Professionel Och DIY Installation

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Detta dokument assisterar dig i generel installation av värmeåtervinningsfläktar
INTRODUKTION. NORRA EUROPA..............................................................................................................................2
VAD GÖR EN FAHRENERGY FTX FÖR MIG? ............................................................................................................2
SPARAD ENERGI ...............................................................................................................................................................2
VILKEN FTX ÄR BÄST? ...................................................................................................................................................3
HÅLL LUFTFLÖDESMOTSTÅNDET LÅGT ..............................................................................................................................3
Allmänna Filter Överväganden.....................................................................................................................................4
PROFESSIONAL OCH DIY (GÖR DET SJÄLV) INSTALLATION ............................................................................4
VAR SKA JAG HÄMTA DEN FRISKA LUFTEN?........................................................................................................................5
Direkt utifrån ................................................................................................................................................................5
Förvärmd Fresh Air ......................................................................................................................................................5
Samla Fri energi ...........................................................................................................................................................6
Energi från källaren (FTXen fungerar ochså som en avfuktare) ..................................................................................7
From The Crawlspace .................................................................................................................................................................8
No Loft And / Or Cellar ..............................................................................................................................................................8
FIND THE BEST PLACE .......................................................................................................................................................9
Short Ducts = Higher Energy Efficiency And Lower Price ..........................................................................................9
Energy Reduction And Efficiency..................................................................................................................................9
SPECIAL INSTALLATION CONSIDERATIONS .........................................................................................................................9
Make It Look Pleasant ................................................................................................................................................10
TWO STOREY HOUSE HRV INSTALLATION ......................................................................................................................11
ONE STOREY HOUSE HRV INSTALLATION .......................................................................................................................11
AIR VOLUME NEEDED ......................................................................................................................................................12
Buildings Regulations Part F: Ventilation..................................................................................................................12
Radon ..........................................................................................................................................................................12
Smoking And Fireplaces .............................................................................................................................................13
MOISTURE AND CONDENSATION AT 80% HRV SYSTEM EFFICIENCY .............................................................................13
High Temperature Efficiency Gives Low Energy Efficiency. ......................................................................................14
Correct Installation Prevents Condensation...............................................................................................................14
COMBINE HRV AND HP ..................................................................................................................................................15
WALL FAN DISPLACES DUCTS..........................................................................................................................................15
HOLES FOR DUCTS ...........................................................................................................................................................15
INSULATING DUCTS ..........................................................................................................................................................16
How much insulation is needed?.................................................................................................................................16
Duct Insulation............................................................................................................................................................18
INSULATION / INSTALLATION EXAMPLES: ........................................................................................................................18
ATTACHING FAHRENERGY POWER HRV ........................................................................................................................19
ADJUSTING THE AIRFLOW ................................................................................................................................................20
MEASURING THE EFFICIENCY...........................................................................................................................................21
APPENDIX .........................................................................................................................................................................21
TOOLS ..............................................................................................................................................................................21
PARTS ...............................................................................................................................................................................22
INSTRUMENTS ...................................................................................................................................................................23
Efficiency measurements of a system. .........................................................................................................................23
STANDARDS ......................................................................................................................................................................24
MOULD .............................................................................................................................................................................24
LOFT ENERGY MEASUREMENTS .......................................................................................................................................24
AUTOMATIC CONTROL ERROR .........................................................................................................................................25
DISCLAIMER ....................................................................................................................................................................26
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Introduktion. Norra Europa.
Detta installationsdokument gäller för norra Europa.
Norra Europa har en kall vinter och en mild sommer. Längre varmare perioder är sällsynta. Vanligen
är det kallare utomhus än inomhus.
Vad gör en FAHRenergy FTX för mig?
1: Den utväxlar gammal unken luft mot frisk luft uppvärmd av den gamla luften.
Det betyder att den friska luften blir uppvärmd av värmen (energien) från den gamla luften.
Detta kallas frisk luft värmeåtervinning (FTX).
2: Den hämtar gratis solenergi från vinden / loftet utan extra utstyr eller installation.
3: Den hämtar gratis energi från källaren / krypgrunden.
4: Den avfuktar ditt hus utom extra energi, helt gratis.
Du sparar avfuktaren och energi.
5: Den tar bort radon utom extra kostnad:
Vanlig radonsanering och energi sparad.
6: Den sparar energi och därmed pengar. Härvid minskas föroreningen.
7: Då den friska luften kontinuerligt utbyter den gamla luften är där ingen trykkändring.
Varvid förhindras att gammal luft passerar genom huset.
8: FAHRenergy användar kortrörs konceptet:
Korta rör är billigare och lättare att installera
Short ducts lose little energy
Short ducts need little or no insulation
Short ducts give higher financial return
Short ducts are easy to hide
Short ducts creates less noise
FAHRenergy Power HRV is designed for short ducts
Sparad Energi
En FTX återvinner energien från den gamla luften för denna utblåsas ur huset.
Energien som kan sparas huvudsaklig avhänglig av luftvolumen och temperaturskellnaden mellan
gammalluften och friskluften som passerar igenom FTXen.
Djuptgående undersökning av energibesparningen som kan fås från ett vanligt hus finns på websidan:
http://www.fahrenergy.org.uk/install/
Klicka på: Energy Reduction For Existing Homes
Se ochså: http://www.flobymetallprodukter.se/Energireduktion2.html
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Vilken FTX är bäst?
Vad är bäst: En stor eller två mindra?
