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Application Guide

Enclosure Cooling Selection Guide

Use a Filterfan when the plant air is clean and at least 10°F cooler than the most the panel can run at. Use an enclosure air conditioner when the plant air gets as hot as the panel, or the air is dirty, oily or wet. Heat exchangers fill the gap in between, and a chiller is for process cooling. The tables below give the numbers, a worked example and the Pfannenberg part families for each case.

Run the Heat Load Calculator Get Free Sizing Help

Step 1: What Are Your Three Key Variables?

Before selecting a cooling technology, you need three numbers. If you don't have these, the heat load calculator works them out from your drive horsepower, enclosure size and temperatures.

Qtotal

Total Heat Load (Watts)

Sum of heat dissipated by all drives, PLCs, power supplies, and other components inside the enclosure.

Tamb

Max Ambient Temp (°F/°C)

Highest temperature outside the enclosure during normal operation. Include seasonal peaks.

Ttarget

Target Internal Temp (°F/°C)

Maximum allowable temperature inside the enclosure, per component datasheets (typically 95 to 120°F).

Step 2: Choose Your Cooling Technology

The relationship between ambient temperature and target internal temperature determines your primary cooling approach.

Enclosure cooling selection chart: answer four questions from the top down. Process cooling means a chiller. Washdown or corrosive areas with plant water mean an air-to-water heat exchanger. Plant air at or above the target temperature means an air conditioner. Dirty, humid or oily air below the target means an air-to-air heat exchanger. Clean air cooler than the panel means a Filterfan. Cooling a process, not the panel?Spindle, mold, laser or weld waterYesIndustrial chillerEB and CCE seriesNoWashdown, corrosive or extreme heat,and plant water on hand?YesAir-to-water heat exchangerPWS series, sealed cabinetNoIs plant air ever at or above thetarget temperature inside the panel?YesEnclosure air conditionerDTS seriesNoIs the plant air dirty, humid or oily?Dust, fibers, coolant or oil mistYesAir-to-air heat exchangerPKS series, closed loopNoFilterfanPF series, the lowest cost optionOutdoors, or cold enough to sweat?Add a heater with a thermostat or hygrostat to any of the above to stop condensation.Cooling a process, not the panel?Spindle, mold, laser or weld waterYesIndustrial chillerEB and CCE seriesNoWashdown, corrosive or extremeheat, and plant water on hand?YesAir-to-water heat exchangerPWS seriesNoPlant air ever at or above thetarget temperature in the panel?YesEnclosure air conditionerDTS seriesNoPlant air dirty, humid or oily?Dust, fibers, coolant or oil mistYesAir-to-air heat exchangerPKS series, closed loopNoFilterfanPF series, the lowest cost optionOutdoors, or cold enough to sweat?Add a heater with a thermostat orhygrostat to stop condensation.

Start at the top and stop at the first Yes. The table below gives the same answers with relative cost.

If Your Situation Is... Use This Pfannenberg Product Relative Cost
Ambient always < target temp, clean air, indoor Filterfan® Filterfan 4.0 Series Lowest
Ambient at or above target temp, or dirty, humid or oily air Cooling Unit (Enclosure A/C) DTS 3000 Series Mid
Small temperature difference, closed loop needed, no refrigerant desired Air-to-Air Heat Exchanger PKS Series (Kinetic System™) Mid
Extreme ambient, corrosive, washdown, plant water available Air-to-Water Heat Exchanger PWS Series (NEMA 4X SS available) Higher
Process cooling (spindles, injection mold, lasers) Industrial Chiller CCE / EB 2.0 Series Highest
Outdoor, cold climate, condensation risk Heater + Thermostat/Hygrostat FLH Fan Heaters + Thermostats Lowest

Not Sure Which One You Need?

Run the enclosure heat load calculator. It takes your drive horsepower or component watts, enclosure size and temperatures, returns the load in BTU/hr, tells you whether a Filterfan will hold it, and lists the Pfannenberg units rated for the result at 95°F/95°F. Send us the result and we confirm it against the performance curve and quote it. Replacing a Hoffman, Rittal or Saginaw unit? Use the air conditioner cross reference.

Step 3: Check the Choice With Numbers

Each cooling type has one number that decides if it works. Find yours in the left column.

Cooling type It works when Number to size it by Range on this site
Filterfan (PF series) Plant air is clean and at least 10°F below the target inside the panel Airflow: CFM = BTU/hr ÷ (1.08 × ΔT°F) PF 11000 at 17 CFM up to PF 67000 at 560 CFM, NEMA 12 and NEMA 3R versions
Air-to-air heat exchanger (PKS series) Plant air stays below the target, but it is dirty, oily or wet, so the panel must stay sealed Watts moved per degree of difference (W/°F) at your ΔT PKS Mini (PKS3042A115N4SS) up to PKS 336X (PKS3364A460N4SS), NEMA 12, 3R/4 and 4X stainless. See air conditioner vs heat exchanger
Enclosure air conditioner (DTS, DTT, DTI series) Plant air reaches or passes the target, any air quality BTU/hr at 95°F outside and 95°F inside (the rating point), then the curve at your hottest day DTS 3021 at 900 to 1,300 BTU/hr and up; NEMA 12, 3R/4 and 4/4X stainless
Air-to-water heat exchanger (PWS series) Plant or chiller water is colder than the target, often washdown or very hot rooms Watts at your water temperature and flow Quoted to the load. Send water temp and GPM
Chiller (CCE, EB series) You are cooling a process loop: spindle, mold, laser or weld kW of heat at your fluid temperature CCE 6301 at 2.4 kW up to EB 440 at 44.4 kW

Worked example: 600 W panel

A panel holds a drive and a power supply that give off 600 W total. The parts inside are good to 104°F.

