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Recent content by Roach

  1. Roach

    Metric????

    Try starting a new post
  2. Roach

    Metric????

    Thanks!!!
  3. Roach

    Metric????

    Sorry for the dumb question, but the answer isnt as easy to find as you might think..... Can someone tell me the standard units for airflow in metric correlating to CFM? M^3/sec, M^3/min???? What about water flow? L/s? Thanks
  4. Roach

    ELECTRO GALVANIC?

    THANKS FOR THE INPUT. I WAS SECOND GUESSING MYSELF, BUT IT LOOKS LIKE I MADE THE RIGHT DECISION IN ISOLATING THE TWO DUCTS. BTW TOMBMECH: THE LINK YOU POSTED IS VERY INFORMATIVE THANKS AGAIN
  5. Roach

    ELECTRO GALVANIC?

    IT IS COMMON TO HAVE A DI-ELECTRIC UNION ON COPPER TO STEEL PIPE CONNECTIONS. IS THIS NECESSARY FOR DUCT CONNECTIONS AS WELL? MY UNDERSTANDING IS THAT THE WATER IS THE CATALYST FOR THE CORROSION, BUT CAN MOISTURE LADEN AIR PRODUCE SIMILAR RESULTS (I.E. COMMERCIAL DISHWASHER EXHAUST?)
  6. Roach

    electric motor heat gains

    THANKS FOR THE ANSWERS. IT MAKES SENSE THAT EVENTUALLY ALL THE POWER INPUT WILL TURN INTO HEAT FROM FRICTION LOSS. PLUS THE LOSS OF HEAT FROM MOTOR INEFFICIENCY. THAT BETTER EXPLAINS THE CHART THAT SPECIFIES WHETHER THE MOTOR, EQUIPMENT, OR BOTH ARE IN THE CONDITIONED SPACE, AND IF A FAN OR...
  7. Roach

    Telephone Equipment Room Cooling

    it is not "uncommon" practice to use a 5 ton blower (around 2000cfm) and evaporator coil with a 4 ton condensing unit. If it is a heat pump application, i might stray from this approach due to volume mismatch during refrigerant charging. Check with the equipment manufacturer. Something else to...
  8. Roach

    electric motor heat gains

    ASHRAE Fundamentals has a chart that says that an electric motor driving a fan generates as much heat as the the total power rating of the motor plus the inefficiency of the motor (assuming the fan and the motor are both in the conditioned space). This seems to negate the energy balance that...
  9. Roach

    Industrial Oven Requirements

    Does anyone have any suggestions on the proper fire prot. system for an industrial cure oven for a paint line? (Can't find anything specific in NFPA, please direct) This is a fairly large building with ovens on the mezzanine and is not fully sprinklered currently. thanks0
  10. Roach

    LMTD manipulation

    Thanks to all for the input. I intend to decrease the inlet temperature on hot side to maintain LMTD and assume similar U value. After this, I will field adjust until I reach the requirements for the process water. Roach
  11. Roach

    LMTD manipulation

    MonteMayor, To be more specific and accurate, yes this is a typo. Cold out is 185ºF. And, actually after further thought, I would prefer to not have to manipulate flow rates, although that was the intention originally. My apologies for any inferring. 25362, Yes both fluids can be assumed to be...
  12. Roach

    LMTD manipulation

    I have an existing shell and tube HX with the following design values: 190 GPM both sides Hot inlet 220ºF Hot out 200ºF Cold in 165ºF Hot out 185ºF I want my cold in and out to be 140 and 160ºF This increases my LMTD from 31 to 48 (includes correction factor for hybrid design). At the design...
  13. Roach

    pump for slurry, rubber lined vs alloy vs plastic

    I can vouch for Discflo as a very reputable pump. They withstand quite a bit of abuse in our facility. Roach
  14. Roach

    Pressure Blower with restricted intake

    Great explanation. Thanks for the clarification. "Common sense" would make me think that increasing the static pressure(fan)/head(pump) would require more torque from the motor, but as I understand it, it is all related to the total work being performed by moving the mass. Maybe my...
  15. Roach

    Pressure Blower with restricted intake

    Is this true for all centrifugal fans (squirrel cage, forward curved, backward curved, etc.)? What about centrifugal pumps? Roach
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