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What is a Heat pump?

A heat pump is a home appliance (similar to a fridge freezer) that heats and cools the atmosphere in the home. It offers home owners comfort that is normally reserved for high-rise office buildings, five-star hotels and executive apartments. It heats, cools, dehumidifies and continuously filters the air of dust and other impurities. It also circulates the air - without heating or cooling - to eliminate stuffiness. A typical heat pump is two units - an indoor unit, and an outdoor unit. For this reason, they are often called "split systems". Many have remote controls for maximum convenience.

How does it work?

A fridge transfers heat from its food compartment to the coil at the back. Like a fridge, it can be reversed so that the heat flow goes the other way. Heat pumps transfer heat from outside air into the home in winter, and transfers heat from inside the home to outside air in summer.

But how can it heat the home and winter when it is freezing outside?

A home freezer can take the temperature of its food compartment below 0°, in fact as low as -6°C. If it can remove heat from inside a freezer to below 0°, the same process - used in the heat pumps - can extract enough heat from cold outside air to warm the home. Although our body's feel cold at these low temperatures, there is still a lot of heat energy in the outside air at 0°C.

What size will I need for my home?

Every home is as individual as its owner. The key to selecting the right size heat pump for your home is an accurate estimate of the heat that will need to be transferred into your home in winter for heating, and out of your home in summer for cooling. This needs to be carried out by an experienced and qualified specialist like Excel Refrigeration and Air Conditioning Ltd.

What factors will affect the size of heat pump I need?

The amount of heating needed will depend on the heat loss through walls, windows and roofs. To minimise heat loss and before you invest in the heat pump, it is always a good idea to properly insulate walls and roofs first. In particularly cold climates double glazing windows will insulate them and keep heat loss to a minimum. By insulating first, the size of heat pump selected will generally be smaller and therefore be cheaper to install and run.

The northern aspect of the home is also an important factor. North facing rooms will catch the sun better and more generally need less heating. Conversely, South facing rooms tend to be colder and will need more heating.

Do heat pumps take up a lot of room?

No. Heat pumps are designed to be unobtrusive in size, neutral decor and low noise levels. There are also different types of heat pumps, from a stylish through the wall packaged unit to different varieties of split systems. The least obtrusive is a ducted split system. This can be hidden in the ceiling or under floor and only the grilles for distributing the air are visible.

How much does cost to buy and install a pump?

As stated before, every home is as unique as its owner. The installed cost of the heat pump will therefore be unique for each home and will depend on the size and type of heat pump installed. As an example, a standard three-bedroom 100 m2 timber framed New Zealand home may use a 5.5 KW hi-wall split system heat pump to warm the lounge, dining and kitchen as one open plan area. This type of installation would currently cost just over $3000 plus gst to install. A very broad guide to heat pump installed cost is $60-$100/m2 plus gst of served area. Served area is the area being heated and excludes laundries, garages, toilets and other utility areas in the home.

How much does cost to heat my home with a heat pump?

To answer this question the amount of heating that is currently necessary will need to be known. For the purpose of explanation, assume 5KW of heating is needed. Electrical heating appliances are normally 100% efficient so for 5 KW of heating one will need to pay for 5 KW of electric energy. Gas heating appliances are less than 100% efficient. For discussion, let's assume that they are 90% efficient. This means, to gain 5KW of heating, one has to pay for 5.6 KW of gas energy. Although gas may be cheaper per KW, one has to use more of it to produce the same heating effect. Heat pumps transfer heat from outside air and in this way produces two to three times more heat. Its efficiency - if it can be called that - is 200% to 300%. This means for 5 KW of heating, one will only pay for around 2 KW of electric energy. Heat pump heating is roughly a third of the cost of electric heating and about half the cost of gas heating.

How can a heat pump be cheaper to run when it has more moving parts?

A heat pump uses electricity to transfer heat. Electric heaters convert electric energy to heat energy and are thereby limited by the amount of electricity used. A heat pump has no such limitation and can transfer twice to three times the heat from outside air than can be converted from the electricity at uses.

Are heat pumps noisy?

No, they are generally not noisy. The source of the noise in a typical heat pump is air impinging on the grille as it is forced out of the unit. Air noise is marginally higher than ambient background noise and is usually not distracting.

Do they dry the air: like on an airplane?

Heating or cooling air changes its characteristics. Heating air increases its ability to carry moisture and suspension by reducing its relative humidity content. This is the same process used in clothes dryers. Cooling air causes the moisture in the air to condense out of suspension. This reduces the absolute humidity content of the air and is the process used in the humidifiers. Either way, reducing moisture in the home is beneficial by discouraging mould and mildew by producing a healthier living environment.

Are they reliable?

Yes. Heat pumps are reliable. They use the same process as the home fridge or freezer and have the same level of dependability and useful life expectancy.

How easy are they to repair?

Provided the service person is experienced and qualified, repairing heat pumps is as straightforward as repairing the fridge or freezer. For repairs, talk to Excel and Refrigeration and Air Conditioning Ltd.

Do they need servicing?

Like cars, heat pumps should be regularly serviced for optimum operation. This involves cleaning the air filter and perhaps checking that the refrigeration charge is correct. It would be a good idea to service the pumps just before the beginning of each extreme season i.e before winter and again before summer.

How are heat pumps better than other forms of heating?

Apart from being cheaper to run, heat pumps offer other benefits that heating only systems cannot.

1) Heat pumps don't burn oxygen or create stuffiness like open fires do. They are designed for all year round comfort, not just for four months during winter.

2) They produce low-density heat which is safer for children and elderly, unlike fires, oil filled or electric fan heaters.

3) They are unmatched for convenience and ease-of-use.

4) They do not pollute their atmosphere with the products of combustion, and they use ozone friendly refrigerant.

All in all, heat pumps offer the best investment in home heating and comfort. 
Taranaki Airconditioning Heatpumps

Excel Airconditioning

The leading heatpump and refrigeration specialist in Taranaki New Zealand