Email us

Outdoor, heat and moisture

Every engineering article on outdoor, heat and moisture, newest first: specific questions from the plant floor and the panel shop, answered one at a time.

Subject

All articles on outdoor, heat and moisture

Every subject
  1. Oct 29, 2026Sheltered NEMA 3R switchboard or NEMA 4X near the coastA shelter around a NEMA 3R switchboard versus a NEMA 4X enclosure near the coast: salt entry, condensation, clearances and which one costs less over its life.Comparison
  2. Oct 28, 2026When an outdoor enclosure needs an anti-condensation heaterHow to decide between an anti-condensation heater, a breather or desiccant for an outdoor enclosure, and how to size and control the heater you specify.How-to
  3. Oct 28, 2026VFD enclosure: rating, size and cooling for one drivePick the NEMA rating, size a sealed box for one VFD's heat load, and choose between vents, a fan or closed-loop cooling. Numbers and an order list.Selection guide
  4. Oct 28, 2026Thermoelectric enclosure cooler vs air conditioner: which to specifyWhen a Peltier thermoelectric cooler beats a compressor air conditioner on a sealed NEMA 4X stainless enclosure: heat loads, washdown, mounting and cost.Comparison
  5. Oct 28, 2026Solar shield for an outdoor electronics enclosure: the numbersSize a sun shield for a pole-mounted electronics enclosure: standoff, air gap, reflectivity and the solar load your cooling still has to handle.How-to
  6. Oct 28, 2026Solar heat load on an outdoor enclosure and the temperature riseHow much direct sun raises an outdoor enclosure above ambient air, how to estimate it from irradiance, finish and area, and when to size cooling for it.Explainer
  7. Oct 28, 2026Small outdoor enclosure for a wireless radio boardPick a small outdoor stainless enclosure for a wireless radio or router board: the rating, the size, the cutouts and what to put on the order.Selection guide
  8. Oct 28, 2026Sealing connectors inside an outdoor junction boxSeal connectors inside an outdoor junction box the right way: rated boxes, glands, dielectric grease, self-fusing tape and condensation control.How-to
  9. Oct 28, 2026Sealing a junction box to a brick wall against running waterHow to seal a wall-mount junction box to uneven brick or block so water running down the wall cannot get behind it or through the rear cable entry.How-to
  10. Oct 28, 2026Removing heat from a small sealed IP66 enclosureHow to remove heat from a sealed IP66 enclosure using metal walls, spreader plates and external fins, with temperature checks before active cooling.Explainer
  11. Oct 28, 2026Putting a fan on a NEMA 4X enclosure: what it costs youA fan hole breaks the NEMA 4X / IP66 seal. What each cooling option preserves, and how to keep a sealed enclosure cool anyway.Explainer
  12. Oct 28, 2026Passive vents or a fan for electronics in a sealed garage boxSize the heat load from an NVR, router and UPS in a sealed garage box, then decide between passive vents and a filtered fan without losing the rating.Selection guide
  13. Oct 28, 2026Panel mount indicators on an outdoor enclosureHow to pick panel mount indicators that keep a NEMA 3R or 4X outdoor enclosure rated, and what cutout and gasket details to specify.Selection guide
  14. Oct 28, 2026Outdoor junction box for camera wiring: what to specifyHow to size, rate and order an outdoor junction box for camera wiring: NEMA 4X material, gland positions, drip loops and the spec to send.Selection guide
  15. Oct 28, 2026Outdoor enclosure for networking equipment: seals and entryPick a stainless outdoor enclosure for routers, switches and radios: sealed Ethernet entry, glands, drip loops, heat and condensation handled. Spec it here.Selection guide
  16. Oct 28, 2026Outdoor enclosure for a PoE switch and UPSPick the rating, size, cooling and mounting for an outdoor enclosure running a PoE switch and a small UPS, with a heat budget and battery temperature limits.Selection guide
  17. Oct 28, 2026Outdoor enclosure for a fanless router in extreme temperaturesSpec a sealed outdoor network enclosure for a router that sees -4 F winters and 130 F summer internals: size, sun shielding, heat, and what to order.Selection guide
  18. Oct 28, 2026Moisture in an outdoor enclosure and corroded RJ45 connectorsWater collects in sealed outdoor enclosures and corrodes RJ45 pass-throughs. Map the symptoms to causes and fix breathing, glands, grease and drainage.Troubleshooting
