The Dog Days Cooling Plan

Keep a home cool through the hottest weeks for less: every room read for heat index and dew point, fans kept below the CDC's 90°F limit, one room's air conditioner sized from the ENERGY STAR chart, the forty dog days priced at your own rate, the sun on clock time, and a heat wave card for the fridge

Canicular's free Heat Index Calculator gives a shade reading of the air outside, and the Dog Days Calculator gives a 40-day window. Neither looks inside your home, none of our tools asks what cooling costs, and our sunrise tool speaks solar time, not the clock. Writing this plan we also fixed the heat index itself: it now follows the National Weather Service's full method and never rounds a reading down into a lower caution band. This plan puts them together. In its worked example an apartment's kitchen reads 94.2°F and its bedroom 93°F, both Extreme Caution; the kitchen's 91°F air is past the CDC's line, "Use fans, but only if indoor temperatures are less than 90°F." The 168 sq ft west-facing bedroom needs 6,600 BTU from the ENERGY STAR chart, and ENERGY STAR says an oversized unit "costs more to purchase, wastes energy and does not provide better cooling." At an example 17.5 cents a kWh, a 550 watt room unit is 77 cents a night and $30.80 for the dog days, where a 3,500 watt whole-house system run 12 hours a day is $294.00; the Department of Energy's 78°F instead of 72°F line puts the saving at $17.64 to $52.92. Every figure is computed by code from the site's own tools and is an example for you to replace; the rules are quoted from the NWS, the CDC, ENERGY STAR and the Department of Energy. It is not medical, electrical or installation advice, it says nothing about sun exposure, and its heat wave card carries the CDC's heat stroke signs and "Call 911." Included: seven steps, a room reading sheet, a sizing sheet, a dog days bill sheet, a heat wave card, reference tables and a quickstart, plus a personalised sheet worked from the numbers you entered in the calculator.

Look inside

Two full pages from the plan, exactly as printed. Click either to read it at full size before you decide.

What is in it

• Step 1: every room read at its hottest hour, heat index and dew point by the NWS method, ranked
• Step 2: the CDC's 90°F fan limit, and a fan against an air conditioner by the hour, the night and the season
• Step 3: one room's air conditioner sized from the ENERGY STAR chart and its adjustments, not oversized
• Step 4: a night and the forty dog days priced from the watts on the label and the rate on your bill
• Step 5: the setpoint: 78°F instead of 72°F, the Department of Energy's 6 to 18 percent, and the ceiling fan line
• Step 6: the sunrise tool's solar time converted to clock time for blinds, and when to open windows at night
• Step 7: the heat wave card: where to go, who to check on, never a parked car, and the heat stroke signs with call 911
• Four working pages: room reading sheet, sizing sheet, dog days bill sheet, heat wave card
• Reference tables: heat index by temperature and humidity with NWS bands, the cost of a night by watts and rate, the full ENERGY STAR chart
• A quickstart, and a personalised sheet worked from your own calculator inputs

The plan picks up where the free Heat Index Calculator and Dog Days Calculatorleave off. They give a shade reading of the air outside and a 40-day window; the plan reads every room in your home with the same National Weather Service method, keeps fans to rooms under the CDC's 90°F limit, sizes one room's air conditioner from the ENERGY STAR chart, prices the dog days at your own electricity rate, puts the sun on clock time, and ends with a heat wave card for the fridge. Every figure in it is an example for you to replace. It is not medical, electrical or installation advice; heat stroke is an emergency: call 911.