Air Ions and Their Relation to Human Comfort

Publisher’s version / Version de l'éditeur:

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la

première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

Paper (National Research Council of Canada. Division of Building Research); no.

DBR-P-677, 1976-03

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.

https://nrc-publications.canada.ca/eng/copyright

NRC Publications Archive Record / Notice des Archives des publications du CNRC : https://nrc-publications.canada.ca/eng/view/object/?id=ff5a10a8-a063-45e8-809e-6f1fbc4e2dfe https://publications-cnrc.canada.ca/fra/voir/objet/?id=ff5a10a8-a063-45e8-809e-6f1fbc4e2dfe

NRC Publications Archive

Archives des publications du CNRC

This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

Air Ions and Their Relation to Human Comfort

no.

677

c. 2

NATIONAL RESEARCH COUNCIL OF CANADA

DIVISION OF BUILDING RESEARCH

AIR IONS

AND THEIR RELATION TO HUMAN COMFORT

C.Y. Shaw and G.T. Tamura

DBR

Paper

No.

677

Ottawa

March

1976

A I R IONS AND THEIR RELATION TO

HUMAN

COMFORT by C.Y. Shaw and G.T. Tamura

ABSTRACT

T h i s p a p e r reviews c u r r e n t knowledge o f a i r i o n s , w i t h emphasis on t h e l e v e l s o f i n d o o r and o u t d o o r i o n c o n c e n t r a t i o n and p o s s i b l e

p h y s i o l o g i c a l e f f e c t s o n human comfort, u s i n g n a t u r a l l y and a r t i f i c i a l l y i o n i z e d a i r . There i s a p p r e c i a b l e e v i d e n c e t h a t f o r some c l i n i c a l t r e a t - ments t h e use of n e g a t i v e i o n s i s b e n e f i c i a l ; b u t t h e r e i s e v i d e n c e a s w e l l t h a t t h e b e n e f i t s f o r normal s u b j e c t s a r e of v e r y l i t t l e o r no

p r a c t i c a l s i g n i f i c a n c e

.

LES IONS DANS L'AIR ET LEUR RELATION AVEC LE COMFORT

HUMAIN

p a r C.Y. Shaw e t G.T. Tamura

Les a u t e u r s examinent les c o n n a i s s a n c e s a c t u e l l e s a u s u j e t d e s i o n s dans l ' a i r , e n i n s i s t a n t s u r l e s n i v e a u x de c o n c e n t r a t i o n d ' i o n s

5

l ' i n t g r i e u r p u i s e n p l e i n a i r e t s u r l e s r 6 p e r c u s s i o n s p h y s i o l o g i q u e s G v e n t u e l l e s q u a n t a u c o n f o r t d e s gens, e n s e f o n d a n t s u r l ' a i r i o n i s 6 n a t u r e l l e m e n t e t a r t i f i c i e l l e m e n t

.

I1 e x i s t e d e s i n d i c a t i o n s a p p r g c i a b l e s que l ' u t i l i s a t i o n d e s i o n s n g g a t i f s e s t s a l u t a i r e dans c e r t a i n s t r a i t e - ments c l i n i q u e s

,

mais d ' a u t r e s i n d i c a t i o n s montrent q u ' i l s o f f r e n t

trss

MEASURING

INSTRUMENT

Measurement of the density of air ions, either positive or

negative, is usually made with an ion counter whose basic component

is a condenser. The ion counter does not count the number of ions

directly but collects and measures the ion current to the condenser,

from which the number of ions is calculated by assuming that each ion

carries a unit charge.

Figure 1 is a schematic of a typical cylindrical

condenser (7).

The inside diameter of the outer cylinder and the

outside diameter of the inner cylinder are

D and d, respectively.

Air is drawn between the two cylinders at an average velocity of u.

If

V is the potential difference between the two cylinders, the

electric intensity E at a point r from the axis is

The time, t, for an ion with a mobility,

w,

to move from the outer

cylinder to the inner cylinder is

The ion is carried along by the airflow in the axial direction with

an

average velocity of u; for it to reach the inner cylinder, the

minimum length of the cylinder should be

Replacing u by the airflow rate gives

Finally, the number of ions per unit volume is

where

N

=

number of ions per unit volume

i

=

ion current

e

=

charge per ion