924Board.org

[wdb]

my electric bill between may and sept runs $200- $240 a month . looking to save money , I had an electrician wire in a hot water heater timmer , to shut the heater off when hot water isnt needed , most of the day and night to try and save .cost me 45 for the timmer and 75 to have installed , literiture says it should pay for itself in 3-5 months .the sticker on the heater says it cost between 40-60 dollars a month to run . I should see 20-30 a month savigs from it , but I'm looking to save more . I was reading up on swamp coolers , and in my climate they're moderatly effective at cooling a house , but using 1 in conjuction with the A/C unit you can see substantial savings . since a/c's dry the air , to between 15-40% humidity ,the swamp cooler works well at those levels , and by using a swamp cooler to pre cool the air , ( 10-20 degrees depending on how often your ac comes on) its cools the house faster and saves money . there is a closet right behind my ac unit , that I could install a swamp cooler into to feed the cool air into the ac , but I'm having trouble finding a swamp cooler to fit , its not the physical size I mean , but rating , there either small room coolers or large mount on the roof units . and I'm not sure if I should spend the money on a 2 stage swamp cooler or if its even worth the extra exspense . anyone using or have any advice about this . looking around I found they were at 1 time made for cars too . so for those who live in hot climates ,it might help the 924's week ac system keep temps down ,or as a spot cooler in the garage ,cost pennies to run . the window mount units for cars look horrid . heres a few links for those interested

http://www.bizrate.com/buy/superfind__cat_id--1,keyword--cooler+swamp,lp--1,mkt_id--11532921,rf--ggl,url_id--2955272.html

http://search.ebay.com/cooler-swamp_W0QQsokeywordredirectZ1QQsonewuserZ1QQxpufuZx

http://www.google.com/search?hl=en&ie=UTF-8&q=evaporative+cooler

http://search.ebay.com/cooler-evaporative_W0QQsofocusZbsQQsbrftogZ1QQxpufuZxQQsonewuserZ1QQfromZR10QQcoactionZcompareQQcopagenumZ1QQcoentrypageZsearch

[kaffine]

You don't want to run a swamp cooler and AC at the same time. The swamp cooler works by evaporating water to lower the air temp this causes the humidity of the incoming air to go up. An AC system works by passing air over a cold coil causing moisture to condense on the coil and lowering the air temp. The 2 would be fighting each other.

Swamp coolers are meant to draw outdoor air past a pad soaked with water as the air goes through the pad it causes water to evaporate. A liquid changing state to a gas asorbs alot of heat. They will lose effiency the high the humidity is because less water will evaporate this is why the draw in fresh air if it recirculated the air the humidity would go up and it would stop cooling.

A house AC system has a normal evap temp of 40 degrees. If the dew point (the temp that the moisture in the air begins to condense) is above 40 degrees it has to condesnse the moisture in the air to lower the dew point. To cause the moisture in the air to condense requires you to remove the same amount of heat from it that it absorbed to change from a liquid to a gas. So running an AC and a swamp cooler wouldn't work to well. The dew point is determined by the relitive humidity and temp. If the dew point was above 40 degrees the air leaving the AC has 100% relitive humidity of course as the air is delivered to the room and it warms up the relitive humidity goes down because warmer air can hold more moisture than colder air.

Not knowing what the climate is where you live I can't say how well a swamp cooler will work for you. I live in Las Vegas humidity is normally below 20% during the summer months and temps can get up to 120 in the shade. Swamp coolers work great here until the temp gets over 100 then they can't cool the air enough.

There are ways of improving AC system effiency but I would have to know what the climate is like in your area. How high the humidity is and daytime and night time temps? What kind of AC system you currently have, does it sit in the sun?
_________________
80 924
80 931

The best desciption of an atom boils down to something unknown is doing we don't know what.
Sir Arthur Eddington

