Saving on A/C Costs
 

I don't know how many of you use your air conditioner during the summer, but in the Southwest you would have to be tough not too. While thinking about swamp coolers, I remembered a technique I saw while watching Living with Ed...:o

Depending on your local climate, the A/C condenser can be aided along with evaporative cooling. Placing water misters along the sides of the condenser will cool the ambient air up to 30F. The cooler the air the condensor receives, the less it has to work to liquify refrigerant.

As water is usually scarce in any areas this would be useful, I'd consider diverting waste water from showers, sinks, etc. to the misters. Just a thought. :)

- LostCause

One thing I'm considering this summer is a simple shade structure for the unit. Ours is on the west side, so it gets full afternoon sun. Some sort of box or shelter to keep the direct sunlight off it should help.

Well, if you have central air, as I do, you can put a small window unit in your bedroom at night and only cool that one room. Also Bedfans (TM) and other fans help: http://www.bedfan.com/

I saw this on Living With Ed once: http://www.coolnsave.com/splash.html

http://youtube.com/watch?v=oAT_Bjp_ByQ

It is Energy Star approved.

Cool
 

Wow, I may consider this device if it works. My A/C costs and consumption are the highest value in the home throughout the year.

It makes sense, and my compressor could use all the help it can get.

Anyone here have one?

RH77

Not yet but I'm going to buy or make one. Thanks for posting that Arminius.

You can do a few things.

1. Tint your windows

2. Cycle your A/C (in combination with #1)

3. Install an underdrive crank pulley on your car that will spin all your accessories slower.

Sorry Johnny grey, we are talking about Homes, not cars.

I've already done something similar with a sprinkler valve, some misters, a 220 rated wal wart and a non leaky hose. Works OK in South louisiana.

I want to do something heat excange related direct to the freon pipes, basically just a wrap around with copper tubing and some solder. I'm planning on recirculating pool water right now, but may be "geothermal" still weighing options.

That's the thing I remembered. :p

The biggest limitation to the technique is your local climate. Evaporative cooling is dependent on the local humidity. If it's hot and humid outside, as I suspect most of the midwest is during the summer, then it will not work very efficiently. The southwest, where it is often hot and dry, allows the latent heat of vaporization of water to absorb energy from the air.

Great ideas about the shade and portable wall unit...I hadn't thought of those. :)

That got me thinking. I know at least one freon tube is routed to my house above ground. It is only insulated with a degraded foam sleeve. Wouldn't the efficiency go up by:

1.) Shading the pipe from direct sunlight?
2.) Increasing the quality and quantity of insulation around the pipe?

If your "geothermal" method works, be sure to post about it. :)

- LostCause

Arminius -

Thanks for the Cool-N-Save stuff. I am going to look into this. I am an *OGRE* when it comes to using AC. What I want to do is close off the kitchen so that it is the only room to be cooled when the heat hits this summer. ... Reading about Cool-N-Save ... Hmmmm, maybe it won't work for window units. I have a 1.5 ton (18000 BTU) AC unit, and Cool-N-Save appears to be designed for a free-standing AC unit.

PaleMelanesian -

Our single AC unit is on the South Side, so I should do the same. Just been a lazy SOM.

...

I've done a lot of research on solar powered swamp coolers, but have never pulled the trigger because it's pricey and I am worried about evaporative pad maintenance. Here is one I have been tempted to try :

Solacool
http://www.partsonsale.com/solacool.html
http://www.partsonsale.com/20FRONT.jpg

google google google ... found some (obsolete?!?!?) prices (sans solar panels I bet) :

Re: Solar A/C Systems Available? - Fri Jun 21, 2002 :eek:way :eek:too :eek:out of date!!!!!!!
http://tech.groups.yahoo.com/group/solar-ac/message/712
Here's another pricesheet that looks similar :

Solacool prices and specifications
http://www.partsonsale.com/solacoolspecs.html

From what I dimly remember, I *think* I would like the 2012 HP because it is 12 volts and requires a 20" wide window.

CarloSW2

Last time I thought about improving A/C efficiency, I looked to passive solar homes for inspiration. Some of them draw intake air through a long conduit underground that serves as an air/ground heat exchanger. (The home uses a solar chimney to draw warm air out of the house passively.) Taking a page from that book, one could run the same kind of duct to the heat exchanger (which would require a shroud) to provide the same kind of benefit as the misters, but without water. Pumping the cool air directly into the home would be the next logical step (and even better) but would be a much more complicated modification when you aren't building new.

Order placed :thumbup:

I showed the Cool-N-Save video to my Wife too, and she said that it "just made sense". It's on its way!

We'll compare bills from last year when we need the A/C...

RH77

Hmm. Hope that thing works OK, because I saw this next to your post:

ouch!

By the way, I just ordered... :o

JK...

It has already been an "unlucky day".

The mower broke -- had to order a part and I thought the A/C unit went down and it just started working again. Dunno why...

Thanks for taking a picture of that post, forever... :p

EDIT: I think Beaker's expression as he sees the number sums it up. MEEP!

You sound a lot like me. My home has 2 central air units, 2 furnaces and 4 seperate zones, each with its own thermostat. That way the heat and air are only on when a particular area is occupied. Even then, I still shut off unused rooms.

Oh yeah, the least anyone can do to hypermile their air condioner is make sure it's always in the shade. :cool:

http://www.fsec.ucf.edu/en/publicati...SEC-PF-302-96/

the earth is a good heat sink. A straight down well 150 ft deep does not need water to sink a lot of heat per hour from a heat pump. And since the fluid going down the pipe is only slightly lighter than the fluid coming up, there is not much lift involved.

