Air source heat pumps are becoming the heating solution for homeowners who want to cut energy costs while reducing their environmental impact. Whether you are thinking of switching your old fashioned HVAC systems or just need to know more about how this technology operates, then you are at the right spot.
How this guide will help
This guide is for home owners, property managers who might have been interested to learn more on sustainable heating options. You do not require an engineering degree to keep up with us, we will simplify the complicated science for you.
We shall begin with the basic concepts that render air source heat pumps so effective, such as how they obtain warmth through the outside air, even during cold conditions. You will also learn the various system types in the market. At the conclusion of this guide you will be in a position to make an informed choice regarding whether to install air source heat pump technology in your house.
Air Source Heat Pump Fundamentals
What Makes Air Source Heat Pumps Different from Traditional Heating Systems
Your old fashioned heating system burns fuel or produces heat by electric resistance by starting with scarcity. An air source heat pump operates in an entirely different way.
- It extracts heat that already exists in the outside air even when the air contains temperatures that are below freezing.
- This basic distinction converts heat pumps into highly efficient devices since they are not producing heat; they are just transferring it.
- With the gas furnace you are only 80-95 percent efficient in converting fuel into heat. 4.
- Your air source heat pump can deliver 200-400% efficiency because it’s harvesting free heat energy from the outdoor air. You receive many units of heat to your home in exchange for a unit of electricity consumed.
Heat Transfer Process
The significant variation is in the heat transfer process.
- Your furnace combusts to provide warmth, and your heat pump absorbs the heat of outdoor air and concentrates it inside in the refrigerant.
- This works the other way around during the summer where the same system can be utilized to cool your home by extracting the heat and taking it out of the house.
- You will also see operational variations. Conventional systems switch on and off many times, and this results in a rise and fall in temperature.
- Your air source heat pump operates more reliably at variable speeds, keeping indoor temperatures the same with less energy expended in general.
The Hp Components
There are four vital components in your air source heat pump system that help to circulate heat effectively.
- The compressor is found in the outdoor unit and pressurizes the refrigerant in order to raise its temperature.
- This hot condensed refrigerant is sent to your indoor unit’s condenser coil where it transfers heat to the air in your home.
- The growth valve operates the flow and pressure of the refrigerant enabling it to expand and warm up again as it moves back to the outside unit.
- This is then completed by your outside evaporator coil absorbing heat in external air, even when the weather is cold.
Importance of Compressor
The type of compressor is very important to the efficiency of your system. Variable speed compressors increase or limit delivery to exactly match your heating needs at home consuming only the energy necessary. This is unlike single speed compressors that operate at full capacity irrespective of the needs that exist to heat.
Indoor Air Handler
Your indoor air handler has variable speed fans which maximize the airflow over heating coils. This accuracy guarantees optimum heat removal within the refrigerant and reduces the amount of energy used in the circulation of air.
The reason Air Source Technology works even during cold weather
You might wonder how your air source heat pump extracts heat from freezing outdoor air, but physics makes this possible.
Important: Any temperature above absolute zero (-459 deg F) has heat energy contained in the air. At even -100 degrees F, outdoors there is much thermal energy present in the air that your heat pump can extract and focus on.
The refrigerant in your system boils very low, almost at -15degF to -25degF. This implies that refrigerant will be in liquid form until it is exposed to air with a higher temperature than its boiling point where it will absorb the heat energy and evaporate. This change of state enables heat uptake even in the conditions when the outdoor temperatures appear remarkably low.
The Science Behind its Operation
The process of how Refrigerant Removes Outdoor Air Heat
Heat pump technology works with your air source heat pump by taking advantage of an ingenious refrigerant property.
Step by Step
- It can absorb heat when the air outside feels frozen cold. Your refrigerant has a significantly lower boiling point than water which is normally -15degF to -40degF.
- This implies that it is able to draw out thermal energy in the temperature of the outdoor air which will make you tremble.
- Liquid refrigerant passes through the outdoor coil (evaporator) and it comes in contact with warmer air than its boiling point.
- That air has sufficient heat energy to boil the refrigerant and turn it into a gas even on a winter day of 20degF.
- When it transforms, the refrigerant takes the heat of the air around it and cools down the air and warms up.
- You will see that your outdoor unit has a fan that pulls air through these coils and ensures maximum contact between refrigerant and available heat.
- The more air travelling over the coils, the greater the heat that your system will absorb.