FAHRenergy Konceptet: Flera små är bättra än en stor
• Allmänna installationskostnader halveras genom att använda två eller flera mindre FTXer jämfört
med en stor FTX.
• Detta koncept reducerar också längden på rör, antal böjar osv. Mindre energi går förlorad och
därmed mer energi sparas.
• Flera mindre FTXer förhindrar bakterier, virus, jäst och svamp från att flytta från ett område till
ett annat.
• Buller är lättare att reducera.
FAHRenergy’s
Power, Ultra, HRV-Solar och Berserk FTXer
har utformats för att utnyttja detta koncept
Undvik en stort FTX:
Standard konceptet använder en stor FTX. Det är dyrt att installera, använder onödigt mycket energi
och överför sjukdomar från ett område till ett annat.
Buller är svårt att reducera.
Håll luftflödesmotståndet Lågt
Rör som behövs för att suga ut den gamla luften och utväxla den mot frisk luft bör vara korta och
aldrig sträcka sig mellan våningsplan.
Korta rör
Korta rör är billigare att installera, lättare att rengöra och förlorar mindre energi.
Varje meter rör skapar ett motstånd mot flödet av luften.
Genom att använda så många FTX enheter som förnuftigt, reduceras rörlängden till ett minimum.
Korta rör är lätta att rengöra.
Med tiden lägger dammet sig i ventilationssystemet och det måste rengöras.
Korta rör kan rengöras med en rör borste, liknande eller identisk med en skorsten sopborste.
Långa kanaler med böjar är dyra att rengöra. En kraftfull fläkt behövs för att bistå rengöringen.
Inga rör mellan våningsplanen.
Varm luft stiger.
Om du flyttar varmare luft 2 meter ner behövs åtskilligt mer energi.
Då en FTX alltid har en kall och en varm luftström ska du aldrig använda bara en FAHRenergy utan
minnst två Power för två våningar.
Genom att använda minst en FTX per våning, blir det inga rör mellan våningarna och energi vinsten
stiger.
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Undvik Böjar
Böjar ökar luftmotståndet.
Förnuftig utformning av anläggningen minskar antalet böjar till ett minimum.
Genom att använda mer än en FTX kan ytterligare böjar reduceras.
Allmänna Filter Överväganden
Använd endast filter när det är nödvändigt.
Varje filter kräver energi för att trycka luften genom filtret. Använd rätt filter.
Ju större filterytan är dess mindre kommer luftmotståndet att bli. Under tiden kompenserar detta den
extra kostnaden.
Det finns ingen anledning att filtrera OAI (gamla luft in i enheten) om du använder FAHRenergy’s
FTX.
FAHRenergy’s design har ökat det interna luftflödet, vilket förhindrar dammet att fästna i enheten.
(De flesta FTX typer behöver ett filter i OAI. Detta minskar den energi som återvinns genom ett sådant FTX-system)
Det finns ingen anledning att filtrera OAO (gammal luft ut ur enheten).
På landet och nära havet är luften frisk och sund. FAI (frisk luft in i enheten) behöver inte filtreras.
Större städer kan ha stora mängdar kolpartiklar från bilavgaser i luften.
Ett FAI (friskluft in i enheten) filter kan behövs. Använd en filtertyp som är in-line med röret.
Du kommer att behöva lägga en kanalfläkt i röret för att kompensera för luftförlusten.
Pollenfilter i FAI (friskluft in i enheten) är nödvändigt om innehavaren är allergisk mot pollen.
Använd en filtertyp som är i linje med röret. Du kommer att behöva lägga en kanalfläkt i röret för att
kompensera för luftförlusten filtret skapar.
Mer om filter:
www.fahrenergy.org.uk/install
Clicka på: Filters For Ventilation
Resultatet:
En stor enhet kräver rör som går igenom hela huset. Det är dyrt att installera, ineffektivt och bullrigt.
En liten enhet som levererar till ett par rum är lätt att installera. Korta rör räker. För att lämna friskluft
till ytterligare rum eller våningar måsta fler enheter används.
Detta är effektivare, billigare att installera, har liten inverkan på insidan av huset och buller är lättare
att reducerar.
Professional Och DIY (gör det själv) Installation
En professionell installerar vanligen ett FAHRenergy FTX på 8 timmar.
En DIY (gör det själv) person behöver mer tid än en professional.
Gör det till en lycklig tid. Ta det lugnt. Stressa inte.
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Du kommer förmodligen behöva ett par resor till olika lokala butiker eller köpcentrum för delar och
verktyg.
Om du använder tre gånger längre än de professionella, kommer din faktiska timlön (efter skatt osv)
vara samma som för den professionella!
Var ska jag hämta den friska luften?
Informationerna nedan är noggrant testade 2006-2013 på flera ställen i Skottland och Sverige.
För att uppnå bästa energiåtervinning har FAHRenergy kombinerat teoretiska kunskaper med
praktiska tester.
Utrustning som används är anemometrar, differens tryck mätare, olika termometrar, IR-termometrar,
dataloggrar med temperatur och relativ fuktighet sensorer.
Testerna har visat att allmän ventilations kunskap är baserad på felaktiga hörsägen och anekdoter.
Om friskluft: www.fahrenergy.org.uk/install/FreshAir.pdf
Direkt utifrån
Att hämta friskluften direkt utifrån bör undvikas. Energi kommer att förloras och fuktigheten i
friskluftsintaget stiger.
