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Thanks!!!

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

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

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?)

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...

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...

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...

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

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

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...

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...

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

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...

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

Please correct my thinking.... A direct drive fan will turn a constant (within reason) RPM, and the fan will try to emit a set air volume per revolution (CFM). If I restrict the intake, it seems to me that it would reqiure more mork to move this volume of air. Pumps try to deliver a certain...

I have seen levitation performed with a unit designed for induction heating. The material that is lifted plays a crucial role of course (must be ferrous). Don't knoa how it worked, but it worked. Roach

I have a pressure blower with a restricted intake. When I open the intake fully (no restriction) my motor pulls FLA (I have blown fuses). When I close it (restrict air flow) it goes down to idle (normal amperage on the motor). I would think that restriction to intake causes the motor to work...

Thanks for the answer. This is common sense, although not so common in my case. Thanks again.

Can someone explain why if I ground both ends of a shielded cable carrying DC signals in a wireway with AC current carrying wires, I get noise, but if I ground just one end, I don't? Thanks