Flue Draft Gauges

[salvageV6]

Anyone know a DIY procedure to measure flue draft in a oil fired hot water heating system?

Need to measure the water column measurements as outlined below.

And so far the cheapest I've seen is the Bachrach hand held for about $100.

A one time use DIY scheme would be nice or some science project apparatus I could build, have lots of stuff available just not this specific meter.

Any help would be appreciated.

" In sum the draft we typically see on oil fired heating equipment is

- 0.02" to 0.03" water column (w.c.) in the combustion chamber just over the fire
- 0.04" to 0.06" w.c. in the breech - the flue pipe area between the top of the boiler and the bottom of the barometric damper. Some oil burner models require higher draft than these numbers, and other oil burner models are actually tolerant of back-pressure in the combustion chamber (positive draft, or draft in the "wrong" direction"). "

 

[salvageV6]

Thought so.

TTT

 

[BandAid]

just get a mag gauge..

Dwyer Magnahelic 2020-ASF 0-20" WC Pressure Gauge NIB - eBay (item 130260109964 end time Nov-01-08 18:36:01 PDT)

 

[101prf]

A magnahelic like above would be what you need if you can find it in the range you need at that price! Some u-tube manometers have a low range you use by laying them sideways but is difficult to read that low.

 

[101prf]

DWYER 2002 MAGNAHELIC GUAGE WITH STAND - eBay (item 200259973801 end time Oct-10-08 12:22:28 PDT)

This one has the range you need.

 

[salvageV6]

I made one from a U shaped tube with water in it.

Unfortunately the range of movement of the water is 1/32" which isn't easy to see. Didn't get any movement at all from an 8" stack with the flue flapper closed.

The first one listed needs 20X more greater accuracy for my measurement.

That Dwyer might work.

Missed a draft rite Bacharach for $30 by a week.

 

[101prf]

I've used the dwyer before when the electronic combustion analyzer was broke, i had to pull out the old timers chemistry set!

 

[Top Speed]

Any measurement in the hundreds of an inch of water column will be very difficult with a homemade instrument. I recommend a Dwyer Series 475 Mark III Digital Manometer for that application.

 

[salvageV6]

Yeah the homemade one doesn't have the resolution needed either.

Would work fine for gas flow however. 6-7 inches is easy to measure.

Anyway I'm thinking that used Dwyer meter on ebay has good enough resolution and should be reasonably priced.... I hope....

We can easily make a pitot tube for it.