There companies out there that just install these loops.
One I have never dealt with but is all over the country is Loop installers: Loopmasters International, Indianapolis, Indiana.

cool, i mean hot.

the wholesale cost of the hard parts for a 3 ton geothermal heat pump is about 2 times the retail cost of a 3 ton air to air. or about $8000.

Yeah, but I noticed that in the video he spoke of a "cool zone" or something like that. My impression wasn't that it had so much to do with evaporation as the difference in the water temperature. In most places the water coming out of the ground is pretty cold. If it's 90 degrees outside and the water is 50 degrees (ok, I live in Wisconsin), that would be part of the equation.

Would it be anyway beneficial to use a small wind power turbine to recoup some of the energy. Since its blowing anyways why not harness some of the wind?????

Good question. I've read a little about micro turbines, but I haven't seen too many outside of China.

I'd imagine that adding a turbine will lower the fan's CFM (efficiency), negating any gains. It's the equivalent of sticking a generator on a motor to build a perpetual motion machine. You might be able to recoup a small gain, though.

Rather, I would clean the condensor grille pristinely to help increase the fan's efficiency.

- LostCause

I was thinking that too. However, there must be a safe distance at which to place something....hence the micro turbine idea. Not that it would power the AC, but that it would capture some energy. The miro turbines I've seen can generate electricity at wind speeds of 2 mph (I think).

Hey, I found the micro turbines. http://www.inhabitat.com/2007/03/21/...ze-big-impact/

Not a major breakthrough, but still interesting.

Installed. I'll see how it goes when it warms up a bit here.

http://i160.photobucket.com/albums/t182/zpiloto/AC.jpg

Let me know how the cool-n-save does. I'm a little weary because of the high humidity here.

It's suppose to work in humidity. Here's a link to the study.

Nice, Lazarus! That looks like a big unit, too.

We haven't really had to use the air yet -- too rainy and colder than average. I'll compare bills from last year and see if there's any savings once things get going. We may set the temp higher this year, which may skew the results a bit.

I know that once it gets up to 90+ it would run continuously in the afternoon/evening. That may be the true test...

RH77

Cool N Save Arrives
 

The Cool-N-Save system came today, so I hooked it up. (I probably won't need it for a while -- temps have been cooler than average).

http://pic16.picturetrail.com/VOL698.../317399982.jpg

I used zip ties to keep the lines in place.

A few concerns:

• It's often windy on that side of the house
• I could use a 4th nozzle (parts are there except for the line and head -- the kit included a "T" and spare nozzle)
• The filter's washer/grommet didn't seal:

http://pic16.picturetrail.com/VOL698.../317399981.jpg

...so I omitted it. If the nozzles get clogged, I can soak them in a solution. I may write the company and perhaps get another line/head for the back side and mention the filter. It just wouldn't seal.

Since it's under high pressure, it just leaked with the poor seal. The intake line was trimmed, so I have spare length to split it up.

Otherwise, it's misting and hopefully cooling things down. We'll see...

RH77

RH77 -

Thanks for the update. What the heck is the "paddle thingy" in the middle? I couldn't figure it out from the website. Is it a sensor for turning the misters on and off?

CarloSW2

Yup, that's what it does. The photo shows it in "On" mode -- where the fan blows upward and engages the mist. As it shuts down, the paddle lays flat and closes the valves.

I need a Y-splitter if I use the hose -- easy fix. Maybe the splitter will have a higher quality thread and gasket seal surface for the filter.

We get lime scale, etc -- which probably shouldn't be going into the A/C unit, as I think about. The filter probably should go on there somehow...

RH77

It's cool to see some of you guys were willing to be the guinea pigs of the forum...:p

I wonder what kind of deposits the misters will leave on the condensor coils. Like RH77 says, hard water will probably leave behind mineral deposits that could clog the fins. I've read that even with a polyphosphate filter, a white residue can form. In any case, if it gets to bad it will probably be easy to periodically clean it off with CLR.

Being a cheapass, I've been looking over the internet trying to piece a similar device together. Even generic misters are pretty expensive...:o

Can't wait to hear some results. :)

- LostCause

Remember that vinegar is a natural descaler (5% acidic), and it's cheap.

Works for the coffee maker -- why not the A/C :p

At any rate, I'll monitor any build-up and take photos as needed.

I have a question for anyone familiar with heating and air...

The A/C engages the blower fan at a slower speed than the heat. I found this out through the thermostat, which has an "Auto" setting for heat or air. I turned the blower into the "On" position and noted that the speed slowed for the A/C compressor. After 5-minutes of compressor shutdown, the blower speed went back up to full revs.

The system constantly runs in the hot Summer months. Would it be better to resolve the speed issue and run it on full -- or is it like a car, where cooler air can be felt without the use of excess fan speed??? :confused:

RH77

Any thoughts on filling the filter( shown at the faucet) with vinegar to keep the hard water at bay? I imagine if you filled it once a month with as little as the mister put out it work work well with the timing change of the inside filter.

That's a thought. Since it's a 5-micron filter, I wonder if the acidic properties of vinegar would break-down the filter medium?

Maybe at every other mowing, stop at the unit and spray a vinegar solution onto the fins?

RH77

I would spray the vinegar on the unit when it is not running. I've noticed that it works great on widows that have been exposed to the sprinkler. Put a little on and it's clear as glass when you wipe it off.