How to build an inexpensive swamp cooler

How to build an inexpensive, energy efficient swamp cooler instead of buying new.

By Tim Fyock

Updated Jul. 24, 2003

My plans will describe how to build swamp coolers ( evaporative coolers ) small enough to cool a single room and large enough to cool your whole house. Over the past twelve years, my swamp cooler design has cooled a 2000 sf house to an average temperature of 66 degrees using 1/10 the electrical of a conventional air conditioner. The parts cost to build my large swamp cooler was around $40* and $12* for my small swamp cooler. I estimate that building my large swamp cooler has saved me $400 rather than buying a new swamp cooler and hundreds of dollars in electricity over A/C system. An other advantage to my design is most commercial swamp coolers will only fit a rectangular window opening (12"H X 30"W) but if you have an older home with a rectangular window opening (say 30"H X 12"W) you are out of luck, my swamp cooler design works on both windows sizes. Another advantage is portability, this swamp cooler design is lighter and more compact for easy transportation from site to site (tents, construction sites, campers, and etc.). Since I have found it cheaper and easier to build my own swamp cooler which works as well (or I believe better based on empirical and theoretical results) as a commercial unit, buying a new cooler is never considered.

Empirical data for large SC. 90 F+

Date	Humidity	OutsideTemperature	Inside Temperature	Temp Delta
Jun 30, 2002	15%	93 F	65 F	-28 F
July 02, 2002	09%	94 F	65 F	-29 F
Aug 16, 2002	16%	96 F	65 F	-31 F
July 24, 2003	25%	100 F	69 F	-31 F

FAQ's

How long does it take to build my own cooler?

Build time for a single room swamp cooler is a few hours, a few days (building a platform etc.) for a large swamp cooler suitable to cool a large house.

Can I use this cooler design on a large scale?

Several people have asked if my plans can be used to cool large warehouses or large stores? technically the answer is yes, but finding inexpensive fans large enough for a single or multiple units is out of the realm of most commonly available parts (becoming industrial in grade) and the price goes up quickly. Secondly, as the owner of your own residential property you may basically do as you please in matters of home improvement. But, in commercial work, the rules are commonly more strict and it may be easier to buy an industrial commercial unit. Factories commonly use room sized evaporative coolers (technically correct name for swamp coolers) as a cost effective cooling solution so I do not see why my design could not be adapted.

Can this cooler design run without electricity?

Other people have asked if this design can be used without electricity. The answer is yes, my design lends itself nicely to this application compared to commercial units. These types of designs are explained using several techniques in the appendix.

What skills are required to build a cooler?

Minimum skills needed to build your own swamp cooler is the about the same if you bought a commercial swamp cooler and installed and repaired it yourself. This is not a project for people who cannot use common hand/power tools or cannot electrically install a major home appliance. Minimum Power tools required are a jigsaw and a drill. Hand tools needed are nothing more than what most people use in home repair.

Why should I use a swamp cooler rather than an air conditioner?

This is rather a moot question considering that cooling my house with forced air A/C, the last time I checked at Home Depot, required I replace my current furnace and install an outdoor heat pump. The cost of this "little" upgrade started at $2500 for the A/C unit and would eventually go a lot higher. If you are reading this, chances are you are sitting in a 90+ degree house, do not have an A/C installed, and can't afford to install one. I was in such a condition when I designed my swamp cooler over twelve years ago. As seen earlier, swamp coolers (SC) use 1/10 the power and are easier and less costly to maintain. A/C can remove humidity from the air. In a dry climate this is unwanted. SCs add humidity. A/C is a closed system, indoor air pollution could be increased. SCs constantly replace indoor air. SCs do not require ducting to distribute.

Please contact The Future Company For a fax/mail order form. instructions and plans are $19.98 + S/H.

*some parts bought used, your prices may vary.