Läs om andra alternativ nedan och du kommer att förstå varför.
Förvärmd Fresh Air
Samla friskluften från loftet.
Hörsägen och anekdoter om fukt, kondens och mögel frodas.
Ett exempel:
I Wikipedia angavs att luft vid temperaturer under 0°C förvandlas till is i ventilationssystemet. Luft
vid temperaturer under 0°C förvandlas inte till is. Om så var fallet kunde man inte röra sig i 0°C luft!
Is är fruset vatten, inte frysta luft.
In this document we use years of practical and theoretical knowledge.
Genom att kyla luften ökar den relativa fuktigheten eftersom kallare luft "rymmer" mindre vatten.
Fukt uppstår när temperaturen har sänkts till eller under daggpunkten. Fukt kan aldrig uppstå när
lufttemperaturen ökar eftersom varmare luft "rymmer" mer vatten.
Vissa mögel kan torkas bort, men inte när det växer i mattan, väggar osv.
Var medveten om att alla mögel är en potentiell hälsokälla. Se appendix, mögel.
Ett typiskt hus behöver ca 150m3 luft per timme. När denna volym tas varje timme från loftet,
kommer luften på loftet vara så frisk som utomhusluften inom några timmar. Alla hus har rättvis
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rännil ventilation på vinden för att förhindra röta och mögel. Genom utsug av frisk luft från vinden
passerar en konstant större volym luft genom loft och således avsevärt förbättrar vindens ventilation.
Rot-och mögel har nu mycket mindre chans att bildas än tidigare.
Samla Fri energi
At ta den friske luften från vinden och använda den för ventilation är inte nytt. Den nya utvecklingen är att
använda en FTX (HRV).
FTXen återvinner båda värmen från loftet och den gamla unkna luften från huset. Mer energi är sålunda
tillgänglig.
Under vintern (norra EU) tränger en del energi (värme) igenom isoleringen mellan taket och vinden.
Detta höjer loft temperatur lite och minskar fuktigheten. Genom att utvinna den friska luften från
loftet och mata den till FTXen, återvinns en del av denna energi av FTXen.
Detta har en liknande effekt som en fördubbling av nuvarande isoleringen skulle ha. Mer om detta
här: http://www.fahrenergy.co.uk/FAHRenergyAndHeatPump.html
Under våren och hösten ganska fri solenergi matas till loftet. Det är vår erfarenhet att
uppvärmningstiden minskas med två månader genom att återvinna denna energi med FTXen.
Du hittar också att den bättre ventilation minskar den höga loft sommartemperatur och därmed
minskar den energi som nu tränger från loftet till rummen genom isoleringen (motsatsen till vintern).
Ditt hus hålls svalare utan extra kostnad.
En extra bonus: FAHRenergy FTX växlar automatiskt till kyla när utomhustemperaturen är större än
innetemperaturen.
En FTX sparar också energi under varma perioder förutsatt sitt CoP (Coefficient of Power) är hög.
FAHRenergy Power har en mycket hög CoP på över 20.
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Friskluftsinsektsfilter. Flexibel aluminiumrör . Buller dämpare (rörljuddämpare).
HRV Power on the loft
Insulated
cardboard box
Fresh air in from the loft
(adjustable)
Notera friskluftsintaget från loftet. Denna typ sprider den kylaren friske luften över en del av taket.
Det hjälper till att utjämna temperaturen i rummet och ger en fin fräsch känsla.
Set från ovan är FAHRenergy Power med 100mm anslutningar och ingen skyddande hölje. Det är
den billigaste versionen. Hemgjord isolerade pappskydd som visas ovan minskar
installationskostnaden till ett minimum. Isoleringen minskar ytterligare värmeförlust hos FTXen när
temperaturen faller.
FAHRenergy Power+ och FAHRenergy Ultra+
skyddas av ett aluminiumhölje och är utrustad med
125mm röranslutningar (aborter). Denna version är
dyrare och är avsedda för mindre avskilda
utrymmen än ett loft.
FAHRenergy HRV i en aluminium hölje
Energi från källaren (FTXen fungerar ochså som en avfuktare)
En källare, i diskussionen nedan, kan vara en icke-ockuperade utrymmet nedanför huset utan någon
uppvärmning kanske bortsett från en panna. Vilken särskild källarutrymme bör användas beror på
lokala förhållanden.
Pannrummet eller grovkök skulle vara det första valet. I ett tvåvåningshus är det klokt att ta den friska
luften för övervåningen från loftet. För bottenvåningen bör den tas ur källaren, om sådan finns. Detta
koncept reducerar installationskostnaden då installationstid och material reduceras till ett minimum.
Det är också en mindre påträngande installation med en högre effektivitet.
Rörena bör göras så korta och raka som möjligt av ovanstående skäl.
Hörsägen, anekdoter och ogrundade antaganden gör att många tror en källare är fuktig, unken och
ohälsosam. Utan tillräckligt med frisk luft är den det.
Inte så när en kontinuerlig tillräcklig friskluftsvolymen passerar genom källaren.
Även en normalt mycket fuktig källare blir acceptabelt torrt i några få dagar. Luften kommer att bli
frisk.
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Genom en FTX samlas ganska myket energi från källaren på vintern.
Att ta energi från källaren under vintern kyler källaren men inte mycket. När källartemperatur sjunker
under jämviktstemperaturen, kommer energi strömma in från omgivningen.
