DIY: Portable Cooling Unit

writ­ten 7/14/25; updat­ed 7/14/25

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What

Make your own air con­di­tion­er that’s not real­ly air con­di­tion­ing. This device made from house­hold items helps blow cold air from water chilled by ice. It is high­ly cus­tomiz­able. Best for small spaces.

Why

The use case for this assem­bly can be var­ied. Exam­ples: the top of my town­house that nev­er gets A/C prop­er­ly, pic­nics, tail­gat­ing, my work­place when­ev­er it los­es A/C (at least once a year), etc.

Time and Effort

Time: 2–3 hours

Effort: Easy-Mod­er­ate

Materials and Cost

Mate­ri­als

Sub­mersible Pump USB, 3W/50gph

Arc­tic Zone Titan Cool­er, 16-can

Radi­a­tor w/ Fan, 120mm/DC12V/12pipe

Tub­ing, 3/8″-1/2″ (0.3″-05″; 8–12mm)

Dual 3 or 4‑pin USB Adapter, 12V

4in Dust Hose, sculptable/flexible

4in Bell Noz­zle Dust Col­lec­tion Fit­ting

USB Hub with Pow­er Switch­es, 2.5A/5V

Cost

$6.99

$27.99 (sale)

$20.99

Free (~$6)

$8.99

$15.45

$19.98

$19.99

TOTAL: $120.39 ($126.39)

Owned Sup­plies

Sharpie

Dremel w/Cutting Bit

Dri­ver w/Drill Bit

Screws, Nuts, Wash­ers

Util­i­ty Knife

Ruler/Square

Safe­ty Glass­es

Option­al — the assem­bly is high­ly cus­tomiz­able

  • 120mm Slim Case Fan attached to oth­er side of radi­a­tor for push/pull method (~$10)
  • Replace the 120mm Radi­a­tor w/Fan with a 240mm Radi­a­tor w/Fan ($36.99), Slim Case Fan 3‑pack w/PWM shar­ing ($28.99)
  • Add anoth­er Fan to the end of the Flex Hose for even more pulling pow­er (~$10-$30), by uti­liz­ing a 3D print­er or buy­ing a Duct Col­lec­tor Flange (~$10)
  • If you don’t need the on/off switch­es for pow­er, then just a dual port USB A pow­er block is fine (~$10)
  • You can also get a USB split­ter plus an in-line USB with on/off switch all con­nect­ed to a 1‑port wall block, but that would mean many adapters and could com­pro­mise pow­er deliv­ery if not care­ful
  • Use an insu­lat­ing tape around the base of the Bell Attach­ment

Schematics

This is the orig­i­nal schemat­ic I drew. It has dif­fer­ent com­po­nents I did­n’t end up using like wing nuts, a divert­er tray at the bot­tom, and an added plas­tic sheet/bracket for fas­ten­ing the hose flange on top to.

Process

Planning and Measurements

  • After gath­er­ing sup­plies, try them out to see if they will fit, the best ori­en­ta­tion, etc. Adjust as nec­es­sary
  • Cut Hoses to fit the Sub­mersible Pump and Radi­a­tor w/Fan into reser­voir (orange lin­er buck­et)
  • Decide if you want to use the push or pull method (or both) for the radi­a­tor, and swap the fan to the desired side

Note: Cool­er fans always have a direc­tion of flow and spin indi­ca­tor some­where on there

  • Take mea­sure­ments and mark them with the Sharpie
Notch­es for cords

Cutting

  • As nerve-wrack­ing as it can be, you just got­ta do it to get it done
  • Start with the notch­es in the plas­tic. I used a Dremel with a cut­ting wheel and it was quite sim­ple. *Don’t for­get safe­ty glass­es when cut­ting plas­tic!!*
Dremels make the plas­tic melt while cut­ting
It’s use­ful for keep­ing things most­ly smooth
  • Now for the cool­er. I decid­ed to trace the inside of the Bell Noz­zle Attach­ment to open up as much space as pos­si­ble for the air move­ment (plan­ning on lat­er using a 240mm instead of just the 120mm). Using the util­i­ty knife, I cut through the 3 lay­ers of insu­lat­ing mate­r­i­al
  • Ini­tial­ly, I’d planned on just set­ting the Bell Attach­ment on top of the cool­er, so next, I drilled holes for the 4 attach­ment points through insu­lat­ing mate­r­i­al and the orange plas­tic (need­ed to stand on a stool to do this on the work­bench) using a 1⁄4″ bit
  • Then, I traced the open­ing on the plas­tic with a Sharpie because now I can see the line through the back­side. It’s time to cut the open­ing! Here, you have options. I think the eas­i­est method is to run the util­i­ty knife mul­ti­ple times around the shape, cut­ting deep­er each time, then clean up with the Dremel (sand­ing bit) after­wards (unless you have oth­er fun tools in your arse­nal). Instead, I decid­ed to get fan­cy and use avi­a­tor snips (tin snips) because they pret­ty much cut every­thing. The prob­lem is that you have to know how to use them oth­er­wise you mess up like I did. Thank­ful­ly, it was­n’t a huge deal. It real­ly does­n’t have to be gor­geous, either.
Right side snips. Not sure where my left one is…
Oops. Tried to the the cen­ter snips

