air conditioner pre cooler

[haklesup]

An attic fan or vent are of similar efficiency providing they move equivelent amounts of air using similar amounts of electricity. What varies is the flow pattern of the air within the attic.

An attic fan will provide significant cooling in most cases providing you do not use it at the same time as the A/C of course.

A solar powerd whole house fan seems like a good idea until it poops out at 9PM and its still 90F outside and 140F in the attic. My thermostat activated vent fan runs for hours after sundown on stored heat. A solar assisted fan would be closer to ideal or one solar and one electric which hand off the wind at the right time.

When I made my earlier comment about cooling the hot coil, I was ignoring what effect that would have to cause the energy savings. Upon further thought I now revise my comment:

Removing additional heat from the hot coil will result in less power to cool a room because the cold coil will get colder. This is because the compressor and refrigerant will work as they always did, with the pressure at the output of the compressor and the same pressure differential in the expansion valve resulting in the same delta T at that crucial cooling step. Since hot side is cooler, the cold side can be cooler thus allowing the cold coil to remove more heat faster from the room and thus run less for the same set-point.

I didn't mean to imply you were wrong MrAl, but You must see I am a stickler for complete details. I was just trying to fill in the blanks

All the conventional wisdom about not altering the air flow in an AC system mainly applies to the cold side coil where air flow and pressure are critical to distributing the cooling to all rooms evenly and efficiently. Speeding or slowing the air with the wrong filter can cause all sorts of (comfort) problems. The hot side however has no such limitations. It's overengineered to remove as much heat as possible under worse case hot days (of which most days are not). So improving its ability to remove heat by increasing airflow or air temp or the air's heat capacity (wet air holds more heat) can only help (so long as those efforts don't cost more energy that you save). The only reason I can see it wasn't done in the first place is so that manufacturers can make a standard product with high reliability and not overspend on materials in that part of the unit.

[Chris Smith]

Again, water on the coil is good only if the coil is not doing its job.

In almost all attic situations I have found that only one fan is attached?

So how can you empty a cup, up side down, unless you apply a suction,... and just how efficient it that?

Place one fan on one side of the roof blowing in the wind, and pace a second fan at the opposite end sucking out the hot wind, and you will then have an attic cooler at minimal energy usage.

Trying to suck out hot air from a closed system [a sealed attic with one fan] is a waste of time.

Cross flow costing just a few watts can expel all of the air from the attic for just pennies each hour.

[frhrwa]

I have the attic fans also.. but, attics aren't sealed. If they were, your right, it wouldn't work... most all roof designs implement bird vents or gable vents or both.. mine has both.. the bird vents work great because they are down under the eaves in the shade (unfortunate that shade in Las Vegas is a mere 115 degrees, guess that's better than 119 in the sun.. but, the moving air does cool the attic because its usually well over 140, probably near 160... so... that cool 115 is a lot cooler than what's up there..

[Smoke_Maker]

frhrwa, I live in lost wages also. I have tried several different things to keep the house cool. One of the things I tried was a swamp cooler for most days and then turned on the A/C for the hottest days ( swamp cooler in the shade was a key). In the end I went back to using the A/C and fixed the house, hole house long awnings on the east and west side of the house, shade on the south side of the house, increased thermal mass inside the house, blown insulation in the attic, new double pane windows throughout, a new high SER rating A/C is next.

I think that the A/C builders have thought of almost everything to get a high SER rating.

[frhrwa]

well, opinions as they may... I believe we'd still be using rotary dial telephones if Ma Bell had her way and hadn't been challenged by a little competition... I believe we'd have those 100mpg motors in cars if the "big oil" lobbyists didn't pay someone off.. and... if FREUS didn't have the patent on this design, I believe TRANE, and the rest would be selling it also.. I've been in LV since 1947, we grew up with swamp coolers. Thats all we needed back before all of the swimming pools, lakes, fountains, etc were built all over the valley.. that swamp cooler kept our house cold!.. My highschool buddy has been pre-cooling all of his a/c units (he has rentals, his folks house, and his) for over 20 years with great luck and proven efficiency. I placed this in the forum to see or hear what ideas everyone on here would present. You never know, someone might have come up with a little twist on this and improve the method?, so.... At any rate, I'm glad to say for the non-believers, "IT WORKS"... there is even a company that sells pre-cooler panels that you install on the outside of your condenser fan coils to do this.

[petterz88]

yeah your actually right with this, anyway thanks for all those advice and tips here..


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Everpure Filters

[MrAl]

[quote="petterz88"]yeah your actually right with this, anyway thanks for all those advice and tips here..


Well i hope so after some 7 years later (chuckle)

Or could it be your just doing a little spamming?

[Waiting patiently for reply]

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[reloadron]

I think it's a bot running a setup. Check the IP?

Ron

[chribec2]

I lived in Barstow, Calif. from 1973 to 1987. Swamp cooler worked great after I made some changes. The cooler
was roof mounted so I removed the ceiling grating at the end of the hallway, opened the attic inside trap door
at the other end of the hallway and cut a large opening in the attic portion of the wall separating the house from
the garage. The garage had a series of vents so the air had some way of getting back outside. Moving the attic
air around made a big difference in the house temp. 85 degrees inside the house - 114 degrees outside. It
amazed me how many people that had evaporative coolers didn't know they had to keep a window or door open
so that the air being pumped into the house had a way to get out of the house. Had some interesting times out
there.

Phil Potter.

[frhrwa]

well, I know everyone is waiting with baited breath for the results of last years test.. I insulated the entire attic and garage attic with that foil insulation, I have two attic fans, one at each end of the house.. these both blow out.. they draw that cooler air in from the soffet vents (like was mentioned above, the shady air under the soffet is much cooler, if you can call it that, than the sunny parts of the surrounding house).. the evaporative cooler is on a relay so it only comes on when the a/c comes on.. it works very well, cools the condenser quite a bit.. I think that's it basically for what I've done, now the results.. I've cut my power bill almost 45% in the summer.. water bill was negligeable.. since I no longer have a lawn, its desert landscape (rock).. so, it actually went down.. I looked at the solar attic fans, but, most folks don't realize that even tho the sun isn't up, its still well over a 100degrees at midnight.. that killed that idea.. I'm very happy with the results and would be really interested in hearing more from you guys, especially if someone comes up with an updated version, or a new idea.. that's how it all begins.. "give it to Mikey, he'll eat anything".. thanks for all the views, comments, suggestions, and guidance.. wayne (I'm back up in Washington for this summer, but its still going to be running down there, only the a/c will be set for around 85 or so when my sister comes up for the summer.. the house guest can move it as they desire I suppose..) its cold here, been in the 30's at night, and squeaks into the 50's in the daylight.. snowed last week.. weird weather.. now to figure out cheap heat!

[Bob Scott]

Spam is gone.

[psycho]

Is there a way to lock threads? Maybe threads that have not had any traffic for a month should be locked.

Just a thought.
psycho

[CeaSaR]

Personally I am not for locking threads unless they get way out of hand. I have only seen one
thread on this board get locked. Besides, there have been times when I see things and remember
a thread and bring it up from the past - the SPDIF thread and Stringed Instrument Tuner thread
are 2 examples. I have my own threads that I want to update in the future and would hate to not
be able to do so. My thought would be to give a few more of the "regulars" Moderator status so
that they could help deal with the spam.

I hate spam as much as you, but I hate my freedom being taken away even more.

CeaSaR