  19. Oct 28, 2026Keeping electronics warm in an unheated outdoor enclosureHow to keep radios and routers above their minimum operating temperature in an unheated outdoor electrical enclosure: heat budget, heaters and sealing.How-to
  20. Oct 28, 2026Junction box breather and drain requirements by volumeUnderstand junction box breather and drain requirements, the 2,000 cm³ cutoff, fitting selection, and how to preserve enclosure protection.Explainer
  21. Oct 28, 2026How to vent a gas sensor without losing the enclosure ratingA sealed NEMA 4X box makes a CO2 or gas sensor read slow and stale. Vent it with breather vents and membranes while keeping the rating intact.Explainer
  22. Oct 28, 2026How a sun shield cuts solar heat load on an enclosureHow much a sun shield really cuts the solar heat load on an outdoor enclosure, and how to put a defensible number into your heat balance instead of guessing.Explainer
  23. Oct 28, 2026Gas accumulation in sealed enclosures: why it happensHow hydrogen and other gases build up inside a sealed electrical enclosure, what the rating does not protect against, and when a vented design is the answer.Explainer
  24. Oct 28, 2026Fiber trunk and PoE switch enclosure for outdoor camera installsSize, rate and seal an outdoor enclosure that takes a fiber trunk, a PoE switch and gland entries for camera runs, and know exactly what to order.Selection guide
  25. Oct 28, 2026Enclosure cooling: fan vs air conditioner vs heat exchangerCompare enclosure fans, air conditioners and heat exchangers by ambient temperature, heat load, sealing needs and mounting cutouts before ordering.Comparison
  26. Oct 28, 2026Conformal coating or a sealed inner enclosure for outdoor boardsCompare conformal coating with a sealed inner box or outer enclosure for outdoor boards: humidity, salt air, rework, heat and what to order.Comparison
  27. Oct 28, 2026Conformal coating in outdoor enclosures: when it helpsConformal coating in outdoor enclosures adds board protection, but cannot replace sealing, moisture control, connector protection or thermal checks.Explainer
  28. Oct 28, 2026Conformal coating in a ventilated NEMA 4 enclosureVenting a NEMA 4 enclosure for outdoor use ends the dust and moisture seal. What that does to your electronics and when conformal coating becomes necessary.Explainer
  29. Oct 28, 2026Condensation in an IP67 project box: fix the cable entryMoisture in a small sealed outdoor electronics box: tell a gland leak from condensation, seal the cable entry, and stop it coming back.Troubleshooting
  30. Oct 28, 2026Condensation in a sealed enclosure: why the rating can't stop itCondensation in a sealed enclosure can wet electronics despite its ingress rating. Compare desiccant, coating, heaters and membrane vents.Explainer
  31. Oct 28, 2026Coastal outdoor enclosure for radios: salt, dust and heatPick material, NEMA 4X / IP66 rating, size and cooling for a radio enclosure on a salty, dusty coast with 50 C days. What to order and how to keep the seal.Selection guide
  32. Oct 28, 2026Closed-loop enclosure cooling where fumes are in the airHow to cool a control enclosure in fume-laden, humid plant air without pulling contaminants inside: heat exchangers, air conditioners, sizing and condensate.Comparison
  33. Oct 28, 2026Cabinet air conditioner sizing for an overheating enclosureSize a cabinet air conditioner step by step: heat load math, mounting position, cutout sealing, condensate drain and the checks that keep the rating intact.How-to
  34. Oct 28, 2026Breather vent vs drain for a sealed enclosureMembrane breather vent or drain: which stops condensation in a sealed outdoor enclosure, when each works, and what to specify. Numbers and the decision.Comparison

Buying guides

The fundamentals behind these answers

All guides

Guide

Outdoor enclosures

Which NEMA type for rain, hose and salt, how much heat the sun adds, colour and sun shields, cold nights, UV and mounting.

Read the guide

Guide

Heat calculation

Heat load, allowed temperature rise, surface-area dissipation, solar gain and cooling sizing, worked through one enclosure with the arithmetic shown.

Read the guide

Guide

Condensation

Dew point table, why sealed boxes breathe, heater sizing with a worked example, rated vent drains, desiccant and air conditioner condensate.

Read the guide

Guide

Washdown enclosures

What FDA, USDA, 3-A and EHEDG say, NEMA 4X vs IP69, hygienic design, mounting, 304 vs 316L against sanitizers, and cleaning practice.

Read the guide

Ratings on this site are manufacturer ratings; not UL listed. NEMA does not test, certify or endorse enclosures.