Swamp Cooler

Hi,

We are in Walnut Creek, and still have our original swamp cooler. It works wonderfully on all but the hottest days (even then it still drops the temperature at least 20 degrees, but when it's 113 outsite, well that's still 93 inside.) I love it, and would replace it with another in a heartbeat.

We do have a smaller model (1300 sq ft) and we have a foam roof, which keeps the house pretty cool anyway.

Last year I did do a quick google search on "evaporative coolers" -- the industry name for swamp coolers, and found quite a few reasonably priced coolers, many of them completely solar powered. That would be the first thing I would look into if we needed to replace ours.

Best,

John Dark

A swamp cooler works worst when you need it the most. They are a big box with a water pump that trickles water over large fibrous pads. A big fan pulls outside air through the pads. Evaporation of this water lowers the temperature of the air, as this more humid volume of air all goes into your house. When the outside air is very dry, the cooling can be pretty dramatic. These are a big deal in Arizona, where the air is very dry. The reason they aren't more popular has to do with why they are called 'Evaporative Coolers'. If the air already has a fair amount of moisture content, there is little evaporation, or cooling, just air movement. We all know what humidity does to comfort level. In areas of the house away from the cool discharge, the air is damper and comfort level is decreased.
Since John Dark has a foam roof, his cooling requirements are a fraction of a house with a big 'heat sink' on the roof. A small window air conditioner would actually make a difference in his house, as it gradually de-humidified the air.

You may also want to check out mini-splilt ductless air conditioners. There were a lot of discussions about them last summer, so you should be able to find them by using the search function.

We installed one last year (2-room verson) and it is been terrific. Far better than a window AC and close, but not quite the same as central air. During last summer's heatwave, in the eveninig when the MBR would have been 85 degrees, I kept it a comfortable 68. In the heat of the day, when it was 100+, I kept it at 72.

We, and several of our neighbors have the Samsung model. We purchased ours in the heat pump version which provides a back-up heating system should we ever need it. A google search under "samsung + mini-split" should turn up pictures and specs for you.

Cathye

I should add that the most dramatic difference came when we replaced our Tar and Gravel roof with a foam one. By our estimates, it made a 10+ degree difference in the summer. But with my inability to handle heat well, and hubby's working evenings and not letting me open up the house at night when he is away, the AC gave us that extra cooling that we needed.

Cathye

With all due respect, Randy, I think your response might have mixed two seperate issues. The original posting requested information on how Swamp Coolers work with "East Bay heat", and in short, they work great. Your response regarding humidity may be appropriate for Palo Alto or another penninsula location that may retain humidity from the bay, but in Walnut Creek, when it's hot, it's dry, almost unconditionally.

Regardless, I agree that moving to a foam roof from a tar and gravel can reduce the average temperature by at least 10 degrees, which seemed to me to be your main point. Nonetheless, we see no need for air conditioning in my house. If you're interested in the specifics of my location, I'm happy to extend an invitation.

Just one question John. When you extend an invitation, does that include Lunch? I agree with you regarding air conditioning an Eichler. After you put the insulation on the outside surface, it's no longer a 'hot topic'. Many people decide not to air condition after getting a foam roof.
However, if someone is considering installing equipment to cool their home, my personal preference would be air conditioning. You have a lot more control over what is going on. The newer equipment is much more economical to use. There is very little maintenance. The return on investment is better. When you get home on a hot evening and only spend a few cents to have your mini-split cool part of the house, you feel like you made a smart choice.

The evaporative cooler discussion could not have happened at a more opportune time given the 75+ temperaturs in walnut creek we saw recently! I have had the burning question of "will evaporative cooling handle <100 degrees temperatures" for quite a while. I understand that 106+ is likely going to be a bit uncomfortable but those are likely less than 10d per year occurrance.

It sounds like this is the most efficient way to proceed (will likely be replacing our roof this summer)! It sounds like it is dry enough in wc when it is hot to be able to get away with this method. I say get away because evaporative cooling is a fraction of the cost in installation and monthly bills. No doubt that refrigerated cooling is supperior but with this comes a superior price and 3-4 times the electricity.

Has anyone found any good resources of 2 stage evaportive coolers or local contractors? I have been looking around but there seems to be a big lack in this area. I'd much rather spend on this method which appears to be slightly less costwise than refrigerated but considerably more efficient than single stage evaporative coolers (40-45 degree drops are not unheard of). Also, there are no plans to have more than 2-3 pentrations for cooling so was wondering if anyone could comment on a similar installation?

I had a 2-stage evaporative cooler in my previous home in San Anselmo (Marin County.) Having lived in Davis and grown up in Contra Costa County I can report that these coolers are great. They would really work well in Walnut Creek and Concord - even in San Rafael.

The benefit in Marin is that the cooler would also function as a whoe house fan at night. Since it causes positive air pressure in the house you just need to open windows to direct the cooled fresh air. We did not have any pressure relief dampers. Just used the windows.

Our cooler was a "Smart Cool" - it was a product developed by the Davis Energy Group and CoolTech. http://oikos.com/esb/52/smartcool.html for more info. It worked great in a wall mount situation. Even in Marin additional humidity from the cooler was not a problem.

More info available at :

http://www.davisenergy.com/
http://www.toolbase.org/tertiaryT.asp?DocumentID=2102&CategoryID=1435
http://www.adobeair.com/index.html

And don't forget about PG&E rebates!
http://www.pge.com/res/rebates/whole_house/evap_coolers/index.html

A two-stage swamp cooler pre-cools the air through a cooled heat exchanger, then pulls the air through the pads for further cooling. Lowering the temperature of the air diminishes the warm air's ability to hold moisture. I've had 18 swamp coolers since 1987 on some industrial property in Arizona. Six two-stage MasterCool units have gone 12 years with only normal maintenance. The water is hard in Lake Havasu, which eats the pads and causes build-up in the pans. Our water is great around here. These coolers work well, and inexpensively in Arizona. When the humidity goes up a little, they don't work nearly as well. I asked a swamp cooler service company, that I know well, which brands were the best and was told MasterCool and AeroCool. MasterCool is one of the few two-stage models. Swamp coolers are not complicated and are somewhat similar from brand to brand. Check pricing on-line. You might ask some local experts what to expect around here when the humidity is over 50-60%. I'm encouraged by the positive comments from some of the posts.