Securement

  • Here, you have to decide how you want to mount the Bell Attach­ment: Under the insu­la­tion? Above? And, even, if you want to secure it on top of the cool­er fab­ric, or under­neath it, just on the orange plas­tic.
Under?
Above?
  • I hap­pen to have a huge box of loose screws orga­nized by size, and some ran­dom wash­ers and nuts, so I chose some 1⁄4″ (M6) screws
  • Ini­tial­ly, I used the 1″ screws, wash­ers, and nuts to go all the way through.
  • In the end, I changed my mind used the 1⁄2″ length screws and attached it all under­neath the cool­er fab­ric because the 1″ screws were too long even through the fab­ric and would impede the fan/radiator place­ment inside

Final Assembly and Testing

Time to put it all togeth­er!

  • First up, replace the orange lin­er buck­et, suc­tion the Sub­mersible Pump to the bot­tom, and replace the tray with the Pump’s cord through the notch
  • Fit the water tubes down into the reser­voir through the tray’s con­ve­nient holes (bonus, this sta­bi­lizes the radiator/fan unit) and attach to the Pump
  • Attach all Pow­er Cords and Adapters togeth­er
  • Attach the Flex­i­ble Hose to the Bell Attach­ment

Time to Test!

  • Move the tray aside a lit­tle, and fill ‘er up with water (make sure it’s always past the top of the Pump… You should nev­er run those dry!) and ice packs. I hap­pened to use ice because I ran out of ice packs test­ing out the first iter­a­tion of this assem­bly (see end of post if inter­est­ed)
  • Plug it all in
Fill­ing up!
Water is drain­ing into the reser­voir just like it’s sup­posed to!
  • DONE! Give it some time to start cool­ing
Hel­lo!!

Result

07/14/25: The pow­er real­ly isn’t as strong as I’d like it to be. End­ed up try­ing all kinds of fans (hap­pened to have) to try and boost pow­er. More mon­ey equals more pow­er, but also more noise… With that said, hav­ing this when it’s about 100F with no oth­er air source, would be a God­send.

The cool­er is insane­ly portable, and every­thing about this cool­er by Arc­tic Zone is per­fect for this appli­ca­tion from the tray with con­ve­nient holes to the zip­per-less clo­sure, to the plas­tic lin­er tray which makes it ful­ly water­proof, to just how nice it looks. It even comes in a 48-Can size!! Tech­ni­cal­ly, you can just scoot the tray aside and car­ry drinks in the reser­voir, too. Even food if you have space in the tray. I’m sure you can 3D print any man­ner of dividers if you’re not using the whole tray for fans. The largest sized cool­er could real­ly have dual fan and vent set­up.

Just store the cords and block in the pock­ets when not using
Lift out and pour water. Easy peasey.

Here is a hose-end fan attached with a 3D print­ed 4″ adapter

When I have more monies, I will try the 240mm Radi­a­tor with push and pull fans, then update here.

Notes

  • Your choice on how you want to ori­ent the fan on the radi­a­tor. You can unscrew and re-screw to the oth­er side, or even add anoth­er fan for a push/pull method instead of just push or pull
  • Many soft-sided cool­ers are NOT actu­al­ly water­proof! Be care­ful!
  • Sub­mersible pumps are eas­i­ly clogged. You do not need a pow­er­ful one. A weak­er one will do just fine
  • Ice packs are prefer­able to actu­al ice, though you can use ice itself, too. The rea­son being tiny ice pieces can enter the pump and poten­tial­ly dam­age the entire sys­tem
  • Very large chunks of ice do not melt eas­i­ly or quick­ly, and can pro­vide longer cool­ing than small pieces
  • This can also be done in a hard­case cool­er. I chose this cool­er because drilling through plas­tic of a hard cool­er would like­ly neces­si­tate some sort of seal­ing to retain the insu­lat­ing abil­i­ties of the cool­er. Like, spray foam or insu­lat­ing tape?

