Recommendation regarding Magnehelic sensor location and configuration

[davidmsem]

Hello all. I'm on the last steps of the install of my Pacific Energy Summit LE insert. As an insert I don't have much room to work with for instrumentation, but I do have a nice location for the temperature probe (even though I know it will register hotter as not 18" up the flue) and do have a damper in the exhaust.

I also have a magnahelic which will give me some information but not ideal and debating where to install the sensor.

I have four options from the two locations:

1) location 1 with pressure probe at some number of inches in. This will create interference with the damper so it becomes complicated. Damper may only be able to turn 90°.

2) location 1 with a flush mounted static pressure fitting.

3) location 2 with pressure probe. This would give good readings when the damper is wide open but will be meaningless when the damper is closed. But they will give me some sense of the full open draft.

4) location 2 with the flush mounted fitting. Similar issue with item 3 above. Flush mounted fitting would be easier for chimney sweeping. One less thing to take off and put back on.

As a minimum I think any of the four options will give me a decent sense of draft if the damper is fully opened. This is much more visibility than I had with my prior unit that over fired from drafting at 0.25 in of water column.

Location one has the advantage of being below the damper somewhat and will give slightly better indications of draft as the damper closes.

Any thoughts on what folks would do before I start drilling? Sure I can always plug a hole with a screw but really want to do this install correctly.

Much appreciated.

 

[EbS-P]

I think it’s just going to give a non calibrated (to the actual draft WC”) reading. Ie the numbers on the scale aren’t going to be super meaningful to others. So I don’t think it matters that much where. easier is better IMO.

 

[brenndatomu]

Option 2.

Nice setup.

 

[davidmsem]

I think it’s just going to give a non calibrated (to the actual draft WC”) reading. Ie the numbers on the scale aren’t going to be super meaningful to others. So I don’t think it matters that much where. easier is better IMO.

With the damper opened, The draft should be accurate, no pressure differential across the damper. So opened damper readings should be accurate.

Correct.?

 

[Hoytman]

In the fire box is the most accurate way to tell what is happening at the fire although it won’t be that far off from a reading in the pipe.

Several coal stove and coal furnace manufacturers actually have a location already in the loading door and some in the ash pan door.

I elected not to drill a hole into my stove or any doors and I placed my probe in the pipe just between the stove top and the pipe damper.

Easy is fine.

Edit:
My particular stove is a wood/coal stove and has a built in damper in the top of the stove. I also have a pipe damper that generally is rarely used. I placed mine between both dampers and it reads fine even when both dampers are in use. May not be ideal, but it works. Dwyer Mark II model 25.

Your situation is different, but a hope through the stove or a door would work, if that is something you wanted to do. A set screw could be put in placed when probe is not in use.

 

[begreen]

Background info

New Installation Temp and Pressure Gauge Location Questions

Hello!!! I'm working the install of my Pacific Energy LE Insert. I'm looking for help on where to place my temperature sensor, and what type. If I use a probe, it will be located only 5 to 8 inches above the unit (just above the damper, path notated). Not much room above this unit with the...

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