Canjin iska a kowace awa

**''Canjin iska'<nowiki/>'' a kowace awa**, taƙaitaccen **ACPH** ko **ACH**, ko canjin iska shine yawan lokutan da aka cire jimlar iska a cikin ɗaki ko sarari gaba ɗaya kuma aka maye gurbinsa cikin awa ɗaya. Idan iska a cikin sararin samaniya ko dai iri ɗaya ne ko kuma cikakke, canje-canjen iska a kowace awa shine ma'auni na sau nawa iska a cikin wani sararin samaniya da aka maye gurbin kowane awa. Cikakken iska mai gauraye yana nufin yanayin ka'ida inda iska mai samarwa ta kasance nan take kuma daidai da iska da ta riga ta kasance a cikin sarari, don haka yanayin kamar shekarun iska da kuma yawan gurbataccen abu daidai ne.

A cikin shirye-shiryen rarraba iska da yawa, iska ba daidai ba ne ko kuma cikakke. Gaskiyar kashi na iska na kewaye wanda aka musayar a cikin wani lokaci ya dogara da ingancin iska na kewayen da hanyoyin da aka yi amfani da su don iska. Wadannan tsarin sun fito ne daga tsarin tunani na cikakkiyar motsi, wanda ke cirewa da maye gurbin duk iska a cikin sarari, zuwa gajeren kewayon da ke cikin abin da aka maye gurbin kadan daga cikin iska da ke akwai. Gaskiyar adadin iska da aka canza a cikin yanayin iska mai gauraye zai zama 63.2% bayan awa 1 da 1 ACH. Don cimma matsin lamba, adadin iska mai dawowa (iska da ke barin sararin samaniya) da adadin iska mai samarwa (iska mai shiga sararin samaniya).&nbsp;

## Ma'anar
 
Tushen: 

## Tsarin

### Canjin iska a kowace awa
**A cikin rukunin Imperial:** \quad ACPH = \frac{60Q}{Vol} 

inda:

* *ACPH* = yawan canje-canjen iska a kowace awa; ƙimar da ta fi girma sun dace da ƙarin iska
* *Q* = Girman iska a cikin ƙafafun cubic a minti daya (cfm) 
* Vo*W*">L = Girman sararin samaniya L × W × *H*, a cikin ƙafafun cubic

**A cikin sassan ma'auni** \quad ACPH = \frac{3.6Q}{Vol} 

inda:

* *ACPH* = yawan canje-canjen iska a kowace awa; ƙimar da ta fi girma sun dace da ƙarin iska
* *Q* = Yawan iskar iska a cikin lita a kowace dakika (L / s) 
* Vo*W*">L = Girman sararin samaniya L × W × *H*, a cikin mita cubic

Ga ɗaki da aka ba shi ko girman gini da yawan canje-canjen iska a kowace awa, yawanci ana ƙayyade buƙatun kwararar ƙira a cikin mita cubic a kowace awa yayin amfani da raka'a.

### Yawan iska
Sau da yawa ana nuna ƙimar iska a matsayin ƙimar ƙarar mutum (CFM ga mutum, L / s ga mutum). Canjin tsakanin canjin iska a kowace awa da yawan iska ga kowane mutum kamar haka:

 \quad Rp = \frac{ACPH*D*h}{60} 

inda:

* *R<sub>p</sub>* = ƙimar iska ga kowane mutum (cubic feet per minute (CFM) ga kowane mutum ko cubic meters per minute ga kowane mutum) 
* *ACPH* = Canjin iska a kowace awa
* *D* = Yawan ma'aikata (square feet ga kowane mazaunin ko murabba'in mita ga kowane mazauni) 
* *h* = Tsawon rufin (ƙafafu ko mita) 

