point being dead level.

With the tube NOT attached to the flue, carefully fill the bottle with water until the level in the tube is EXACTLY at the zero point. If you have trouble seeing the water level, try adding a drop or two of food coloring.

Hook the tube to the flue adapter. The draft will pull the water up vertically an amount equal to the negative pressure - this is where the “Inches of water column” term comes from! Since the tube is at an angle, the water will also travel horizontally, in effect spreading out the vertical distance so you can see just how far it went up… Usually you want to see what the reading is with the boiler going full blast, and set your Baro accordingly.

Note that this is a home brew version of a precision instrument - the quality and accuracy of your readings will only be as good as the job you do in construction, and the care with which you use it…

Since I’m not sure just how clear my description above is, I just drew a rough plan for one in QCAD and attaching a JPG of my drawing. The dimensions are not critical, I just included them to give an idea of how it works. Also I accidentally set the scale wrong when setting up the drawing, the green measurements are off by 10, so shift the decimal over one place… On some pro-models of the same idea, I’ve seen them do a sort of “hockey stick” curve on the angled tube, where the angle gets steeper as the amount of suction goes up, on the theory that you don’t need as precise a reading. OTOH, if this doesn’t give a precise enough reading, making the tube angle lower will spread the scale out further, with the limit that the lower the angle, the more precisely you will need to make sure the reference line is exactly level. I can’t emphasize enough how critical it is to get the level right, especially as the vacuum level being measured gets smaller…

Rather than using a construction level, one can arguably get a more precise leveling action by running a second length of tube in a wide “U” from one end of the board to the other, and filling it part way with water - then measuring the distance of the two water column ends from the zero line (or a second line parallel to it) - if they are the same then the line is level…

 

[Gooserider]

Good discussion of why one should use a Barometric Damper on many installs, and why it needs to be set properly, with appropriate measuring instruments https://www.hearth.com/talk/threads/29691/

One of our members, WoodNotOil, has started a database for boilers, and dealers / distributors / installers at http://www.WoodNotOil.com It is still in the early stages of development, but it looks promising.

A very long thread on Data Logging and control circuits can be found on this thread
https://www.hearth.com/talk/threads/48079/ - it is a lot easier to fine tune a system to get the absolute best possible performance out of it if you know just what it's doing... It can also be a good early warning system for problems or alerting you to needed maintenance tasks. This thread explores a great many different options for different approaches to doing data monitoring and logging, mostly computer related.

Hansson, one of our EU members, found this set of hydronic diagrams (broken link removed to http://www.effecta.se/images/hydraulicschemes.pdf) published by Effecta to use with their equipment. These have a definite tendency to use some proprietary stuff, especially an EU styled multiport storage tank with a bunch of indirect coils, but could be used as inspiration for other designs - they are also very heavy on solar panels...

A somewhat technical discussion about the physical properties of PEX tubing, and how suited it is to use in hydronics systems - lots of links to technical tables and the like seems to confirm that it shouldn't be a problem under normal conditions, but one should avoid over heating it - which is just what the manufacturers tell us... https://www.hearth.com/talk/threads/48698/

One challenge in designing storage tanks is trying to maintain good levels of stratification, especially as one circulates water in and out of the tank. One approach is to use diffusers at the inlets so as to slow the flow and minimize the mixing effects of water entering the tank. This thread https://www.hearth.com/talk/threads/49119/ contains one design for a diffuser, and links to some VERY technical papers on the topic...

An issue with PEX is how to connect it to other hardware, or even to other PEX tubing - there are many different connection systems, and fitting types each with its own tooling, and types of PEX that it will work with - here are a couple of threads that discuss the options... https://www.hearth.com/talk/threads/36799/, https://www.hearth.com/talk/threads/47621/

A somewhat inconclusive thread about the different sorts of PEX - good data, but it isn't real clear about what kind is better... https://www.hearth.com/talk/threads/22799/

Some users have older houses with "gravity" based systems in them - this is a nice thread discussing some of the nuances of putting a wood boiler into a gravity setup, also has a link to a nice article on how the gravity setups work in general. https://www.hearth.com/talk/threads/46483/

 

[Gooserider]

Sometimes there is a need to replace refractory bits in a boiler, which might be either unobtainable, or overly expensive... This link http://www.gordosoft.com/woodstove/refractoryDIY.htm is a "HowTo" on at least one way of making them, written by one of our Hearth Room participants... It was written for stove parts, but I see no reason the same approach couldn't be used on a boiler.

Gooserider