Step Math Result
Convert to BTU/hr 600 W × 3.412 2,047 BTU/hr
Add 20% margin 2,047 × 1.2 2,457 BTU/hr
Case A: plant air tops out at 89°F (15°F cooler) 2,457 ÷ (1.08 × 15) 152 CFM. A PF 43000 is 156 CFM free-blowing; with the filter in place airflow drops, so check the curve or step up to the PF 65000 at 297 CFM
Case B: plant air hits 110°F Plant air is hotter than 104°F, so no fan or air-to-air exchanger can work Air conditioner sized for 2,457 BTU/hr at 110°F. The DTS 3061 and DTS 3081 are listed at 2,000 to 3,000 BTU/hr; send us the numbers and we read the curve at 110°F

Math notes: 1 W = 3.412 BTU/hr. CFM = BTU/hr ÷ (1.08 × ΔT°F) is the standard sensible heat formula for air near sea level. Part ranges come from the Pfannenberg part numbers listed on this site. Air conditioner ratings are at 95°F/95°F per the Pfannenberg datasheets; output drops as the room gets hotter. The 10°F minimum gap is the rule our heat load calculator uses.

Step 4: Match Your Enclosure Rating

Not sure which rating the panel needs? See NEMA 4 vs 4X vs 12 enclosure ratings.

Your cooling solution must be compatible with your enclosure's NEMA rating and construction. Applied Control supplies both the enclosure and the thermal management, so we can spec a complete package.

Indoor / NEMA 12

Hammond steel enclosures + Filterfans or cooling units. Most standard factory environments.

Outdoor / NEMA 4

Hammond NEMA 4 enclosures + DTS 3000 cooling units + heaters for cold climates.

Washdown / NEMA 4X

Stahlin fiberglass or Hammond stainless + NEMA 4X cooling units or PWS heat exchangers.

Corrosive / Chemical

Stahlin non-metallic enclosures + stainless PWS heat exchangers for closed-loop protection.

Ratings you can get by cooling type

Panel rating Filterfan Air conditioner Where to look
NEMA 12 (indoor, dust and drips) PF series, NEMA 12 versions DTS 3021 and up, NEMA 12 Hammond steel enclosures
NEMA 3R (outdoor, rain) PF series, NEMA 3R versions DTS 3031 and DTS 3061, NEMA 3R/4 Enclosures
NEMA 4 (hose-down water) No. A fan opening cannot hold a hose test DTS 3031 and DTS 3061, NEMA 3R/4 Enclosures
NEMA 4X (hose-down plus corrosion) No DTS 3081 and DTS 3185, NEMA 4/4X in 304 or 316 stainless Stahlin fiberglass or Hammond stainless

Ratings per NEMA 250 and the Pfannenberg part numbers listed on this site. A cooling unit must carry the same rating as the enclosure or it lowers the panel rating.

Common Questions

Can I use a fan if the plant is hot in summer?

Only if the plant air on the hottest day stays at least 10°F below the panel target. If it ever reaches the target, the fan pushes hot air in and you need an air conditioner.

Why not just put an air conditioner on every panel?

You can, and it works at any room temperature. A Filterfan uses far less power and has no refrigerant, so it is the first pick when the air is clean and cool enough.

Heat exchanger or air conditioner?

A sealed air-to-air heat exchanger works when the room stays at least 10°C (18°F) below the panel target, and it runs on fan power only. Once the room gets that hot, you need an air conditioner. See enclosure air conditioner vs heat exchanger for the side by side table and a sizing example.

Do I need a heater too?

Outdoors or in an unheated building, yes. A small heater with a thermostat or hygrostat keeps the panel above the dew point so water does not form on the parts.

I am replacing a Hoffman, Rittal or Saginaw unit. Where do I start?

Use the air conditioner cross reference. Send the old model number and we confirm the Pfannenberg match against the cutout and the load.

What do you need from me to size it?

Total watts inside the panel (or drive horsepower), the enclosure size, the hottest plant air temperature and the highest temperature the parts can take. The heat load calculator works it out in a minute.

Cold or damp site? The same box may need heat in winter. See enclosure heaters (Hammond FLHTF and Pfannenberg FLH, 30 to 1,300 W) and the Hoffman DAH heater cross reference, which also has the heater sizing formula.

Get a Complete Enclosure + Cooling Package Quote

Tell us your application, heat load, environment, and NEMA requirements. We recommend the right enclosure and thermal management combination with pricing.

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