Where is the best place for my Air Source Heat Pump?

Posted by Andi

One of the main questions we get asked is “Where is the best position for my Air Source Heat Pump?” We will always advise on the best positioning of where the pump should be positioned to provide optimum efficiency to your system however there are also other factors to consider besides mechanical efficiency.

In most houses, there will be multiple options of where the unit can be placed so we’ve put together this handy guide to help give an insight into the decision making of where to put your trusty Air Source Heat Pump

Open to the outside air…

Obviously, Air Source Heat Pumps rely on the outside air to function. The air can be as cold as around -20°C. However, they do require a good supply of free-flowing, ambient air. This means that they can’t be situated in a porch, facing a wall or in a generally tightly enclosed space.

We often get asked why we can’t put the Air Source Heat Pump inside, maybe in the loft or conservatory? The answer to this is because, after a few hours, the heat pump will have extracted all of the warmth from the trapped air, effectively turning this space into a freezer. This is why Air Source Heat Pumps need access to the free-flowing outside air. 

Accessing your Air Source Heat Pump…

The next thing to consider is accessibility. Air Source Heat Pumps are notoriously sturdy bits of machinery and are generally built to last a long time.

Air Source Heat Pump

However, your system will require an annual service to keep the system running smoothly and also to claim your Renewable Heat Incentive payments. This means that you will want your Air Source Heat Pump to be easily accessible to an engineer if work needs to be done on it.

Placing a pump in an awkward location may inhibit an engineer from performing all of the necessary checks that your system needs. The ideal locations are ones on the ground level where the engineer can easily access all sides of the Air Source Heat Pump with room to freely move and remove the outer panel. 

Close…but not too close…

Thirdly is the proximity to your home. It is better to have the Air Source Heat Pump on the floor immediately outside your home’s outer wall. This is because less pipework is required to connect the unit to the water cylinder, so there is less opportunity for heat to escape in the transfer stage.

You also want to be mindful of the defrost cycle during winter. During sub-zero temperatures, Air Source Heat Pumps enter a “Defrost Cycle” which thaws out any forming ice or frost on the outside unit, this can result in the thawed water freezing over so be cautious if you’re wanting to place the unit near any frequented path.

You will also want to ensure that your Air Source Heat Pump has free airflow at the back of the unit and does not sit flush to the wall it’s attached to. If it is then cold air that has been passed over the heat transfer coils will blow back into the unit, causing it to lose its efficiency. 

Preventing noise…

Next, we have to factor in the best place for your pump to prevent noise irritation. Contrary to some peoples beliefs, Air Source Heat Pumps are actually extremely quiet. The Mitsubishi Ecodan actually has a sound pressure level of 45dB at one meter, which for reference is 1dB louder than the average library and quieter than the average dishwasher which sits at around 70dB and the average gas boiler which sits at around 60dB. So in reality, it’s like having a gas boiler… bolted to the outside of your house…that isn’t bad for the environment.

Despite this, it is always wise not to situate your Air Source Heat Pump directly beneath a window of a frequently used room such as a bedroom or a living room as you may hear a faint hum during winter when the Air Source Heat Pump has to speed up due to the lower temperatures. 

General “no go” areas…

This last point is more down to common sense, do not place your Air Source Heat Pump in a location that you think could be hazardous. Air Source Heat Pumps are fantastically resilient pieces of machinery, however, they work best when they’re not exposed to flooding, leaky guttering, sinking ground conditions and other obvious locations that could potentially inhibit the smooth running of your heating system.

Other than these obvious places there are many places that your Air Source Heat Pump can be placed on your property to ensure that you have a fully efficient system in a location where it will not be an inconvenience.



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