Air Heat Pumps? In Oulu?

Besides looking at purchasing provisions for your home in Oulu, I will be looking at systems for the home which may influence your cost of living. the first of these is the Air Heat Pump which is becoming popular in Finnish homes.

This is a product making much headway in Finland. It is known as the Air Heat Pump (In Finnish: Ilmalämpöpumppu).

Benefits of a Heat Pump System

• Because a heat pump does not burn fuel, it is safer and cleaner to run than a gas powered furnace.


• A heat pump provides a more uniform temperature throughout a building. It does not produce a sudden blast of hot air as traditional furnaces do each time they kick on.


• In the heat mode, heat pumps do not dry out the air the way traditional heaters do. The higher humidity maintained by heat pumps during cold weather provides healthier environment.


• Heat pumps are more efficient and cost less to run than electric furnaces.


• Because heat pumps are used year round (for cooling as well as heating needs), they cost less per hour of use (cost of purchase and installation divided by total number of hours used per year) than do individual heating and cooling systems, which each sit idle for a good part of the year.

Record sales are being reported in Sweden where the Government is helping to install these pumps so as to reduce the amount energy utilised for home heating in summer and air-conditioning in summer.

When I received a call a couple of days ago, I asked them to speak to Annikki, who set up for a representative to visit Kampitie to explain it to me.

A young sales representative, Sami Kiventerä, representing the company Pumppumestarit was on time. We spent about an hour going through the system.

Diagrammatic representations from HEAT PUMPS

Cooling Mode

• The compressor (1) pumps the refrigerant to the reversing valve (2).


• The reversing valve directs the flow to the outside coil (condenser) where the fan (3) cools and condenses the refrigerant to liquid.


• The air flowing across the coil removes heat (4) from the refrigerant


• The liquid refrigerant bypasses the first metering device and flows to the second metering device (6) at the inside coil (evaporator) where it is metered.


• Here it picks up heat energy from the air blowing (3) across the inside coil (evaporator) and the air comes out cooler (7). This is the air that blows into the home.


• The refrigerant vapor (8) then travels back to the reversing valve (9) to be directed to the compressor to start the cycle all over again (1).

Heating Mode

The difference in the two diagrams is the reversing valve (2) directs the compressed refrigerant to the inside coil first. This makes the inside coil the condenser and releases the heat energy (3-4). This heated air is ducted to the home. The outside coil is used to collect the heat energy (3-7). This now becomes the evaporator.

From what I know of heat pumps, it is generally efficient in countries which have average temperatures between -5 C and + 30 C. So the claim that it was useful in Oulu which has winter temperatures as low as -40 C and summer temperatures as high as +30 C, was of great interest to me.

The air heat pump works on the principle that it has a low temperature fluid which absorbs heat from the air and expands to be a gas, thereby cooling the air. In reverse it exchanges heat from the liquid to the air and can be liquefied again using a compressor.

The Finnish company is offering units from Sanyo and from Mitsubishi, both Japanese companies. Unlike most units, these work right down to -24 C and shut off at -25 C. At +7 C the efficiency is rated at 4.35 kw while at -24 C it is just 1.5 kw after which makes it no longer viable as a heat exchanger.

The main unit is located just outside the house and piping brings the liquid to the wall unit mounted inside the house. The unit inside the house has a fan which causes the air to be forced out at a rate of up to 5 cum / minute. It also has a thermostat unit which can be set to the temperature required.

By careful balancing of this along with the main home heating system, the company claims a reduction of 30 to 40 % in energy utilisation.

The sound generated by the fan is a maximum of 21 decibels, which is just a little more than a hum.

The humidity in the home is greatly reduced with this unit, so one must be careful with use of alternate humidity control systems. Also condensation on the pipes in winter and defrosting of the pipes is absolutely essential.

The filters have to be cleaned every couple of weeks using a vacuum cleaner or some such device.

The guarantees are 1 year for the installation work, 3 years for the unit and 5 years for the compressor. The various units are suited from areas as low as 50 sqm to 140 sqm.

When I looked at the aspect of Kampitie which has a cellar, the ground floor and the upper floor, and our need to keep the temperature at +27 C as Annikki's mother at the age of 87 needs to have this temperature, this unit would never be efficient as an alternate heating and cooling system with our low cost night energy heating system. If we were to use it only on one floor mainly to control the air quality and not the temperature, it could have some potential. But I have looked at the economics and it does not quite suit our present needs.

However, if anyone in a home suffers from allergies to dust and, say, cat fur, then this would certainly be a good investment.

Our daughter Joanna, in whose family a couple are plagued with allergies, this could be useful, although one would have to look whether there would be a significant impact in oil consumption as they have an oil heating system.

With oil prices sky-rocketing and expected to hit $ 100 per barrel early next year, such economies would certainly be worthwhile, as has been realised by the Swedish Government.

Single floor houses or apartments, where heating cost is not included in the rent or is the owner responsibility would certainly be the best market for this system.