Om en källare förlora för mycket energi på grund av dåliga fönster och brist på isolering då förbättra
fönstren och isolera väggarna med 7cm polyuretan (eller liknande) till 0,6 meter under marknivån.
Detta är tillräckligt för att förhindra frysning av vattenledningar i de flesta områden.
Under sommaren kommer källaren att ha en något högre temperatur än tidigare på grund av den
förbättrade inflödet av frisk luft. Detta hjälper till att minska fukt i källaren. Den konstant friske
luften som passerar genom källaren gör at den motsvarar den relativa fuktigheten på utsidan. Detta
minskar ytterligare fukt och därmed kondensation.
Endast mycket varma, fuktiga dagar kan leda till kondens. Sådana dagar är sällsynta i norra Europa.
Vår mångåriga erfarenhet har visat att det inte behövs avfuktare förutsatt att FTXen är aktiv 24
timmar om dygnet och korrekt installerad.
HRV installed at this time
Note the drop in moisture
(RH%) from 100% to 90%
in a couple of days after
the HRV installation.
The next four years RH%
stayed below 90%:
No cellar moisture since
the HRV installation
The yearly cellar
temperature with
no heating in the
cellar and an active
HRV in Sweden.
Winter 2010
dropped to –24°C
yet no frost in the
cellar.
From The Crawlspace
When a two-storey house has no cellar but a crawl space, the fresh air for the ground level should be
excavated from the crawl space.
The function on energy collection and dehumidifying action is as for the cellar.
It is important that foundation vents are open and free for the air to pass.
The volume of the crawl space should be smaller than the hourly air volume exchanged by the HRV.
Spider web and dust in the vents reduce the flow of air! Keep the vents clean.
No Loft And / Or Cellar
FAHRenergy
Power HRV
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Where there is will there
is way.
FAHRenergy Power HRV needs little space. A kitchen cupboard will do.
You may even hide it behind a curtain and add a Smokers Corner.
The OAI intake holds an ashtray.
Find The Best Place
First we have to understand the basics:
Old Air Out (OAO) and Fresh Air In
(FAI) resides on the COLD side.
Fresh Air Out (FAO) and Old Air In
(OAI) resides on the WARM side.
In this document OUT is out of the unit and IN is into the unit.
Short Ducts = Higher Energy Efficiency And Lower Price
The energy supplied to the fans forces the air through the ducts. As the air passes through the ducts,
energy is lost.
The less energy we lose the higher our return will be.
Keep the ducts as short and straight as possible.
Preferably less than 2 meters of ducting for each of the 4 terminations (duct connections) of the
FAHRenergy Power HRV for 100mm ducts and 3.2 meters for 125mm ducts.
As the duct length increases the air volume decreases. Less air volume carries less energy. Of course
fan energy could be increased but this increases the loss and reduces the system CoP.
Energy Reduction And Efficiency
See http://www.fahrenergy.org.uk/install/Energy_Reduction_For_Existing_Homes.pdf
Special Installation Considerations
FAHRenergy Power HRV’s are designed to achieve highest efficiency at the lowest installation and
energy cost.
To reduce the energy consumption the fans are of low pressure type. Sufficient to deliver to 90m3 of
fresh air while extracting 90m3 of old air (i.e. it moves 180m3 of air) per hour.
FAHRenergy Power is not designed to press fresh warm air down to a colder, lower level. Should you
need this you will need to add an assisting fan.
The reason: Warm air rises. To force it down extra energy is needed.
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Distributing warm air (max 45°C) from a heater of any kind down to a lower level demands energy
determined by the temperature difference between the two levels as well as the air volume needed.
Avoid the above situation. Place the HRV at the level it shall serve.
Make It Look Pleasant
Although inlet and outlet vents may be bought for small
not all fit into the style of the room.
money,
The inlet vent on the picture distributes the fresh air across
ceiling.
Being a part of the lamp makes it fit right in.
the
Click the link for a large picture
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Two Storey House HRV Installation
Extract old air from moist and smelly rooms.
Place the FAHRenergy Power HRV in the loft, attic, cellar and/or crawlspace.
Supply fresh air to lounges and rooms.
One Storey House HRV Installation
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Extract old air from moist and smelly rooms.
Ridge vent
Place the FAHRenergy Power HRV in the loft, attic, cellar and/or crawlspace.
Supply fresh air to lounges and rooms.
Air Volume Needed
As a good rule of thumb an air volume of 1.25m3 per m2 dwelling per hour is adequate air exchange
for a private home.
This covers a fair number of persons occupying the dwelling.
Buildings Regulations Part F: Ventilation
The government ventilation examples obtained from the link below are obviously made by
bureaucrats. By shifting through it you will find that 25l/sec for a 84m2 heated area (dwelling area) is
needed. This corresponds to 1.1m3 of fresh air per hour per m2 of dwelling area (2 persons occupying
the house).
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADF_2010.pdf
Assure Loft, Cellar And Crawl-space Are Adequitely Ventilated
It is our experience that loft and cellar are sufficiently ventilated if the air is exchanged at least once
every hour. At this rate mouldy and moist air is quickly removed and will be as fresh as the outside
air within hours.
The crawl space may need more air if the ground is excessively moist.
Radon
Possibly the best way to keep a house below the radon limit of 200beq/m3 is by sufficient ventilation.
As the volume of fresh air will be larger than demanded by the building regulation, you will need a
HRV to recover the heat from the old air. In many cases you will need twice the normal air volume to
stay below the radon limit. Without a HRV too much energy is lost.
