Here’s the final installment of our quick lowdown on what HVAC test instruments you do and don’t need along with what features they do and don’t need to have. (If you missed them, check out Part 1 and Part 2.)

The third item on our list is a Manometer.  It can be electronic, mechanical, or fluid style.  Typically this instrument would not see the abuse from daily use that your other instruments will, so it doesn’t need to be as robust. I say “typically” because depending on the type you choose, you may be able to use it for air flow measurements and gas burner pressure measurements.  If it will be doing double duty I recommend one that has a robust casing that can take the rigors of daily use in the winter time. A manometer used for double duty should be an electronic style that can measure positive and negative pressures.  For those who prefer dedicated instruments (me) I recommend a mechanical (gauge style) for gas pressure, and a liquid incline style for measuring air pressure. Again, both should be able to measure positive and negative pressures.

Features you need

  • ¼” barb hose fittings
  • Flexible tubing not affected by temperature extremes
  • Scale ranges-2″WC to + 20″WC for double duty electronic. -2″WC to +2″WC for air duty. -1″WC to +20″WC for gas duty.
  • Must be unaffected by the temperatures they will be used in. Note that some electronic manometers are only rated down to 32 degrees Fahrenheit.

Fourth on our list is a combustion analyzer. Yeah, I know, this is a big financial nut to swallow. All the more reason for your employer to supply one for you. If you company won’t supply one, you will be spending between $500 and $1,200 depending on how fancy you get. If you’re footing the bill, don’t get fancy. Pay for features, warranty, and calibration cost, but leave the unnecessary crap behind; no thermal printer, no fancy smoke tester (buy the cheapest one you can find, it’s only a smoke tester).

Here are the features you need

  • O2, (Oxygen)
  • CO (Carbon Monoxide)
  • CO2 (Carbon Dioxide)
  • Smoke tester (if you don’t already have one)
  • Temperature
  • Excess air
  • Efficiency
  • Nitric Oxide (this will likely become mandatory soon, make sure the sensor can be added in the future if it doesn’t already have it)

Very useful, but not needed features:

  • Draft
  • Static pressure

When making the decision on what brand and model to buy, remember that this instrument may take of a gas pressure manometer, a static pressure manometer, and a temperature probe if it’s equipped with features. If you haven’t bought the other tools yet, it may be cheaper to buy an analyzer with the functions built in rather than to buy three different instruments.

Some good brands to research are Fluke, UEi, Testo, Cooper, and Bacharach just to name a few.

Remember to compare features, warranty, and serviceability when making your decision. Treat these tools well and they will last you a long time.

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ABOUT Patrick Peterson

Patrick Peterson of ZenHVAC has seen the HVAC industry from all angles, serving as a technician, manufacturer’s tech rep, salesman, technical trainer and business owner.