Cubic mita daya a minti daya = 16.67 lita / na biyu

## Shawarwarin canjin iska
Sau da yawa ana amfani da canjin iska a matsayin ka'idojin yatsa a cikin ƙirar iska. Koyaya, ba a amfani da su a matsayin ainihin tushen ƙira ko lissafi. Misali, ana lissafin ƙimar iska ta zama bisa ga yankin zama da yawan mazauna. Rashin iska wanda ba na zama ba ya dogara ne akan yankin bene da yawan mazauna, ko ƙididdigar narkewar sanannun gurbataccen abu. Ka'idodin ƙirar asibiti suna amfani da canje-canjen iska a kowace awa. Za'a iya samun sauye-sauyen iska da aka ba da shawarar a cikin ƙa'idodin da suka dace. Binciken da aka yi kwanan nan ya nuna cewa Canjin iska a kowace awa (ACH) kadai bazai zama abin dogaro ba don yin shawarwarin iska. Sabon siginar, *tasiri* Air Changes per Hour (wanda ake kira ACHH ta Mojtaba Zabihi et al.  ), wanda ya haɗa da yawan kwararar da manyan tsarin iska, na iya samar da daidaitattun ma'auni na yadda ake samar da iska da kuma rarraba a cikin ɗaki. Wannan yana da mahimmanci musamman don sarrafa yaduwar cututtukan iska.

## Hanyoyin auna
Canjin iska a kowace awa ma'auni ne da aka nufa don sadarwa da tasirin canjin iska na tsarin iska na sararin samaniya. Tattaunawa game da ma'auni na ASHRAE 62, Ventilation for Acceptable Indoor Air Quality ya haifar da ci gaban hanyar kai tsaye na auna tasirin canjin iska tare da amfani da iskar gas. Gas mai ganowa karamin gas ne wanda aka gano da sauƙi wanda aka gauraya da iska don nazarin tsarin iska. Wannan hanyar kai tsaye tana kwatanta shekarun iska inda mazauna ke numfashi da shekarun iska wanda zai faru idan iska ta sararin samaniya ta haɗu sosai. An tsara hanyar don fahimtar tasirin yanayin iska a cikin sarari, don ganowa ko kauce wa irin waɗannan abubuwan da suka faru kamar tsarin iska na gajeren lokaci, wanda yawancin iska ke tafiya kai tsaye zuwa ga hayaki, kuma ya kasa haɗuwa da iska da ta riga ta kasance.

Akwai hanyoyi guda biyu don amfani da wannan hanyar; dabarar da aka fi amfani da ita, Tracer Gas Decay (mataki-sauka), ya ƙunshi ɗan gajeren fashewar iskar gas da aka yi amfani da ita a cikin sararin samaniya don kafa maida hankali a cikin ginin, sannan an dakatar da allura kuma an yi rikodin maida hankali ga maida hankali da wani matsayi, kuma an yi amfani da Tracer Gas Step-Up na biyu, inda aka yi amfani leken gas a cikin daidaitattun lokaci kuma an yi rajista kuma an yi lissafin amsawar maida hankali.

## Rashin iska a cikin gini
Hanyar da aka fi sani da ita don auna iska ita ce hanyar matsin lamba, wanda aka fi sani le gwajin ƙofar mai hurawa. Ana auna shi ta yawan canje-canjen iska a kowace awa (ACH) wanda ke faruwa lokacin da akwai matsin lamba na 50 pascals tsakanin waje da ciki na ginin. Idan ƙarar iska daidai da ƙarar ciki na ginin yana gudana a fadin ambulaf a cikin awa ɗaya, to ACH = 1. Airtightness yana inganta aikin makamashi na gine-gine tun lokacin da ƙananan matakan iska ke nuna ƙimar shiga, zane, haɗarin kwantar da hankali, da tarawar danshi, da sauran sakamako. Saboda wannan dalili, ma'auni na Passive House ya kafa bukatun aiki don iska wanda ke buƙatar zama ƙasa da 0.6 ACH tare da bambancin matsin lamba tsakanin ciki da waje na 50 Pa.&nbsp;&nbsp;&nbsp;

Ya kamata a lura cewa ACH da aka auna tare da gwajin ƙofar mai hurawa, a matsin lamba na 50 pascals, yana kwaikwayon halin da ake ciki na iska mai ɗorewa 20 mph (32 km / h) a waje. Rashin iska na halitta, a ƙarƙashin yanayin kwanciyar hankali, mai yiwuwa ya zama ƙasa da haka. A sakamakon haka, abin da ake kira ACH na halitta na iya zama ƙarami sau 10-25. Wannan yana da mahimmanci tunda hanyoyin gine-gine masu inganci suna ƙoƙari su kiyaye ACH a ƙarƙashin daidaitaccen yanayi, yayin da la'akari da ingancin iska na iya buƙatar isasshen ACH na halitta.

## Manazarta