More here: http://www.fahrenergy.co.uk/Radon.html
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Dust In The Rooms
Radon mitigation, through HRV ventilation, also removes the dust suspended in the air. This is
valuable as the radon daughters that are created through the radioactive decay of radon gases, become
attached to dust particles which then enters the lungs through breathing. One dust particle may have
several radon daughters attached and thus the danger is similarly increased.
As it is the radon daughters that are dangerous through alpha ray emissions less dust particles means
less radon daughters in the lungs. The danger is mitigated.
Smoking And Fireplaces
Smoking and burning fireplaces creates small carbon particles that especially attract radon daughters.
Due to this both smoking and fireplaces should be omitted when radon is present.
The danger from carbon particles is also reduced as the HRV ventilation system removes these
particles.
See: http://www.msha.gov/illness_prevention/healthtopics/hhicm09.htm
In some homes the radon influx from cracks, pipes, electrical wires and other installations that enters
the building is too high. By finding and closing these places it is possible to reduce the radon level
below the current limit.
Moisture And Condensation At 80% HRV System Efficiency
Moisture is water molecules suspended in the air. A conglomeration of these molecules become
droplets.
The relative volume of water the air holds depends on the air temperature. This we call Relative
Humidity (RH). At 100% RH the humidity condenses to water.
As such water condensates build up moisture, mildew, mould and rot may appear. This we have to
prevent.
Some simple methods make it quite easy to prevent condensation in our ventilation system.
First we must know a bit about relative humidity. A rule of thumb helps:
For every degree Celsius the RH changes 3%
When temperature increase the RH is reduced
When temperature decrease the RH is increased
Example-1: Outside temperature is 5°C. Outside humidity is 99%. As this air is heated (increased) to
the inside house temperature of 20°C, the relative humidity (RH) of this air will be reduced.
The temperature increase is 20-5 = 15°C. The new RH will be reduced by 15*3= 45 RH%.
Thus the new RH will be the old RH – the RH reduction = 99-45 = 54%.
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As the HRV constantly exchanges the inside old air with fresh, preheated air, any humidity added by
the occupier is small.
At 80% temperature recovery the inside 20°C is reduced by 20-5 = 15°C multiplied by the efficiency
(80% means 80/100). This is 15*0.8= 12°C. The OAO humidity is thus increased by 12*3 = 36%.
This makes the OAO humidity 54+36 = 90%.
There are still 10% to go minus the humidity added by the occupier before condensation in the OAO
(Old Air Out of the HRV) may occur. This is an acceptable margin.
At 80% HRV system efficiency the overall energy efficiency is high!
High Temperature Efficiency Gives Low Energy Efficiency.
Had the system efficiency been higher than 80%, the humidity margin would be smaller and
excessive condensation could occur.
To obtain a higher HRV efficiency many manufacturers mitigate the condensation problem by adding
electric heaters. As such heaters are of much less efficiency than most other heating systems, the
added HRV efficiency is wasted and the control of the heating system of the house is lost.
Of course many HRV manufacturers add electronic control systems to reduce the use of the heaters
and thus compensate the heating consumption. The effect is poor and added electronics make these
devices more vulnerable to failure and fire. The CoP is very low.
High HRV system efficiency reduces the overall energy efficiency!
One may wonder why such designs are made.
The reason is more understandable when one considers the past low energy prices.
The customer would say that the incoming fresh air is cold as it is colder than the inside air and
moving.
By adding a heater the customer is made to believe the apparatus is improved. It is much more
difficult to perceive that the recovered energy is used for condensation mitigation.
At todays energy prices and demand for energy reduction this technique is questionable.
Such a design carries a considerable price increase. Due to this it must ventilate the entire house. It
becomes larger and more expensive to install.
Correct Installation Prevents Condensation
Obtain the old air (OAI) (Old Air Into the HRV) from a heated room and the fresh air (FAI) (Fresh Air Into
the HRV) from a non heated space such as the loft, attic, crawl space or a cool cellar.
This ensures that OAO (Old Air Out of the HRV) will be warmer than FAI.
OAO temperature must be higher than the FAI temperature
This will prevent condensation in the HRV as the air is not cooled below the dew point..
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The above is correct for north Europe. On some rare days in north Europe the outside temperature
might be warmer than the inside temperature for a couple of hours a day.
If this is associated with very moist outside air, condensation in the HRV could occur as the FAI is
cooled by the lower temperature of the OAI.
Should it happen you may switch off the HRV during such a period.
During 5 years and hundreds of installations in Scotland an Sweden no condensation have been
observed in a HRV installed as stated above.
The outside temperature ranged from -25°C to +32°C.
Condensation Tray
In areas where condensation is observed or expected one should place
condensation tray under the HRV. Attach a hose that leads from the
the outside.
The FAHRenergy HRV’s should be place such that the fans are up
Combine HRV And HP
A Heat Pump (HP) is an air conditioning unit in
mode: It heats inside and cools outside. This is
achieved by an inside and outside unit.
This heat pump mode has value during cold
a
tray to
high.
The picture shows the
fresh air duct from the
FAHRenergy unit
supplying the heat
pump.
reverse
periods.
The inside unit passes the inside air through its heated radiator and thus heats up the inside air. As the
inside air normally becomes filled with dust, the inside unit is provided with a coarse dust filter. A
couple of weeks suffice to cover the radiator with dust. The efficiency is drastically reduced.
