CLTD Correction factors for latitude and months

From ASHRAE (1989), with permission

Latitude

Month

N

NE / NW

E / W

SE / SW

S

HOR

0

Dec

-3

-5

-2

3

9

-1

Jan/Nov

-3

-4

-1

2

7

-1

Feb/Oct

-3

-2

-1

0

0

0

Mar/Sep

-3

1

-1

-3

-8

0

Apr/Aug

5

3

-2

-6

-8

-2

May/Jul

10

5

-3

-8

-8

-4

Jun

12

5

-3

-9

-8

-5

8

Dec

-4

-6

-3

4

12

-5

Jan/Nov

-3

-6

-2

3

10

-4

Feb/Oct

-3

-3

-1

1

4

-1

Mar/Sep

-3

-1

-1

-2

-4

0

Apr/Aug

2

2

-1

-5

-7

-1

May/Jul

7

4

-2

-7

-7

-2

Jun

9

4

-2

-8

-7

-2

16

Dec

-4

-8

-4

4

13

-9

Jan/Nov

-4

-7

-4

4

12

-7

Feb/Oct

-3

-5

-2

2

7

-4

Mar/Sep

-3

-2

-1

0

0

-1

Apr/Aug

-1

-1

-1

-3

-6

0

May/Jul

4

3

-1

-5

-7

0

Jun

6

4

-1

-6

0

-7

Latitude

Month

N

NE / NW

E / W

SE / SW

S

HOR

24

Dec

-5

-9

-7

3

13

-13

Jan/Nov

-4

-8

-6

9

13

-11

Feb/Oct

-4

-6

-3

3

10

-7

Mar/Sep

-3

-3

-1

1

4

-3

Apr/Aug

-2

0

-1

-1

-3

0

May/Jul

1

2

0

-3

-6

1

Jun

3

3

0

-4

-6

1

32

Dec

-5

-10

-8

2

12

-17

Jan/Nov

-5

-9

-8

-4

9

12

Feb/Oct

-4

-7

-4

4

11

-10

Mar/Sep

-3

-4

-2

3

7

-5

Apr/Aug

-2

-1

0

0

1

-1

May/Jul

1

1

0

-1

-3

1

Jun

1

2

0

-2

-4

2

40

Dec

-6

-10

-10

0

10

-21

Jan/Nov

-5

-10

-9

1

11

-19

Feb/Oct

-5

-8

-6

3

12

-14

Mar/Sep

-4

-5

-3

4

10

-8

Apr/Aug

-2

-2

0

2

4

-3

May/Jul

0

0

0

0

1

1

Jun

1

1

1

0

-1

2

Latitude

Month

N

NE / NW

E / W

SE / SW

S

HOR

48

Dec

-6

-11

-13

-3

6

-25

Jan/Nov

-6

-11

-11

-1

8

-24

Feb/Oct

-5

-10

-8

1

11

-18

Mar/Sep

-4

-6

-4

4

11

-11

Apr/Aug

-3

-3

-1

4

7

-5

May/Jul

0

0

1

3

4

0

Jun

1

2

2

2

3

2

56

Dec

-7

-12

-16

-9

-3

-28

Jan/Nov

-6

-11

-14

-6

2

-27

Feb/Oct

-6

-10

-10

0

9

-22

Mar/Sep

-5

-7

-5

4

12

-15

Apr/Aug

-3

-4

-1

5

9

-8

May/Jul

0

0

2

5

7

-2

Jun

2

2

3

4

6

1

64

Dec

-7

-12

-17

-16

-12

-30

Jan/Nov

-7

-12

-16

-13

-8

-29

Feb/Oct

-6

-11

-13

-4

4

-26

Mar/Sep

-5

-9

-7

-3

11

-20

Apr/Aug

-3

-4

-1

5

11

-11

May/Jul

1

1

3

6

10

-3

Jun

2

2

4

6

9

0