OT Window AC, put screen over outer vents?

Speaking generally, about window air conditioner units in the 5,000 to

8,000 BTU range.

Seems to me that much of the problem with slinging water onto the cooling fins is caused by bugs and crud getting into the unit.

Would putting ordinary window screen material over the vents restrict airflow too much?

Thanks.

Reply to
John Doe
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Slinging the condensate water over the condenser coil is intentional. The fan has a ring around the circumference that dips into a pool of the water. The evaporation of the water aids the efficiency of the unit.

Reply to
tom

That's amusing. I figured the most likely misunderstanding would be that I'm promoting the use of the slinger. Some people circumvent it, but that's not what I'm suggesting.

Reply to
John Doe

Dunno how old the message you responded to is , but you didn't answer the OP's question . The answer is that no , screen won't restrict airflow significantly as long as you keep it clean .

--
 Snag
Reply to
Terry Coombs

Probably won't restrict bugs either, they can get pass very small cracks. How about just splaying it with pesticide?

Reply to
edward.ming.lee

It would keep bugs (especially flying bugs like mosquitoes) and airborne crud from getting into it. The only question IMO is whether it would restrict airflow. The last thing I would want to do is make it into a bug trap.

Vacuuming bugs and cried off of the outer screen would be a lot easier than trying to remove it from the inner slats/coils.

Reply to
John Doe

On Fri, 3 Jun 2016 10:49:08 -0000 (UTC), John Doe Gave us:

The only thing you sling is utter stupidity and bullshit.

Reply to
DecadentLinuxUserNumeroUno

On Fri, 3 Jun 2016 08:52:57 -0500, "Terry Coombs" Gave us:

You ain't real bright are ya, boy?

Reply to
DecadentLinuxUserNumeroUno

On Fri, 3 Jun 2016 07:09:59 -0700 (PDT), snipped-for-privacy@gmail.com Gave us:

Yeah, that what a retard like Donald J. Drumpf would do.

Are you always this stupid, or just when you are talking to someone who incorrectly responded to another retard?

You been sniffing pesticide haven't ya, boy?

Reply to
DecadentLinuxUserNumeroUno

Yes, like millions of people do. It will go away in few hours. So what if it get suck into the room? No worst than spaying inside.

Reply to
edward.ming.lee

As I understand it, the critical question is if the compressor might overheat from restricted airflow, and the Internet answer I found was that the cool refrigerant returning from the evaporator was enough for it.

On the other hand an airflow reduction that increases the condensor's temperature will decrease the cooling efficiency.

The air from the A/C in my car is spec'd to be cooler than outside by some amount, as measured with a thermometer in a vent. Maybe that applies to window A/Cs too?

--jsw

Reply to
Jim Wilkins

Almost by definition, a screen *would* turn into a bug trap / crud trap, and restrict the airflow, unless cleaned regularly. The only way a screen can stop things like bugs and bits of flying debris is to block them from entry - which means that they tend to end up pushed against or stuck to the screen wires by the force of the airflow.

A mosquito-grade bug probably doesn't have the strength to fly back away from the screen, against the in-blowing air... so it's likely to die there. Bits of dust and dirt can't fly away at all.

The force which holds things against the screen exists only because the object is blocking part of the airflow... and, thus, obstructing and slowing the airflow.

In order to keep bugs out of the condenser *without* having them build up on the mesh, you'd need to block the bugs where the airflow is low, so that they aren't sucked against the mesh and can fly away. For a given volume of airflow this means that you'd want to maximize the screen area, so that the air velocity through the mesh is minimized.

You wouldn't do that by putting a piece of mesh against the surface of the condenser... rather, you'd build a larger enclosure or "funnel" around the airco inlet, with a large entrance area covered by mesh, funneling down to a smaller exit area that matches the condenser input.

Not the simplest or least-obvious thing to do. Not everybody has an old Klipschorn cabinet sitting around, waiting for a new use :-)

You've got a tradeoff here. Several, actually.

The smaller the screen mesh, and the larger the percentage of the cross-sectional area that are blocked by the screen wires, the more efficient the crud-trapping is going to be - smaller mesh openings allow the blocking of smaller particles. However, this also means more obstruction to the airflow (even when the screen is clean) and thus reduced condenser efficiency and/or higher electrical power needed to maintain the same level of airflow over the cooling fins or coils. The more efficient the particle-stoppage, the more frequently you'll need to clean the mesh.

Even with a small mesh, you'll still get some amount of stuff passing through the screen (smaller particles) and some of these may end up on the fins/coils.

