Manometer Arrived, Some ??

Lightning wrote: Just some food for thought. By having the mano probe after the MPD, you don't get an actual reading of what pressure the stove is feeling which is the reading that's most desirable. That's if you close the MPD to control your draft..

True. I treat the MPD as an integral part of the stove, though. My mano tap was intended to set the baro properly and to monitor the chimney draft. I've considered adding a second tap before the MPD, but to date I haven't really felt the need.

brunom15 wrote:

Lightning wrote: Just some food for thought. By having the mano probe after the MPD, you don't get an actual reading of what pressure the stove is feeling which is the reading that's most desirable. That's if you close the MPD to control your draft..

True. I treat the MPD as an integral part of the stove, though. My mano tap was intended to set the baro properly and to monitor the chimney draft. I've considered adding a second tap before the MPD, but to date I haven't really felt the need.

I did the same thing kinda', I installed the mpd months after the mano when I saw the baro needed help. Well I wanted the mpd near the stove and the mano was a foot and a half away so...I too consider the mpd part of the stove and my draft is .03 And plus when I want to see if the mano is working I just exercise the mpd.

joeq wrote:

ddahlgren wrote:Copper tubing is not legal for use on brake tubing!!!
If you use it and it fails you are liable. If you do it for someone else even for free as well as successive owners of the car. Brake lines need a double flair with the proper tools or just don't do them.

Yeah, yeah, yeah, you're right DD. That's why I put a question mark next to it. Any auto parts store has "soft" brake lines, and I'm not sure what it's made of. It cost a bit more, and comes in a roll, and you're right about double flares. But today they even modified that, and incorporate a "bubble" flair, which is basically 1/2 of a double flair. But for a manometer, you could even use copper tube. Mine is 1/4" copper tho, and not 1/8th.

Your both right,... sorta !

This is DOT certified copper brake line that we use in the pre war cars. And many high-end new European cars use it such as Volvo.
http://www.summitracing.com/search?SortBy=BestKey ... ake%20line
http://www.cunifer.com/

Not sure you'd want to spend the money on it for a stove, but if you ever have a whopper of a puff back, it'll be the last part of the stove to explode !

Paul

By hooking up the mano nearer the stove and before the MPD, you can better see the stove damper's and MPD's settings affect on the stove draft to get the best adjustments of those dampers.

If it's hooked up after the MPD and you open the MPD to see what the stove draft is,...... you just changed that.

Paul

Isn't there a thread on this topic? I remember reading about it here, and did as suggested by hooking the mano up between the stove and the MPD as Paul pointed out. Some of the stove manufactures recommend a specific draft setting for the stoves performance, and if there's some kind of restriction before the mano, you won't really know what the stove is seeing. Makes sense to me.

Sunny Boy wrote:By hooking up the mano nearer the stove and before the MPD, you can better see the stove damper's and MPD's settings affect on the stove draft to get the best adjustments of those dampers.

Again, quite true, and why I've considered adding a second tap before the MPD. I am curious to see what the pressure differential on the other side of the MPD is under various operating conditions/settings, but it's not a priority. Then I suppose I could add another tap before the direct/indirect (baseburner) flap in the back pipe, to see what the draft is upstream of that. And perhaps a fourth tap below the grates as well, so I can directly measure the effect of the primary intake dampers. With all those measuring points, plus a slew of thermocouples interspersed throughout the system I could fine tune each control to it's optimum setting!

I chose to put the tap before the baro because I wanted to measure the draft at that point, treating everything upstream as "stove", and everything downstream as "chimney". To each his own.

I tried that,...... somewhat.

Since I had a second mano waiting to finish the GW #6 I plumbed it into the range cook top surface - into the indirect flue before the stove collar and compared the readings for a week . Readings were only .01 higher inside the range when in indirect (base heater/oven) mode.

Opening the check damper slowed the range and lowered the stove mano reading within .005 of the stack reading. Even with the mano open 50% - more than I ever use- the stack mano reading stayed the same and the stove reading got down to even with it.

In direct mode - during reloading they switched - the stack reading slowly became the higher reading. As the chimney got hotter and the draft stronger, chimney draft reading would get as much as .02 higher than inside the range. Even though the stove collar area that the direct/indirect damper opens into, that area never closes off to the indirect flue where the stove mano was reading. The damper just opens and closes a short-cut directly from the firebox to the stove collar.

