Enclosure - Replace with larger SS type #17
Description
The EB Groundstation Enclosure has been determined to be too small for the equipment housed in it causing a maintenance struggle, and of a material not conducive to being exposed to high levels of sunlight causing considerable increased internal temperature during sunny days.
We have a potential solution for the enclosure thermal issue, and a test to confirm this that is ready to go up onto the roof.
Some background discussion;
• The amount of equipment in this enclosure is a considerable up-scope from the initial design. This demonstrates the notion that one should never choose an enclosure until all design work is complete, and then future room to expand-into should be considered. We were even adding things as late as last week, and Miles and I have plans to add "just one last thing!" This enclosure may have been chosen too early in haste and I am fully responsible for that, but it had to be done at that early time.
• Other than possibly helping to reduce thermal extremes, a larger enclosure would allow easier access to components for maintenance, and provide a neater more professional appearance. Being as full as our enclosure is, you can't really see how neat things really are down under all the layers. 🙃
• From my (bragging => significant experience) with enclosures outdoors, the best way to learn how dirty Portland air is would be to put a thermostatically controlled fan pulling external air through a filter onto an enclosure. Even up on a roof, the dirt ingested is significant. Fans pulling external air are totally acceptable for indoor (server, telecom, equipment) rooms, but when outdoors other solutions are needed.
• My experience shows enclosures made out of stainless steel do a lot better when exposed to direct sunlight. SS is quite reflective, and also a somewhat poor thermal conductor. Whereas I have seen many enclosures get up to 50 deg C (like ours does now) year after year, and the equipment continues to work reliably (even radio equipment) the SS enclosures often peak out at around 10 to 15 degrees cooler. (That is hint #1)
• Temperatures getting up to what we are seeing is unacceptable when there are batteries (especially large storage batteries) or things that are particularly susceptible to drift over temperature such as analog or frequency processing. Yes, Miles and I are also thinking about adding a GPS disciplined local oscillator, but we are not seeing frequency drift at this time.
• So it is said, "any good idea without supporting data is just another opinion!"
I have some data!:upside_down_face:
(1) On cloudy days, the temperature gets up to around 35 to 38 degrees C.
(2) At night the enclosure cools down to around 14 deg C, depending on how cool the night is.
(3) On sunny days the temp gets up to 50 deg C at later times of the day such as 1700 local time.
(4) All of these cases are with all equipment running (except transmitters, which would only be on for very short periods anyway).
This means, the heat generated by the equipment itself is not causing the excessive temperatures.
The excessive heat is caused by sunlight impinging on the gray steel enclosure.
My immediate solution:
Other than replacing the enclosure with a larger SS box, which would cost somewhere around $1000, we could cover the enclosure with reflective insulated panels. I have an insulated reflective box right now that could go up to the roof at any time to confirm this idea. It is made from the material I propose we use. (edited)
Clarification:
I have an insulated reflective box that could fit over the groundstation enclosure.
This would just be for a test to confirm the idea.