[wdb]

just so its clear , the swamp cooler will be drawing already cool interior air ,my reasoning is that the ac will cool the house to 70 degrees or whatever i set the therm at , when the ac compressor cuts off ,the evap cooler , with the now low humidity , will continue to cool the house until the relative humidity rises to the point where the swamp cooler is no longer effective and the temp starts to rise , delaying the ac from turning on , longer intervals between the ac kicking on saves money , right ? I dont think the few minutes that they are both running at the same time will cause much of a problem . I would be basially using the ac as a dehumidifier/cooler and the swamp cooler will cool the air at 1/5 the cost of the ac and will be providing a large portion of the cooling . and the water that is cooled/drains off the evaporator coil , can be routed to the swamp cooler to replenish it ,and provide cold water for the heat exchanger part of the 2 stage cooler , making the most of the energy it took to cool the water . your right that adding humidity to the air will cause the ac to work harder/less efficiently when its running , but the idea is to minimize its running time by using the swamp cooler .

[kaffine]

Your house AC will be running longer. It has to remove the humidity before it can cool the house.

When your AC shuts off and the swamp cooler turns on it will take the cool dehumidified air cool it while adding humidity until the humidity gets to high and it looses effinecy then the house will start to heat up again and it will be very humid. Then the AC will come on again to bring the house temp back down but before it can effiently lower the house temp it has to lower the humidity all the heat energy that was absorb by the water when it evaporated now has to be absorbed the the AC system as the humidity condenses back into water. Using a swamp cooler like that would delay the AC from coming on but when it did come on it would have to run longer to get the house temp down, also there would be a large swing in the humidity level making it feel uncomfortable.

If you live where the humidity is fairly low and you have a good water supply meaning it wont cause calcuim or other mineral deposits what you could do it put a mister system on the condensor. Set it up so the mist is being pulled in with the air over the condensor coils as the water evaporates it will cool the condensor increasing sub cooling and effiency of the AC system.
_________________
80 924
80 931

The best desciption of an atom boils down to something unknown is doing we don't know what.
Sir Arthur Eddington

[924guy]

the humidity thing is key... ive seen houses and rv's with swamp coolers that were plagued with mold as a result... not pretty... definatly a dry climate only option.. down here in florida, its the last thing you want.. the varieties of nasty molds that can grow are infinate, and it can be a downright dangerous health hazard.. a swamp cooler would turn any house(or vehicle) into a spor factory..
im looking into solar panels for home water heaters and such to save money, but im not yet conviced its viable on a cost to savings level on a small scale...doesnt seem worth the investement unless you go all out and can produce enough energy to sell it back to the power company, and thats a very expensive set up..still working the numbers though...
_________________
Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

[wdb]

thanks for the advice , Kaffine and 924guy . I guess I'll need to find another way .

[8string]

Where do you live? If you're in the Rockies, an evap is a great way to cool your house. I'm in Arizona and we can run ours in April, May, June, part of July, and September. I use the AC when the dewpoint is high in the late summer and when we need heating in winter.

We had a BBQ in Saturday and it was 106 outside, 76 inside, with the swamp on and the patio door open all day.

[wdb]

I'm in texas , today at 5 pm its 91 dgrees and 49% humidity , according to the chart , a swamp cooler could bring ir down to 79 and high humidity , that wouldnt be too bad , but Id prefer around 70-72 . I need to check the humidity earlier in the day tommorro ,to see if it be better for the cooler .

[wdb]

went to a site that says below 80 degrees , high humidity does not add much to the heat index , (hot hot it feels) so if I set the thermastat to 68-70 degrees , even with high humidity , it would not feel uncomfortable , it would feel like a cool rainy day ,and thats fine with me . ok its back to finding or making a swamp cooler . I have a small submersible pump , would need some tubing and pads , maybe some heavy towels would do the trick . hmm

http://www.weatherimages.org/data/heatindex.html

[wdb]

and I think I gonna get/make a swamp cooler for the outside A/C condensor unit , I'd like to run the freon return line through a water bath to extract most of the heat from the refrigerant (water conducts heat 20x's better than air)before it goes to the condensor unit . but that would require a ac tech to come out and splice in an extention onto the return line .

[wdb]

those using coolers , did you know about zinc anodes preventing bacteria and fungus growth . and if so what else do you know that would hepl me with this .

http://www.thinkzincanode.com/index.cfm

[8string]

Trying to use an AC and Swamp together is counter-productive. I wonder how old your AC unit is. Do you have roof vents?