By providing the heat pump with fresh air from the FAHRenergy heat recovery unit the dust problem
is virtually eliminated. Maintenance has been reduced from weeks to month.
A bit more about this is found here:
http://www.fahrenergy.co.uk/FAHRenergyAndHeatPump.html
Wall Fan Displaces Ducts
In some cases less energy is used by blowing fresh air from one room to another by means of a fan
rather than by ducting.
More here: http://www.fahrenergy.co.uk/WallFixtureGrid.jpg
Holes For Ducts
Before you make any hole in any wall check for wires, pipes and beams in the
Instruments for sensing wires, metal and wooden beams are available in most
building and DIY stores. The picture shows such a device
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You will have to get used to such an instrument. Try it out on a wall you know.
Observe that some wall claddings change the sensitivity. Use common sense.
Check for wires, metal and beams. Avoid making holes in beams. It may become a large task to make
a hole in a 12cm beam.
Solid wooden walls are common in Scandinavia. On such a wall you will have to work.
Masonry
Use a 102mm or 105mm hole saw for 100mm ducts.
Common holes saws are for wood, gypsum board and similar.
If you need a hole through a thick wooden wall you will need to assist the saw with a chisel.
Concrete
To make a hole in concrete use a Concrete Core drilling machine. The picture show
one having an attachment which makes holes in floors easier.
such
Hire the machine. Many building stores hire such tools.
Fix The Duct
Every so often you will have to fix the duct. It is easy and often possible to do this by means of metal
bands with holes.
Insulating Ducts
Some ducts needs to be insulated to prevent loss of energy and building of condensation.
Use always a mouth filter when you work with insulation and in dusty conditions.
1: A duct surface that are colder than the space it passes through may create condensation on its
external surface (cold duct that passes through a warmer space). It will need insulation to prevent
condensation.
2: A warm duct which passes through a cold space will need insulation to preserve the heat and
prevent internal condensation.
How much insulation is needed?
The insulation quality depends on the type of insulation material and thickness.
Below is a general table of heat loss in watt per m2 per degree Celsius, as a function of the insulation
thickness.
Mineral wool
5cm loses 0.8[w/m2C]
10cm loses 0.4[w/m2C]
20cm loses 0.2[w/m2C]
30cm loses 0.13[w/m2C]
40cm loses 0.1[w/m2C]
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Insulation Of A Standard HRV Installation
In reference to the picture to the right:
The OAI and FAO are carrying warm air. They are
a yellowish colour.
The part of the warm ducts that are on the cold loft
insulated.
shown in
must be
If the lowest loft temperature is -9°C and the internal duct temperature is 14°C. then we have a
temperature difference of 23°C.
The duct is 1m long and has a diameter of 100mm. This gives a duct surface of 0.31m2.
By using a 5cm thick mineral wool we lose 0.8*0.31 = 0.25W per °C. The loss would be 0.25*23 =
5.8W.
During an average 100 days winter at a temperature of 2°C outside and 20°C in the house the duct
would lose 100*18*0.25*24 = 10.8kWh per duct meter.
As a common FAHRenergy installation uses a total of 3m ducting on the warm side (OAI, FAO) the
loss would be 3*10.8 = 32.4kWh. This becomes twice as much during a whole year = 64.8kWh,
which is acceptable.
Without the duct insulation the installation would be near worthless and create condensation.
In reference to the picture:
FAI (shown blue) excavates the fresh air from the loft. If the duct is short no insulation is needed.
OAO (shown blue) expels the old heat exchanged air. As this still has some energy left it may be
warmer than the loft air. The OAO may be cooled by the colder loft air. Condensation could occur
inside the duct unless it is short.
If it is longer than 1m, insulation or a fair gradient which lets the condensate run out, is needed.
During northern summers the temperature difference is relatively small and thus the RH change.
Condensation is unlikely on short ducts.
A HRV that is placed in a cold room needs some insulation or condensation may occur.
Short ducts are cheap and easily installed
Short ducts lose little energy
Short ducts need little or no insulation
Short ducts give higher financial return
Short ducts are easy to hide
Short ducts creates less noise
FAHRenergy Power HRV is designed for short ducts
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Duct Insulation
In loft spaces existing insulation may be used. Simply place the ducts that need to be insulated under
the existing insulation. This is a quick, cheap and very effective method.
Mark the position of the ducts that are hidden under the insulation to prevent unexpected visitors
from walking on the ducts.
In reference to the picture to the right:
Under the floorboards the HRV has been positioned
a box for easier access.
FAI insect hood will be
attached here (cold side)
in
The two warm side ducts are placed in the existing
insulation between the ceiling of the room underneath
and the floorboards.
The entire installation creates very little obstructions
and is insulated at no extra cost. The floorboards
above the HRV are modified to allow for easy access.
The OAI (Old Air Into the HRV) and the OAO (Old Air Out of the HRV) use the existing toilet extraction
duct. The duct was simply cut such that the one side would be OAI and the other OAO.
FAI (Fresh Air In) was extracted from the loft. An insect hood was placed on the intake.
FAO (Fresh Air Out) was led to two room through holes cut in the ceiling.
The power supply was placed on the loft, out of the way of kids and pets.
Insulation / Installation Examples:
http://www.fahrenergy.co.uk/Examples.html
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Attaching FAHRenergy Power HRV
The transport / installation brackets may be directly attached to the floor, wall or ceiling.
I suggest that the installation brackets are attached to a board having a minimum size of
590mm*285mm. The board may be of MDF chip-wood or plywood.