Since the direct/indirect damper is only a few inches from the end of the firebox, and often the flames are drawn through the damper when in direct mode, I didn't try plumbing the mano before that damper.

Paul

Very Interesting! I would have expected the chimney draft to always be higher than draft anywhere upstream. Clearly there are more complex physics at play.

One question: Did you zero and swap both manometers during your tests, to average out any instrumentation variability?

Both gauges were checked for level and zero before and after. Checking by temporarily swapping both probes into the pipe showed no discernible difference in readings, so all readings were done as you see setup in the first picture.

Not sure why, but I expected to see a greater difference in readings. And there might be with other designs of stove where a stove reading can be taken right upstream of the direct/indirect baffle, instead of downstream but still inside the stove, like I had to.

This test was a result of some discussion about check damper use and concern about it lowering the draft too much. My range has about double the square area of check damper opening as the Glenwood pipe dampers, but at 20 pounds, less than half the firebox capacity of most heating stoves. I mostly wanted to see what affect various amounts of check damper opening had on either reading. So, I chose to locate the stove probe upstream of the check damper.

While opening the check damper would slow the stove, as it's designed to do, and thus eventually lowered the pipe readings, what surprised me most was that it had more affect on the stove readings than it did on the pipe readings. The stove readings never got less than the pipe readings. Only at most, matching the pipe readings at check damper openings greater than I've ever needed to use. So, within the range of 25% to 10% check damper openings I use, the stove always has more draft.

The manometer has been wonderful for showing me things about how well the range works under various conditions that I never was able to see without it. IAs such, 've gained new respect for the designers. They really had it figured out very well 112 years ago.

The other plus of the mano is it has taught me alot about how to better operate the range, with it's six dampers and many areas to be heated at different times.

Paul

My manometer take off is pretty close to the stove but I don't have a lot of room to play around with.
I've since replaced the 6" baro with a 7" so the MPD stays wide open as it's no longer needed when the baro is installed. For cool Spring/Fall burning the baro whole gets capped the MPD comes back into play.

Hey, that looks a lot like my set-up.

Update.......sort of. Smallest brake pipe at NAPA was 3/16". I can live with it. Going to make a hole slightly under the O.D. size of the threaded fitting supplied on the brake pipe and screw it into stove pipe. I have a tiny wire clamp I will fasten to the brake pipe on the outside of the fitting to maintain desired depth. I reduced the O.D of the brakepipe for about an inch on the end down to .150 O.D. to fit onto the hose supplied with the mano on my pedestal grinder, polished ground area with 220 emery cloth, applied some silicon spray to it and it slipped nicely into the mano tubing. Now, I'm a little confused on where to place this mano? Chimney side or stove side, I have read both positions, some are using two manos . It seems to me no matter where it goes the damper is going to affect the reading. I have a Baro on the DS Machine in the basement and that's the stove I want to install it on. I think I would like to put it on the chimney side of the damper. What say you??

stove side of the baro.

you are operating the stove, not the chimney.

you want to be able to see the level of neg. pressure the stove and fire are responding to.

what the chimney is doing past the Baro. is the Baro.'s responsibility. besides you have to have the mano. tap on the stove side of the Baro. to set the Baro. accurately.

get your flame suit on, i'm sure there is a napalm attack about to launch.

deepwoods wrote:Update.......sort of. Smallest brake pipe at NAPA was 3/16". I can live with it. Going to make a hole slightly under the O.D. size of the threaded fitting supplied on the brake pipe and screw it into stove pipe. I have a tiny wire clamp I will fasten to the brake pipe on the outside of the fitting to maintain desired depth. I reduced the O.D of the brakepipe for about an inch on the end down to .150 O.D. to fit onto the hose supplied with the mano on my pedestal grinder, polished ground area with 220 emery cloth, applied some silicon spray to it and it slipped nicely into the mano tubing. Now, I'm a little confused on where to place this mano? Chimney side or stove side, I have read both positions, some are using two manos . It seems to me no matter where it goes the damper is going to affect the reading. I have a Baro on the DS Machine in the basement and that's the stove I want to install it on. I think I would like to put it on the chimney side of the damper. What say you??

If you install the mano chimney side you're reading what the baro is letting in, by installing the mano stove side you're reading what the stove is letting out!

X3 on the stove side, as mentioned above, and many other places on this site. You could put it anywhere you want on the pipe, even at the top of the chimney, and it would probably read. But if your looking for accuracy, the stove side, before the MPD, and the baro.
(IN-COMING!!!! )