واﻟ واﻟ  ﻟﻠ  اﻟ  اﻟﻬ 
Saudi Standards, Metrology and Quality Org. (SAS O) 
 
      
 
 
 
 
 
Final Draft Standard   
 
   
SASO /FDS/31837/2020  
     
Road vehicles – Windshield defrosting and defogging syste ms 
 
 
 
 
 
ICS: 43.040.65 
 
This document is a draft Saudi Standard circulated for comments . It is, therefore, 
subject to alteration and modifi cation and may not be referred to as a Saudi 
Standard until approved by SASO . SASO S TANDAR D SASO/FDS 31837/2020
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Conte nts 
 
 
 
1- Scope and field of application .............................................................. ............................ 2 
 
2- Terms and definitions  .............................................................. ......................................... 2 
 
3- Technical requirements  ............................................................... ..................................... 3 
 
 
Bibliography ............................................................... .............................................................. 5 SASO S TANDAR D SASO/FDS 31837/2020
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Road vehicles – Windshield defrosting and defogging sy stems 
 
1- Scope and field of application 
This standard specifies the technical requirements for windshie ld defrosting and defogging 
systems. 
This standard applies to passenger cars, multipurpose passenger  vehicles, trucks, and buses. 
 
2- Terms and definitions 
For the purposes of this standard, the following terms and defi nitions are applied: 
2.1 Passenge r car 
A motor vehicle with motive power, designed for carrying 10 per sons or less including the 
driver and their luggage, except a low-speed vehicle, multipurp ose passenger vehicle, or trailer. 
2.2 Multipurpose passe nger vehicle 
A motor vehicle with motive power, designed to carry 10 persons  or less or goods equivalent 
by weight which is constructed ei ther on a truck chassis or wit h special features for occasional 
off-road operation. Except a low-speed vehicle or trailer 
2.3 Truck 
A motor vehicle with motive power, designed primarily for the t ransportation of property, 
special purpose equipment, or towing a trailer except a trailer . 
2.4 Bus 
A motor vehicle with motive power, designed for carrying more t han 10 persons, except a 
trailer. 
2.5 Defrosting  
Elimination of frost and/or ice  covering the outer glazed surfa ce of the windscreen by the 
operation of the windscreen defrosting and/or windscreen wiping  and washing systems. 
2.6 Defrosted area 
Area of the outer glazed surface of the windscreen having a dry  surface or covered with melted 
or partially melted (wet) frost, excluding any area of the wind screen covered with dry frost. 
2.7 Windscreen defrosting syste m 
Device, or combination of devices, intended by the vehicle manu facturer to eliminate frost or 
ice from the glazed surfaces of the windscreen and thus restore  visibility, together with the 
necessary accessories and controls. 
2.8 Road load 
The power output required to move a given motor vehicle at curb  weight plus 180 kilograms 
on level, clean, dry, smooth portland cement concrete pavement (or other surface with 
equivalent coefficient of surfa ce friction) at a specified spee d through still air at 20 degrees 
Celsius, and standard barometric pressure (101.3 kilopascals) a nd includes driveline friction, 
rolling friction, and air resistance. SASO S TANDAR D SASO/FDS 31837/2020
(1 Follow the standard SAE J903 until the adoption of the Saudi standard.
3 
 3- Technical requirements 
3.1 Passenge r cars 
3.1.1  Each passenger car shall be provided with a windshield defrost ing and defogging system. 
3.1.2   Each windshield defrosting and   defogging system for  passeng er cars, light trucks, 
and multipurpose vehicles with GVW of 4500 kg or less shall mee t the performance 
requirements in accordance with the test procedures specified i n Standard(1)  when tested in 
accordance with 3.1.3. 
Except that “the critical area” specified in Standard(1)  shall be that established as Area C in 
accordance with Saudi Standard SASO 0000 “Road vehicles - Winds hield wiping and washing 
systems“ and the entire windshield” specified in Standard(1) shall be that established as Area A 
in accordance with Saudi Standard   SASO 0000 “Road vehicles - W indshield wiping and 
washing systems“. 
3.1.3 Demonst ration procedure 
When  testing  the  windshield  defrosting  system  for  passen ger  cars  in  accordance  with 
Standard(1), the following shall be excluded: 
3.1.3.1  During the first 5 minutes of the test: 
a) For a passenger car equipped with a heating system other than a heat exchanger type that 
uses the engine's coolant as a means to supply the heat to the heat exchanger, the warm-up 
procedure is that specified by the vehicle's manufacturer for c old weather starting, except that 
connection to a power or heat source external to the vehicle is  not permitted. 
b) For all other passenger cars, the warm-up procedure may be tha t recommended by the 
vehicle's manufacturer for cold weather starting. 3.1.3.2  During  the  last  35 minutes  of the  test  
period (or  the  entire test  period if the 
5-minute warm-up procedure specified in item 3.1.3.1 of this section is not used); 
a) For a passenger car equipped with a heating system other than a heat exchanger type that 
uses the engine's coolant as a means to supply the heat to the heat exchanger, the procedure 
shall be that specified by the vehicle's manufacturer for cold weather starting, except that 
connection to a power or heat source external to the vehicle is  not permitted. 
b) For all other passenger cars, either: 
1- The engine speed shall not exceed 1,500 p.m. in neutral gear; or 
2- The engine speed and load shall not exceed the speed and load at 40 kilometers per hour in 
the manufacturer's recommended gear with road load. 
3.1.3.3  A room air change of 90 times per hour is not required; 
3.1.3.4  The windshield wipers may be us ed during the te st if they are operated without manual 
assist; 
3.1.3.5  One or two windows may be open a total of 25 millimeters; 
3.1.3.6  The defroster blower may be turned on at any time; 
3.1.3.7  The wind velocity is at any le vel from 0 to 3 kilometers per h our; and 
 
  SASO S TANDAR D SASO/FDS 31837/2020
(2 Follow the standard SAE J903 until the adoption of the Saudi standard.
3 
 3.1.3.8  The test chamber temperature and the wind velocity shall be me asured, after the engine 
has been started, at the forwardmost point of the vehicle or a point 914 millimeters from the 
base of the windshield, whichever is farther forward, at a leve l halfway between the top and 
bottom of the windshield on the vehicle centerline. 
 
3.2 Multipurpose vehicles, trucks, and buse s 
3.2.1  Each multipurpose pa ssenger vehicle, truck, and bus shall be p rovided with a windshield 
defrosting and defogging system. 
3.2.2  Each windshield defrosting system for multipurpose passenger vehicles, trucks, and buses 
shall meet the performance requirements in accordance with the test procedures specified in 
Standard(2). SASO S TANDAR D SASO/FDS 31837/2020
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Bibliography  
 
- The main reference: 
[1] 49 Subtitle B-Chapter V-Part 571-Subpart B Section 103 
(FMVSS 571.103)  “Windshield defrosting and defogging systems”. 
 
- Other References: 
[1] ISO 3468:2014 “Passenger cars -- Windscreen defrosting and demisting systems -- Test 
method”.