My house was built in 1977. Until two weeks ago, we had a 15 year old MasterCool evap and the original Trane heat pump. The swamp had been slowly rusting out, and I went through real comedy of errors trying to get it replaced this spring. We were basically nursing the old heat pump along this year, when that finally went too. I paid $6200 a month ago, and we got a new industrial MasterCool and a 12 seer heat pump. The swamp is really kicking butt, but we’ll probably have to go to the AC next week.

If your AC unit is as old as mine, it’s so terribly inefficient and worn out that it really has to be replaced. After looking at my electric bill this month, I expect the new units to pay for themselves in two years.

In the interest of being on-topic for the board in some way; the $6200 is on a credit card and I am quite broke now. I didn’t see this coming, and had just dropped a $2k down payment on my BMW. I won’t be able to buy anything for my 924 for a while!

For those still reading, I got a 931 parts car last February for $86. Almost all of the interior and top end of the engine is gone. I’ve started pulling parts off of it to do the 5-bolt update and 5 speed tranny ( the PO said that the 1st gear synchro is shot, we’ll see). There’s also the front and rear glass, some interior bits, and other stuff I need. I’ve already sold some parts for more than $86, so a good score for me. I’ll figure out what to do with a non-rolling shell later on!
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'78 924 - new home in Northern Az.!
'97 Z3 2.8
'07 328i

[wdb]

8string ,you ,Kaffine, and 924 guy could be right and I'm just gunna waste some time and money making 1 (I already have a small pump,old garden hose ,plywood ,silicone and a few tattered towels) , so the expiremental cooler should'nt cost much , maybe $10 for some 1x2's to make a frame. and then I'll know for sure . you see just cause the experts say it cant be done, doesnt mean it cant be done . according to aerodynamicist , bumblebees cant fly , and according to experts in biomechanics , tuna fish dont have enough muscle mass to swimm at 50 miles per hour , but somehow the bees and tuna pull it off .engineers assume everything is a zero sum game , you cant get without giving . alot of rules in science are just theory , but since the formulas work out , we;ll go with it till we know better . no one has ever found a half dinsaur half bird , or a half man half ape , to prove thats what happened ,but its accepted fact . like physicist spending billions to catch nutrinos , they have no electrical charge or physical mass , well whats there , scratch scratch , are you sure ,how do you know ,ever see 1 ,can they prove it , no , but the formulas work out . kinda like cfc's depletting the ozone , they cant reproduce it in the lab or prove thats whats happening , but its accepted fact . same thing with retro viruses and A.I.D.S. they believe its the cause , but 20 years and they have yet to infect 1 animal with aids , not even blood from dying aids patients will make an animal sick or infected , but swiiss doctors got rats to test positive by injecting a rat with his own immune cells , that where extracted a few days earlier . dont believe everything you hear , trust but varify .

[wdb]

AAAARRRRRRGGGGG !!! my electric bill for last month came in the mail today . $996 bill says I used 6096 kwh AND theres a transfer of $330 from a bill they say I didnt pay in march 2003 , have you people lost your dam mind . checked the meter aainst there reading 3 day ago , its running at almost $30 a say , yeeeeooowww .think my AC is causing it , the return line is burning hot . damm , now I have to go argue with the rental agency to pay the dam bill . shoot me now .

[Sleykin]

Are you trying to cool an aircraft hangar with the doors open??
Don't mess with old towels. BTDT. Spring for the real excelsior stuff. Airflow is the key to evaporative cooling. If you got one of those coolmister hoses like they use to cool patios etc and ran it around the condenser it would significantly increase the efficency of your A/C. If you had a well you could use the cold water from the well and circulate it through a car radiator and back to the well. Put the radiator in the plenum and it would do some real cooling for you.
The thermodynamics just don't work for running a swamp cooler in a closed room. I used them for a couple years here in Medford OR. It is after 10 PM and it is 86* and 33% RH now. They work ok here with the low humidity .. normally in the 20's on hot days. The drawbacks are the wind tunnel effect ya have to maintain to get the air temp down and everything is wet. You have to have the windows open and blow the air thrugh the house for it to work.
_________________
Glenn Neff
Medford, OR
87' 924S