Larger, more open meshes will obstruct the airflow less, and probably won't require cleaning as often, but won't be as efficient in stopping bugs and so forth.

Another approach might be seeing if you could make the condenser easier to clean. Something like LPS "dry film silicone lubricant", Super-Lube Dri-Film, a mold-release spray, or something like that might be useful... a thin, dry layer of silicon or Teflon or wax which would make the condenser surface slippery, would not attract dust, and would discourage debris and bug parts from sticking to the fins/coils.

Reply to
Dave Platt

On Fri, 3 Jun 2016 11:34:02 -0700, snipped-for-privacy@coop.radagast.org (Dave Platt) Gave us:

The exterior "condenser" of a window AC unit blows OUT as it is exchanging the HEAT of the HEATED coolant with the cooler outside ambient air. The INSIDE "evaporator" unit exchanges INTERIOR warm air, cools it and that is what heats the coolant that then gets passed through the EXTERIOR heat exchanger "condenser".

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Reply to
DecadentLinuxUserNumeroUno

Depends on the size of your local bugs.

I had a similar problem with cooling intake fans on various radios and computahs. Dust and dirt would collect on the air intake screen and eventually clog. Cleaning was difficult. So, I used 4 layers of rather widely spaced wire screening on top of each other. The mesh size, with all 4 screens in place, was small enough to trap the small crud and bugs, usually all on the outer screen. It was easy enough to remove, clean, and replace just the outer screen, leaving everything else running normally. However, you won't have this problem because the external exhaust from a window air conditioner blows air out of the box, not into the box. Also, the cooling fins and coils are on the inside of the window air conditioner, not the outside. Water on the cooling fins should just leak out the drain hose on the outside. If there's nothing coming out, the hose might be clogged with bugs, or whatever.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

Even if it doesn't clog, most screens cut half the airflow, or more. Not a good thing for an AC unit.

Reply to
krw

Air is sucked into the box from vents that are on the outside part of the box.

I'm talking about the evaporator coils and fins (where the splasher is), not the cooling coils and fins.

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> Water on the cooling fins should just leak out the drain hose on the  
> outside. If there's nothing coming out, the hose might be clogged with 
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Reply to
John Doe

The cooling coil is the evaporator, the outside coil is the condenser. The evaporator condensate is drained to the exterior in a water channel where i t settles in a pan under the condensor. The formation of condensate represe nts loss of cooling capacity because it represents removal of latent heat f rom the water vapor to make the phase change to liquid without reducing air temperature. It therefore makes sense to regain that capacity by using the water to cool the condenser by the reverse process of converting liquid to vapor by extracting heat from the condenser without requiring an operating temperature increase. Generally the A/C heat exchange and air flow are siz ed at 400CFM/ton, so your little 8000 BTU runs at slightly less than 300 CF M and a 5000 BTU at less than 200 CFM. A window screen filter is not necess ary, the outside portion is going to get dirty and breed slime, leave it, a nd clean it at the end of the season.

Reply to
bloggs.fredbloggs.fred

...that is an oxymoron.

Water vapor condenses on the evaporator coils.

Water evaporates on the condenser coils.

I can accept the terminology, but Yikes!

And breed mosquitoes, and block the airflow, and sling stuff that damages the fragile coil slats.

A lot of people bypass the slinger because their experience is different than yours. I'm looking for a solution.

Reply to
John Doe

Not if you undertstand that the evaporation process is referring to the ref rigernat internal to the evaporator and condensation is referring to the wa ter vapor external to the coil.

The environment is too violent for mosquito survival what with the shallow water pan, high speed slinger and airflow. By far the greatest hazard is gr owing deadly bacteria like legionella. The coil structure is called tube an d fin, those are fins and not slats. Since any objects that get propelled a gainst the coil are thrown there by the airflow, there's not enough force t o damage the coil. The water will eventually rinse any debris lodged in the fins.

Those people don't know what they're doing. In the old days there were mod kits the user could set up to circulate a water curtain in front of the coi l in the airstream "swamp cooler" fashion, but these days a simple slinger ring on the fan blades will do.

Reply to
bloggs.fredbloggs.fred

I'm sure the namers weren't referring to the water, even though the terms "evaporate" and "condense" most frequently refer to water, and water condensing and evaporating has everything to do with an air conditioner.

It's truly weird semantics.

Only when you assume things, like there will never be intervals when the air conditioner is off.

Don't be an asshole. The purpose of language is to communicate. Everybody knows what I was referring to.

Bullshit.

Says you.

Reply to
John Doe

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