Humvee A/C options besides Red Dot ?

[JoeJrTheBarber]

Was looking around the innerweb on possible options to add some sort of A/C to my M998 without going the compressor / Red Dot route.
Not looking to have to wear a sweater in the middle of summer cause the truck gets so cold route, just something that might knock down the inside temp abit on those random hot Chicago days.

I started down a rabbit hole of Semiconductor electric cooling modules that they offer for things like dog houses and large a/v equipment racks.

All seem to be 12volt (which isn't a issue to wire in) but most have a huge power draw upwards of 60watts. Was thinking you run say one under each rear seat (vented properly of course) and one under the drivers and passenger side dash and with a well insulated cabin they might do the job, but with 4 units running that's a 240 watt draw on the system !

Ideas / Thoughts / Thread bashing ?

 

[EladB]

Have you ever played around with a thermo-electric device? I have. They're pretty cool (so to speak). Actually they're cool on one side, and hot on the other. You run current through them, and they basically "pump" heat from one surface to the other. Reverse the current flow and your cooler becomes a heater.

I met a guy in North KC one time years ago who made a cooling system for military helos using them. They do amazing things, but yes, they do suck up a lot of current doing it. And remember, there is no free lunch. While you're blowing cool air into the vehicle, you'll have to be blowing the hot air off of the back side. Lots of it. You'll need some way to exhaust large volumes of hot air outside the vehicle, or use an air-to-water heat exchange of some sort. Maybe you could bolt them to the floor or something, I don't know... but you're going to have to extract a lot of heat from them. Figure out that part (and the power wiring, of course), and maybe it will work. I think it's going to take a few pretty big modules to give you any real benefit, though.

I had a quick look at Ferrotec's larger modules -- many are rated for 33-34 V operation at 10-16 A. Dunno how many it would take to cool the interior of a leaky, drafty HMMWV.

 

[riderdan]

Peltier cooling has been around a long time, but one significant problem (as EladB mentioned) is that the thermocouple sandwich is (almost) heat neutral. So for one side to get three degrees cooler, the other has to get three degrees warmer. Aside from the need to exhaust the warm air and the high current consumption, they are also expensive. That's the main reason you don't see peltier cooling used more often--the cost effectiveness isn't there. By the time you have enough thermocouples to create the same amount of cooling as the typical vapor/compression system, you'll have spent a lot more money. Another downside is that the amount of current they draw is proportional to the temperature differential between the two sides. So for a minor temp difference (say 10 degrees, +5 on ones side -5 on the other) it might take 50 watts. To get a 20 degree difference (+10 and -10) might take 100 watts. And you need a pretty steep temperature difference for it to make a difference in cooling.

The significant advantage is that they have no moving parts. Also, unlike conventional AC they can't leak.

 

[JoeJrTheBarber]

All good info, thanks guys ! Besides the above I have also been looking into a/c systems intended for golf carts and such but all seem to have a "ice box" for better words that needs to be filled with ice in order for the system to blow cold air. I don't see this being a practical way of cooling off our trucks as whichever way I learn towards should be available at a instant, and not with a stop to the local gas station for a bag of ice.

Someone did mention something about a system that use to a/c port-a-potties but I cant seem to find anything online about these systems. Anyone ?

 

[Action]

fan blows air in, cold air blows out tube....



why not just put an OEM system in?

 

[JoeJrTheBarber]

why not just put an OEM system in?

That's the last resort, just looking at / exploring options / seeing what others might have done and had success with.
Thought that's what this forum was all about ?

 

[tage]

I've seen some innovative ways the oem system has been put in....

Anyways I like the cooler idea.

 

[Action]

That's the last resort, just looking at / exploring options / seeing what others might have done and had success with.
Thought that's what this forum was all about ?

The Red Dot is not OEM. There are 2 other versions that are.

Search epay for "under dash a/c 24v" for universal fit boxes.

 

[Postman515]

Red Dot is most economical. The oem under dash setup with fender condensors will cost you around 10k