Test Run

If you’re inter­est­ed, I ini­tial­ly test­ed it all out on a small cooler/lunch bag that was free. I’d drawn schemat­ics for 2 dif­fer­ent setups includ­ing the small­er set­up. The result was less than ide­al:

  • The fan and radi­a­tor were much too large for the front pock­et that I’d planned on try­ing
  • Pok­ing holes through the bag to the reser­voir of water is not idea for leak­age rea­sons, yet run­ning the hoses around the out­side along­side the pow­er cords made for a very ugly set­up and high chance for leak­ing, not to men­tion reduced water-cool­ing capa­bil­i­ties
    • The cooler/lunch box end­ed up leak­ing because it’s not actu­al­ly water­proof

Here are some pic­tures!

Orig­i­nal Schemat­ic
Just need a util­i­ty knife to score and break
Mount­ed!
Pump goes in, but has no hard sur­face to suc­tion to
Too tight a fit, so the hoses have to stick up and out
Clos­ing it inside the pock­et kinks the hoses
Pump and radi­a­tor work well!
For ref­er­ence, the counter out­side it was 69F
In the end it leaked every­where and was a bust

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EV Charging Station Statistics Comparison

writ­ten 07/22/23, updat­ed 07/22/23

Pur­pose

Bat­tery elec­tric vehi­cle (EV/BEV) charg­ing sta­tion com­par­i­son

Vehi­cle

2023 Ford Mus­tang Mach-E4, Select, Stan­dard Range (70kWh capac­i­ty, 110kW DC max charge)

Loca­tion

North­ern VA

Companies/Stations

Blink, EVgo, Home (120V), Sema­Con­nect (now absorbed by Blink), Vol­ta

Dura­tion

Start Date: Jan­u­ary 21, 2023 — cur­rent

Notes

Aver­age is cal­cu­lat­ed for all, with Medi­an mea­sured when ample data acquired

Charging Stations (A‑Z)

  1. Charg­ing Sta­tions (A‑Z)
    1. Blink Charg­ing
    2. EVgo
    3. Home 1 (120V) — exten­sion cord
    4. Home 2 (120V) — no exten­sion cord
    5. Sema­Con­nect (now defunct)
    6. Vol­ta Charg­ing
  • Amer­i­can charg­ing com­pa­ny based in Mia­mi, FL.
  • 1 of 3 charg­ing com­pa­nies con­tract­ed by USPS to pro­vide charg­ing.
  • Acquired Sema­Con­nect June 2022.

*My usage of Blink is the same hard­ware as Sema­Con­nect I’d used for half the year. First use of Blink was June 30, 2023

Blink Charg­ingAVERAGEMEDIAN
Fuel Time Dura­tion (hours)8.3 hours
Trip Dis­tance (mi)151.7 mi
Total Bat­tery Charged (%)62%
Fuel Vol­ume (kWh)43.4 kWh
Miles Gained (mi)164 mi
Total Cost ($)$6.60
Cost per kWh ($/kWh)$0.15
Charge Rate (kW)5.22
Charge Effi­cien­cy (mi/hour)19.7 mi/h
Charge Effi­cien­cy (%/hour)7.5 %/h
Num­ber of Charge Ses­sions2

EVgo

  • Found­ed Octo­ber 2010; HQ Los Ange­les, CA
  • DC Fast Charg­er
  • Acquired the com­pa­ny behind PlugShare July 2021
  • Part­nered with GM in 2022
  • Part­nered with Ama­zon 2023
EVgoAVERAGEMEDIAN
Fuel Time Dura­tion (hours)0.5 hours
Trip Dis­tance (mi)126.7 mi
Total Bat­tery Charged (%)34%
Fuel Vol­ume (kWh)23.7 kWh
Miles Gained (mi)88 mi
Total Cost ($)$9.10
Cost per kWh ($/kWh)$0.46
Charge Rate (kW)39.73 kW
Charge Effi­cien­cy (mi/hour)141.4 mi/h
Charge Effi­cien­cy (%/hour)53.1%/h
Num­ber of Charge Ses­sions4

