Control Panel Temperature Control

[CuriousElectron]

Hi Gents,
I have a control panel located outdoors at about 7000 ft elevation above sea level. The panel will be exposed to high and low ambient temperature throughout the year, as the weather changes to freezing cold in the winter to hot in the summer (typical of the mountainous region).
My question is - can I achieve condensation control within the panel using an air conditioner? I'm thinking about procuring a single air conditioner unit that will provide heating/cooling for the panel. All in one solution.

Can the air controller prevent condensation formation by maintaining a set point temperature control within the panel?

Thank you?
EE

 

[djs]

Not really. What is needed is to maintain the temperature inside the enclosure above the outside dew point. The dew point during winter is much lower that it is during the summer. So a setting for summer will be to hot for the heater to maintain during the winter.

 

[mfgenggear]

can you build an insulated shed a round it?
automatic thermostat control in side

 

[CuriousElectron]

Providing a shed has been proposed, but was rejected by the client. I'm failing to understand why a properly designed cooling/heating air conditioner would fail to reduce/remove the condensation? We'd be maintaining a temperature of, say, 75 degrees inside the enclosure, regardless of what the ambient temperature is.. This 75 degrees setpoint would be higher of summer/winter average dew point...

Regards,
EE

 

[mfgenggear]

probably they don't under stand the drastic weather changes, living in the high altitude weather changes fast.
in one day it rained, then hailed then snowed, then became sunny.
every thing here has to be well insulated and it's better to keep it covered if it's electronic or electrical.
maybe a steel enclosure with climate control. yet well insulated.

 

[MintJulep]

What you need to achieve is to keep the surface temperature of the inside of the enclosure and all the things inside of it above the dew-point of the air inside the enclosure.

That will be very hard to do with a small enclosure and a typical cooling coil. Because the air exiting a cooling coil is nearly saturated. In a small enclosure there is no much additional air available to dilute the moisture.

Unless the enclosure is well sealed to the exterior. In which case condensation isn't really much of a problem anyway.

 

[itsmoked]

What do the controls consist of?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[EdStainless]

But you can't seal well enough.
So the enclosure is sitting in the sun and is hot, now the sun starts to set and it cools, the air contracts and it sucks in outside air. Now this air may be fairly dry, but overnight the temp will drop another 20F (not even considering changes in weather) and even if the space is heated the skin will be cold, and likely damp. Now this process happens day after day.
If not a shed this will likely need to be a double walled (insulated) enclosure, along with the temperature and humidity control.

We used to shop overseas by ship in containers on the deck. The crates had plastic liners (double layer) that were evacuated, dry nitrogen back filled, and heat sealed. After 5 weeks in transit they would arrive with water inside them. We knew that it was condensation because the conductivity was so low (2 micromohs) but there would be a couple of quarts in each of the 12 crates in the container.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[Compositepro]

A common source of water in shipping containers is wood, in the form of pallets and crates. Dry wood is about 10% water by weight.

 

[CuriousElectron]

The control panel would be located inside a larger enclosure. Both enclosures will have continuous seal(if such thing can be achieved and maintained over time..).

The major pieces of equipment inside the control panel are microprocessor and power supply. The larger enclosure will also house a couple 12V batteries. Sounds like we need to have at least a heater in the larger enclosure..

 

[mfgenggear]

if it was made from fiberglass it could be nearly or very well sealed, , but in my earlier post I was thinking of a welded mild steel then painted box, it would
be air tight if designed right. I helped design ATM kiosk with the same issue. the entire building was formed sheet metal on a steel frame, pricy but very secure and weather proof.

 

[zeusfaber]

This sounds like a job for an anti-condensation heater. Might cost you a little more in energy consumption, but you'll make that back in maintenance.

A.

 

[MintJulep]

I think you really need to more carefully assess the need.

With proper component selection you should be able to get the things you list that are immune to the effects of condensation.

Further, preventing condensation is hard, and imposes continuous extra operating costs and maintenance.

A passive approach is better. Accept that condensation is inevitable, and cause it to happen where you want it to and drain harmlessly.

 

[itsmoked]

I'm with Mint. I'd try to vent the enclosure and make sure what's in it can take the temps or provide VERY localized heating of only what needs it. Conforming heat pads. That way you can also mange the heating with a couple of watts to keep whatever just above it's minimum temperature. The venting can then take care of the hot issue cheaply and easily as long as you supply a little shading, be it a hat type cover or something logical for the application. A/C is abhorrent for energy consumption, maintenance needs, and it's eventual failure that will bring everything down.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mfgenggear]

servers are kept in room that has climate control, because the components don't like heat. it degrades them.
heat build up is bad for electronics, I live @ 3800 ft altitude, it gets hot in the summer, and freezes in the winter.
no insulation and stuff will freeze. summer it will turn to toast.
@ 7000 ft it is worse, and depending on the region. snow, ice & freezing cold wind, summer no shade steel gets mighty hot.