Ambient temperature on production floor

[Dorin]

If normal ambient temperature on production floor is 65-70°F, would there be noticeable effects on production floor equipment if we drop ambient down to 35-40°F? Equipment consists of motors, PLC's, VFD's, process instrumentation ie flow meters, chart recorders, level sensors/transmitters, pressure sensors/transmitters, temperature sensors/transmitters, 316 & 304 stainless steel sanitary tubing, enclosed fluorescent lighting, fire suppression sprinkler heads and any other standard food plant production equipment. The temperature would be brought down over a period of a couple of hours using a positive air flow equipment bringing in outside filtered air with burners off. Since outside air would be below freezing, inside ambient should reach 35-40°F fairly quickly. After about an 8 hour production run at the lowered temperature, we would bring back inside ambient to 65-70°F as quickly as our positive air flow equipment will allow(it is strictly outside air passing through filters then heated, no return). Is there a possibility of negatively affecting instruments or other equipment by attempting this drastic change in ambient temperature? Thank you in advance for taking the time to read and offer input.

 

[Jobrag]

I wouldn't expect any problems but would check that all impulse lines are free from condensation in case you ever get below freezing. I would check data sheets for the manufacturers data sheets just in case.

 

[berkeman]

If normal ambient temperature on production floor is 65-70°F, would there be noticeable effects on production floor equipment if we drop ambient down to 35-40°F? Equipment consists of motors, PLC's, VFD's, process instrumentation ie flow meters, chart recorders, level sensors/transmitters, pressure sensors/transmitters, temperature sensors/transmitters, 316 & 304 stainless steel sanitary tubing, enclosed fluorescent lighting, fire suppression sprinkler heads and any other standard food plant production equipment. The temperature would be brought down over a period of a couple of hours using a positive air flow equipment bringing in outside filtered air with burners off. Since outside air would be below freezing, inside ambient should reach 35-40°F fairly quickly. After about an 8 hour production run at the lowered temperature, we would bring back inside ambient to 65-70°F as quickly as our positive air flow equipment will allow(it is strictly outside air passing through filters then heated, no return). Is there a possibility of negatively affecting instruments or other equipment by attempting this drastic change in ambient temperature? Thank you in advance for taking the time to read and offer input.

How many times are you planning on doing this? If it's just a time or two, I agree with Jobrag. But, if you want to do this for all production days from now on, that kind of temperature cycling may cause electro-mechanical fatigue in some of your equipment, shortening the lifetime of that equipment.

 

[Dorin]

How many times are you planning on doing this? If it's just a time or two, I agree with Jobrag. But, if you want to do this for all production days from now on, that kind of temperature cycling may cause electro-mechanical fatigue in some of your equipment, shortening the lifetime of that equipment.

This is intended to happen once a year for the duration of one 8-12 hour shift (we run 2 daily shifts year round). Then it's back to normal ambient of 65-70°F.

 

[CWatters]

Warm humid air coming into contact with cold soaked metal might cause condensation to form. Perhaps hang a cold metal plate in front of the incoming vents and check for condensation? Not sure what to recommend if you get some. Air conditioning?

 

[mrspeedybob]

Warm humid air coming into contact with cold soaked metal might cause condensation to form. Perhaps hang a cold metal plate in front of the incoming vents and check for condensation? Not sure what to recommend if you get some. Air conditioning?

That's going to depend on how the air gets warmed up.
Cold outside air that is passed through a heat exchanger to warm it up will contain the same amount of moisture at it did before being heated, relative humidity will be lower. Passing this air over cold equipment should not cause a condensation problem.
If the heating process involves unvented burners of some sort the exhaust from the burners will contain water vapor which could condense on cold equipment.

 

[Dorin]

Thank you all; the test should happen next week. I'll post an update soon thereafter.