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Recent content by CnoJ

  1. CnoJ

    Measuring airflow into large electrical enclosure

    I had kinda hinted at this method in my OP ;)
  2. CnoJ

    Measuring airflow into large electrical enclosure

    Littleinch, I'm having trouble understanding your post. Could you please elaborate? If yo can measure airflow with any element at 90 degrees to the entrance then you can determine overall air flow. I suggested that flow is unlikely to be perpendicular to the intake (filter surface). Are you...
  3. CnoJ

    Measuring airflow into large electrical enclosure

    Mintjuliep, do you know of a similar hood thats good for 2000 CFM or more? Also one large enough for my .5 m2 inlets?
  4. CnoJ

    Measuring airflow into large electrical enclosure

    Littleinch what are you asking for drawings of? My questions above were aimed at you re. your previous post.
  5. CnoJ

    Measuring airflow into large electrical enclosure

    Are you saying take speed measurements right at the intake? I'm not expecting flow to be perpendicular to the inlet filter as there are so many obstructions inside the enclosure. Are there anemometers that will measure air speed regardless of direction? This is why I was considering using a duct...
  6. CnoJ

    Measuring airflow into large electrical enclosure

    Hi, I need to measure flow rate through some approx. .5 m2 inlets that supply cooling air to some large, densely packed enclosures. Flow rate is around 500-2000 cfm per inlet, driven by backward curved radial blowers making up to 700Pa. The inlets are basically rectangular holes through the...
  7. CnoJ

    Best air flow measurement method?

    I haven't found a hood that will cover my CFM range, they seem to stop around 2500 CFM. Would a pitot grid be my next best option? Is there such a thing as a hot wire anemometer grid?
  8. CnoJ

    Best air flow measurement method?

    Hi, I often need to know mass flow rate through air cooled industrial equipment and usually struggle to get repeatable measurements using vane or hot wire anemometers. I can only measure at the intakes, which are up to 700mm (~28") sq with flow in the 1500 to 5000 CFM range. Fan pressure is...
  9. CnoJ

    Confused - Fan pulling air through a heat sink

    Well I already know the max and min kg/s I need to pull thru the sink, the kW I'm sinking, and I have system curves for the sink and for the enclosure. So now I have have to find a fan that will pull the required kg/s. I'm thinking I should increase the sink system curve CFM by the volume...
  10. CnoJ

    Confused - Fan pulling air through a heat sink

    OK. So for fan choice my system curve should use CFM exiting the sink?
  11. CnoJ

    Confused - Fan pulling air through a heat sink

    Hi, I have a cooling application that needs fans downstream of a heat source. When I try to account for the air density change (hot air at fan) I run into this problem: -A fan pulls air through a heat sink. -Constant heat is applied to the sink. Its exhaust temp rises and air density drops...

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