Place the HRV with the installation brackets
attached to it on the board.
Mark the 8 holes for the installation brackets.
Remove the brackets from the HRV and
screw them onto the
board using very
short and small
screws.
Do NOT tighten the
screws. Ensure that
the bracket can
wobble.
The HRV weighs less than 4kg. A 6mm thick board and similarly small screws are strong enough to
hold it.
To fix the board on a wall you need one hole at each end
of the board.
Attach the HRV to the board by gently pushing the
installation brackets ‘over’ the HRV terminations.
A
If the HRV shall sit on a wall or a ceiling you will need
to fix the brackets to the terminations of the HRV. Do
this by drilling a 3mm hole through the bracket where it
attaches to the termination and screw in a 3.5mm to
4mm thick small screw. See point ‘A’ on the picture.
The bracket is now prevented from losing its grip on the HRV
To be able to remove the HRV from the brackets the first 30cm of ducting which connects to the
brackets must be flexible.
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Deciding FAI, FAO, OAI And OAO
The 2 fans blow into the HRV.
Either of these terminations may be only appointed as FAI or OAI.
The 2 remaining terminations may only be appointed as FAO or OAO
The delivered FAI, FAO, OAI, OAO adhesive labels are to be attached to the corresponding selected
termination. There are only 2 options:
Warm to the right
Warm to the left
Adjusting The Airflow
The best energy recovery is obtained at maximum airflow of the FAHRenergy Power HRV.
FAHRenergy Power HRV allows for selecting the airflow of balanced old / fresh air:
At 13.5V around 90m3 of old and fresh air is moved (a total of 180 m3). Noise < 54dBA
Noise < 47dBA
At 9V around 65m3 of old and fresh air is moved (a total of 130 m3).
3
3
Noise < 45dBA
At 6V around 50m of old and fresh air is moved (a total of 100 m ).
Adjust the airflow in the installed system by adjusting the FAI and AOI. Adjustable air disc valves
and diffusers both round and square are available from your ventilation store.
Attempt to obtain the same FAO and OAO airflow. The best result is obtained by the installation
design.
If the duct length of fresh air and old air are the same and the bends are minimised you probably have
a good balance by design.
Measuring The Airflow
Important: All electronic instruments are sensitive to magnetic pulses. Due to this you will find that
you cannot measure with the instrument close to the ECM (Electronically Commutated Motors)
which are used in FAHRenergy’s HRV’s.
Measuring the airflow is not easy at low airspeeds. Low airspeeds are used in FAHRenergy’s HRV’s
to obtain maximum energy recovery (minimum loss) and low ventilation noise.
The simplest and cheapest method to evaluate the balance of the ventilation system is by using a
large, soft plastic bag. Measure the time it takes to fill it to around 50%. Measure the volume of air
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you have filled into the bag. Divide the volume with time and you have the ‘airflow’. As it is the
same bag, the airflow restrictions the bag creates, are the same for both measurements.
This method also gives an idea of the airflow provided you have some knowledge of the restrictions
to the airflow the bag created.
Vane anemometers are relative cheap with prices from £70. Most vane anemometers are inferior at
low airspeeds. You will get a reading but the precision is insufficient.
Measuring The Efficiency
See Measuring Ventilation Energy Efficiency
http://www.fahrenergy.org.uk/install/MeasuringEfficiency.pdf
Appendix
Tools
Avoid anything with cables when you work in tight spaces.
Drill bits
As you will need several drill bit sizes a cheap drill bit container may be bought in most DIY stores.
Use such a container for future drill bit storing.
Battery powered drill
Keep the costs down.
Use as cheap a drill as possible. Many low cost types suffices.
Buy at least two or even three. Should you forget one somewhere
the loss is affordable.
Hole Saws
44mm, 50mm, 102mm, 105mm and 127mm will make most of the necessary holes in a standard
installation.
Screw driver and nut driver bits.
You should use the battery powered drill as a screwdriver.
A couple of hand screwdrivers could be handy
Head lamp for dark spaces
Use a LED headlamp for dark spaces. At least a 1W LED is needed.
As you will have to move around a common work lamp is mainly in
the way.
Portable work bench
Battery powered tiger saw
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Parts
Wood and gypsum screw assortiment
Self drilling and tapping screw for nut driver bit for duct
assembly
Round metal ducts
Flexible aluminium ducts
Chimney ventilation ducts are commonly flexible aluminium ducts of a good quallity. A bit more
expensive but not as flimsy as the types commonly available.
Flexible plastic ducts
Round PVC ducts
Square PVC ducts
Noise reducing ducts (duct muffler, silencer)
Holed metal band
90° bend
Duct connector
Drill bits
Holed metal band. Grills, Flanges
90° and 45° bend. Duct connections
Parts shown to the right
are found in common DIY
stores.
Note that square ducts
often have a smaller area
than a 100mm round duct.
Due to this maximum
usable length is reduced to
1m.
Duct area should be 78cm2
or more.
100mm to 125mm adapter ducts (reducer)
T and Y joints
Where can I get ventilation parts?
At ventilation retailers, DIY stores and building retailers.
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Instruments
Efficiency measurements of a system.
See: www.fahrenergy.org.uk/install and click on Temperature And Energy Measurements
Anemometer http://uk.rsonline.com/web/search/searchBrowseAction.html?method=getProduct&R=5066033
The link is for a pocket vane anemometer. It is relatively cheap but acceptable.
