Air source heat pumpsBy: Jasu Nousiainen

What is air source heat pump (ASHP)?

• According to Wikipedia, it is a heating and cooling system that uses outside air as its heat source

• More clearly said it is a machine that is used to cool or warm the air inside the house and which takes the heat from outside air

• ASHP has one or more inside compartments• It works using almost the same basic working

principle as a fridge• Using ASHP is more ecological and economical than

warming the air in another way

Indoor compartment of a floor model air source heat pump

Outdoor compartment of ASHP

Basic working principle of ASHP

• ASHP has refrigerant inside it• When the refrigerant turns from liquid into

steam in an evaporator in low pressure, it binds heat into it

• When the refrigerant is turned back from steam into liquid in a condenser using high pressure, the heat is released into the house’s air

A: The part of ASHP that is in the house (indoor compartment)

B: The part of ASHP that is not in the house (outdoor compartment)

I: Insulation

1: Condenser

2: Expansion valve

3: Evaporator

4: Compressor

ASHP’s most important parts

3. First the refrigerant that is warmed by air is turned into steam in low pressure

4. After that steam is turned into liquid using high pressure

1. Because of that, heat is released into the house’s airWhen the air is wanted to

cool, the ”steps” are made in the opposite direction The cycle continues

How does it work?

The usage of air source heat pumps

• Based on its definition, ASHP is used to warm or cool the air inside the house

• In Finland ASHPs are used to warm air more often than to cool it

• That is because Finland’s climate is cold

Popularity of air source heat pumps

• The amount of sold air source heat pumps in Finland in 2012 was about 45 000

• Totally there was about 440 000 air source heat pumps in Finland that year

• That amount is over 8% of Finland’s population

• ASHPs are becoming more popular, as can be seen from following graphic

20002001

20022003

20042005

20062007

20082009

20102011

20120

50000

100000

150000

200000

250000

300000

350000

400000

450000

500000

Total approximate amount of air source heat pumps in Finland

Advantages of air source heat pump• Though the machines are still quite expensive

(about 1000€), it is cheaper than many other ways of warming (oil, ground source heat pump, electricity)

• The costs of ASHP are usually paid back in 2-5 years by about 30% smaller electricity bills

• ASHP can be used to warm and also to cool the inside air

• It is ecologically sustainable as it saves energy

What is not good in ASHP?• It could be cheaper (cost about 1000€)• It is recommend to have another way of

warming because the machine doesn’t definitely work under -25 °C or it may break

• ASHPs freeze easily • They produce a lot of water that during a long

time damages the foundations of the house• Noise may be a problem, specially in wooden

houses because wood resonates sounds well

ASHPs produce lots of water that freezes in negative temperature. Outdoor compartment of an ASHP

Sources

• http://en.wikipedia.org/wiki/Air_source_heat_pumps

• http://commons.wikimedia.org/wiki/File:Outunit_of_heat_pump.jpg

• http://fi.wikipedia.org/wiki/Ilmal%C3%A4mp%C3%B6pumppu

• http://en.wikipedia.org/wiki/File:Refrigerator-cycle.svg

http://www.sulpu.fi/documents/184029/209175/Lehdist%C3%B6tiedote%2C%20SULPU%2C%201.2013.pdf

http://www.sulpu.fi/documents/184029/208772/L%C3%A4mp%C3%B6pumppujen%20kokonaism%C3%A4%C3%A4r%C3%A4n%20kehitys%201996-2012.pdf

http://www.stek.fi/sahko_ja_rakentaja/lampopumput/fi_FI/ilmalampopumppu/

http://i380.photobucket.com/albums/oo244/nuffinkuvia/pumppen.jpg

Thank you for your time and watching this presentation!

Jasu Nousiainen from Erkko-lukio, Finland