Ancient Egyptian Air Conditioner: Cheops Ships in 2600 BC Egypt

Part of: "What Is a Fly Roof? How To Build a Flying Roof."

Ancient Egyptian Air Conditioner over 4,000 Years Old

Ancient Egyptians of 2600 BC during the Old Kingdom buried 2 ships near the Great Pyramid of Pharaoh Cheops (Khufu) and the ships are known as “Cheops boats,” Cheops ships,” “Khufu ships,” or “solar ships.” The papyriform “Cheops 1” (the only one excavated) shows a cabin that used a fly roof as an air-conditioner by stretching a canvas tarp over the wooden frame and soaking the tarp with water for evaporative cooling--causing the building to sweat so the pharaoh didn't have to:

Ancient Egyptian fly-roof air-conditioner in 2600 BC Egypt (Cheops 1 ship used a wet canvas over the wooden frame to create solar-heat-powered evaporative cooling):

What is a Fly Roof? How To Build a Flying Roof

Part of: "Best Ways To Cool Your Home."

A fly roof (or flying roof) functions as a parasol by blocking sun or other weather without trapping heated air in or against the main structure.

Another function is to vent the interior of the structure, such as a fly roof over industrial "smoke stacks" or the more familiar chimney cap (rain cap) on residential homes. A fly roof is like a chimney cap over the entire house.

The fly roof can use heat convection, solar chimney effects, stack effects, venturi effects, and evaporative cooling (e.g. swamp cooler, a.k.a. desert cooler) as part of an air-conditioning system.

You can get a partial effect by installing radiant barriers under the roof, insulating below the attic floor, and installing attic vents. Imagine if the entire attic walls were vents or screens.

A "double roof" essentially uses a fly roof, sometimes to create ducting between parallel roofs.

A Fly roof can be permanent or temporary (seasonal), rigid or flexible, parallel to an underlying roof or not parallel. You can make the fly roof a “carport” over the house, a tarp suspended over the main structure, or a retractable "window shade."

Here are some fly roofs and a retractable roof:

Ancient Egyptian fly-roof air-conditioner in 2600 BC Egypt (Cheops 1 ship used a wet canvas over the wooden frame to create solar-heat-powered evaporative cooling):

Huge suspension-cable flying roof in Lisbon, Portugal:

Carport-style self-supporting fly roof near Newcastle, Australia:

Large chimney cap in Massachusetts, USA:

Stainless steel chimney cap:

Copper chimney cap:

Masonry chimney cap:

Flying roof framing:

Retractable wheeled roof for an observatory:

Real Power Usage of Appliances (Wattage)

Do not estimate when you can measure.

Guessing can cost you money.

The Kill-A-Watt meter recorded the following results:

• The “1875W” hairdryer used only 1360W on high and 390W on low.
• The toaster-oven and coffee-maker were the next biggest loads, in the neighborhood of a kilowatt (kW), but, like the hairdryer's load, these are short duration uses. Brewing 4 cups (1/3 pot) took 5 minutes and the hot plate measured "zero" watts, so a 2-hour total recorded 0.16kWh.
• The “dorm” mini-cube refrigerator totaled about half a KWh in a day, similar to a constant 22W load but you need 10 times that power capacity because refrigerators are start-stop with a kick-start surge.
• I did not “benchmark” the computers to record their maximum loads. “Normal” was the spike of opening a program or application (browser, word processor) although other active use was sometimes 10-20W less. The desktop does not include the monitor.
• The "40W" fan used only 15W, close to only a third of its rating.
• The radio at maximum volume did not draw enough to register above zero on the meter (using an AC adapter to power the radio).
• The "Actual" numbers in the table are watts (W) observed on the meter, sometimes rounded up a few watts. The meter is less accurate near zero. Anything with an electronic remote control or a non-battery clock is using some power even when "off" (phantom load)--unless you use a "hard off" (for lack of a better term) such as a power-strip switch.

From IHB		Kill	-A-	Watt	Data
(c) 2007
Appliance	Rating (W)	Actual Peak High	Actual Start Boot	Actual Normal	Actual Idle Low	Actual Sleep ”Off”
Coffeemaker drip	1000	820	740	800	0	0
Laptop 150MHz	45	?	31	31	21	1
Laptop 2400MHz	90	?	85	60	25	3
Desktop 900MHz	?	?	60	55	35	2
Fan 4in 1-setting	40	15	NA	15	NA	0
Fan 20in 3-sett	?	170	NA	120	85	0
Hairdryer 2-sett	1875	1360	NA	NA	390	0
Monitor CRT 17in Energy Star	75	75	75	60	NA	0
Radio 2AA cell	?	0	0	0	0	0
Refrigerator 1.7cuft 1/25hp	?	215	215	80	?	0
Toasteroven	?	1150	1150	1100	?	0