Such an anemometer gives some idea of the airflow in an installed system.
Note that the air in a ventilation system often is not laminar. Exact airflow measurements are thus
quite difficult to obtain.
You will have to make several measurements using a vane anemometer at different angles of the duct
to get a feel for the airflow.
Another way to obtain the airflow (air volume per time unit) is placing a very soft, reasonable large
plastic bag around the duct (at least 50 litres). Just fill the bag to max 50%. Measure the time used
and measure the volume in the bag.
Divide the volume with the time and you have the airflow per time unit.
Of course this method restricts the airflow such that the actual result is somewhat larger than
measured using this method.
Wire, Metal And Beam Tester
Instruments for sensing wires, metal and wooden beams are available in most
DIY stores. The picture shows such a device.
The price ranges from £25 to £100.
Moisture meter Any DIY store
It is always a good idea to have some knowledge of the moisture in walls
beams before the ventilation is activated.
Measuring later one develops a good feel for the value of ventilation.
building and
and
A moisture meter using LED as indicator is cheap. It shos moisture present or not.
Infrared thermometer http://uk.rsonline.com/web/search/searchBrowseAction.html?method=getProduct&R=5168454
An infrared thermometer is not cheap.
It is a good immediate temperature indicator.
A standard thermometer cannot be used to obtain temperature
differences. To measure such you will need a datalogger.
USB thermal and humidity datalogger http://uk.rsonline.com/web/search/searchBrowseAction.html?method=getProduct&R=4901064&cm_vc=av_uk
A USB datalogger is the only one which may be left in a ventilation duct
and
elsewhere. It will collect data for up to one year.
A data curve is automatically written as the data are transferred to your
PC.
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Not everyone benefits from a datalogger.
Two or more dataloggers are needed to obtain temperature and humidity differences. These might
then be used to calculate energy movements and thus energy recovered.
You may also get instruments from:
Maplin http://www.maplin.co.uk/store-locator
Farnell http://uk.farnell.com/jsp/home/homepage.jsp?CMP=KNC-GUK-FUK-GENPFB&s_kwcid=TC|13123|farnell||S|e|7342426749
Standards
Recommended volume of fresh air per hour: 1.25m3 per square meter occupied space.
Filter standards. See www.fahrenergy.org.uk/install Click on Filters For Ventilation
Mould
Daily Mail July 2010: …the deaths of actress Brittany Murphy and her British screenwriter husband
Simon Monjack might have been caused by mould…
http://www.dailymail.co.uk/health/article-1297862/Brittany-Murphy-Mould-home-kill-actresssdeath-linked-fungus-LA-mansion.html
Extracts from the article:
…..Stachybotrys chartarum, which is also known as the toxic mould. This fungus may produce
spores which are poisonous by inhalation.
‘The common places for mould to grow in houses is wallpaper, flooring, behind wall tiles and on
window frames,’ explains Professor Richardson.
It may seem extraordinary, but in fact mould in the home is a common health problem, affecting tens
of thousands of people in the UK, explains Malcolm Richardson, Professor of medical mycology (the
study of mould) at the University of Manchester.
Professor Roy Watling, an authority on fungi and formerly head of mycology at the Royal Botanical
Garden, Edinburgh, says: 'When you walk around on the damp carpet, mould spores are released into
the atmosphere, which you can then inhale.
For Christine and John Frost, from Mansfield in Derbyshire, it comes as no surprise to learn that
mould can have a devastating effect on health.
Christine, 62, first noticed black mould on a wall in their living room three-and-a-half years ago…..
….The mould in our house totally destroyed us. It was just horrendous.’
Constant ventilation is necessary. Due to the high cost of heating, Heat Recovery Ventilation is
valuable. It is a very effective method to obtain fresh air at a very low running cost.
Loft Energy Measurements
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The above diagram shows the extra energy captured. The RH is safely above the dew point.
Automatic Control Error
Quite many ventilation and heat pump (air conditioning) devices are fitted with automatic controls
which are manipulated by the user via a remote control.
A ventilation system for a common home does not need such smart controls.
It should be set up once and then left to work.
Today’s heating systems are optimised by various automatic controls. As they are controlled by
temperature sensors they are easily ‘confused’.
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An example:
The occupier enjoys the fireplace. As the fireplace heated up the temperature in the room increased.
The inside unit of the heat pump was rather near the ceiling and the control (air-conditioning unit)
switched to cooling. The more the fireplace heated the more the HP cooled.
The occupier had not perceived this. He became very surprised when he found his electricity bill
increased after the HP installation.
The error was to have the HP (AC unit) set to ‘automatic’ by the manufacturer.
In fact, the use of the HP remote control was sufficiently complicated to prevent correct use by the
owner. This is not a special case. It is quite common.
Most HP (AC) may only be controlled through the remote controls. Often the LCD screen and the
writing on the buttons are too small. Quite many people cannot read such small letters.
Only Necessary Electronics In FAHRenergy HRV
FAHRenergy HRV’s are not fitted with compromising electronics. When FAHRenergy HRV’s are
installed correctly they function correctly and do not interfere with controlled heating systems.
Remote control is not necessary.
A yearly CoP of over 20, i.e. the recovered energy is 20 times larger than the energy consumed, is the
result.
No complex manual is necessary. No remote controls. Less potential errors.
Disclaimer
This manual is advisory.
It contains all information needed for the trained person.
Professional installation demands a FAHRenergy installation training.
All manuals prior to this edition are void and null.
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