Home 1 (120V) — extension cord

  • 120V stan­dard out­let plug (actu­al volt­age: ~117V)
  • Exten­sion cord + portable charg­er
  • Exten­sion Cord: Clear Pow­er 50ft 10⁄3 SJTOW extra heavy-duty weath­er resis­tant exten­sion cord
  • Portable Charg­er: ZENCAR lev­el 1 charg­er, 16A, 25ft (has read­out for data)
  • Rough­ly 30 ft from out­let to car charge port
  • Long length of cords cre­ates a lot of elec­tri­cal resis­tance, espe­cial­ly when coiled
  • Cost per kWh is aver­age per month from the elec­tric bill
Home (120V)AVERAGEMEDIAN
Fuel Time Dura­tion (hours)8.7 hours
Trip Dis­tance (mi)61 mi
Total Bat­tery Charged (%)12%
Fuel Vol­ume (kWh)8.2 kWh
Miles Gained (mi)24 mi
Total Cost ($)$1.35
Cost per kWh ($/kWh)$0.15
Charge Rate (kW)0.6 kW
Charge Effi­cien­cy (mi/hour)2.8 mi/h
Charge Effi­cien­cy (%/hour)1.4 %/h
Num­ber of Charge Ses­sions3

Home 2 (120V) — no extension cord

  • 120V stan­dard out­let plug (actu­al volt­age: ~121V)
  • Portable charg­er
  • Portable Charg­er: ZENCAR lev­el 1 charg­er, 16A, 25ft (has read­out for data)
  • Rough­ly 7 ft from out­let to car charge port
  • Long length of cords cre­ates a lot of elec­tri­cal resis­tance, espe­cial­ly when coiled
  • Cost per kWh is aver­age per month from the elec­tric bill
Home (120V)AVERAGEMEDIAN
Fuel Time Dura­tion (hours)1.5 hours
Trip Dis­tance (mi)57 mi
Total Bat­tery Charged (%)2%
Fuel Vol­ume (kWh)1.7 kWh
Miles Gained (mi)4 mi
Total Cost ($)$0.29
Cost per kWh ($/kWh)$0.15
Charge Rate (kW)0.9 kW
Charge Effi­cien­cy (mi/hour)1.9 mi/h
Charge Effi­cien­cy (%/hour)1.3 %/h
Num­ber of Charge Ses­sions4

SemaConnect (now defunct)

  • Found­ed 2008; HQ Bowie, MD
  • Local to the DMV (DC, Mary­land, Vir­ginia) area
  • Acquired by Blink Charg­ing June 2022
  • Mahi Red­dy, CEO of Sema­Con­nect, joined board of direc­tors of Blink Charg­ing
Sema­Con­nectAVERAGEMEDIAN
Fuel Time Dura­tion (hours)7.1 hours7.9 hours
Trip Dis­tance (mi)121.5 mi122.5 mi
Total Bat­tery Charged (%)60%48%
Fuel Vol­ume (kWh)42.5 kWh33.4 kWh
Miles Gained (mi)139 mi123 mi
Total Cost ($)$7.27$7.98
Cost per kWh ($/kWh)$0.16$0.18
Charge Rate (kW)6.17 kW6.03 kW
Charge Effi­cien­cy (mi/hour) 19.3 mi/h18.8 mi/h
Charge Effi­cien­cy (%/hour)8.4 %/h8.4 %/h
Num­ber of Charge Ses­sions2525

Notes

  • First 3 charges were free, then paid
  • Trends more effi­cient­ly as tem­per­a­ture increas­es
  • Once a week charg­ing

Volta Charging

  • Found­ed 2010; HQ Hawaii
  • Free charg­ing, pow­ered by adver­tise­ments
  • Acquired by Shell USA March 2023
Vol­ta Charg­ingAVERAGEMEDIAN
Fuel Time Dura­tion (hours)0.6 hours
Trip Dis­tance (mi)12 mi
Total Bat­tery Charged (%)6%
Fuel Vol­ume (kWh)3.9 kWh
Miles Gained (mi)13 mi
Total Cost ($)$0
Cost per kWh ($/kWh)$0
Charge Rate (kW)6.4 kW
Charge Effi­cien­cy (mi/hour)21.2 mi/h
Charge Effi­cien­cy (%/hour)8.9%/h
Num­ber of Charge Ses­sions4