- This works on a continuous basis with your heat pump actually extracting the thermal energy out of what is considered by you as cold air.
Four-Stage Cycle
Your air source heat pump operates on a continuous four stage refrigeration cycle that moves heat from outside to inside your home.
Evaporation
A cold liquid refrigerant flows to the outdoor evaporator coil and it takes on heat of outside air and it converts into low pressure gas. This is despite the cold weather since the boiling point of the refrigerant is very low in comparison to the outdoor air temperatures.
Compression
This low pressure refrigerant gas is picked by the compressor and compressed tremendously. Compression of a gas increases its temperature a great deal as the pumping of a bicycle tyre does, and the pump heats up.
Condensation
This warm pressurized gas is directed to your internal coil (condenser) where it gives up its heat to heat the air in your home. The refrigerant loses this heat energy and condenses into a liquid again.
Expansion
The liquid refrigerant is made to flow through an expansion valve which decreases its temperature and pressure enabling it to begin the cycle once more. This is the circle and the process goes on and on.
Why are Heat Pumps More Energy Producing than a Consuming System?
Your air source heat pump achieves something that seems impossible. It delivers more heating energy to your home than the electricity it consumes. This is a magic that appears to be there since your heat pump does not generate heat but relocates already existing heat.
Important: The ratio in this case is the Coefficient of Performance (COP) of the heat output/electrical input. A standard air source heat pump has a COP of between 2.5 and 4.0 which is, one unit of heat per every 2.5 to 4 units of electricity. Compare with electric resistance heating whose COP is equal to 1.0.
Efficiency
This efficiency is achieved by your heat pump using electricity simply to drive the compressor, fans and controls – not to produce heat. The real thermal energy is provided out of the air outside. Vast quantities of heat energy can be extracted even when the weather is at 0degF.
Note: The colder it gets the heavier your system works and the lower your COP, but you are still transferring heat, not making it.
Types Of Air Source Heat Pump
Space Heating to Air Heat Pumps
Thermal energy is exchanged between your indoors and outdoors using refrigerant in your air to air heat pump system.
Operation
The systems operate by drawing heat outdoors and pumping it straight into the interior air of your home during heating operation. The opposite happens when you need cooling whereby warm air is drawn out of your home and air is pushed outside.
Air to air systems will work especially well since they can provide conditioned air in your existing ductwork or with separate indoor units.
During Winter
As long as you are operating during winter, your system draws ambient heat energy from outside air, even when temperatures are below freezing, and focuses that energy to heat up the inside areas. Refrigerant collects the heat in low temperatures outside and is compressed and releases the concentrated heat in your home.
Your air to air heat pump will work best when outdoors it is above 25 degree F, but new models can work quite a bit colder.
Feature | Benefit |
Dual season operation feature | Heating and cooling from one system |
Direct air delivery feature | Fast temperature adjustment |
Energy efficiency feature | Lower operating costs than traditional HVAC |
Find Out How Much an Air Source Heat Pump Really Costs
Home Comfort with Air to Water
Your air to water heat pump taps the heat energy in the outside air and moves it to water circulating inside your hydronic heating system. You will have this system linked to radiant floor, baseboard radiators or fan coil units that circulate warm water in your living areas. These systems also warm your home hot water supply thus providing you with overall control of comfort.
Once you install an air to water system, you can enjoy the benefit of zone by zone temperature control that allows you to make various areas of your home as comfortable as you would like them to be. Your system circulates hot water in different circuits so that you can keep the bedrooms, living areas and bathrooms at various temperatures on your choice and use schedule.
Duct and Ductless Installation
Deciding whether to have ducted or ductless will be dependent on the infrastructure that exists in your home and your comfort needs. Ducted systems are tied into your existing central air delivery system, and existing vents and registers are used to supply conditioned air throughout the home. You will keep all the air delivery habits with you but upgrade to efficient heat pump technology.
Ducted System Advantages
- Takes advantage of the existing ductwork system.
- Has a centralized filtering of air.
- Brings air to the entire house.
- Hides the in door units.
Ductless System Benefits
- Per-room temperature control.
- None of the ductwork energy loss.
- Simple to install in duct free homes.
- Silent performance with high-tech indoor units.
These approaches have a wide variation in the complexity of their installation. Ducted systems tend to use less noticeable equipment, but can modify ductwork. Ductless systems are quicker but install indoor units in your living areas where you will be able to see them every day. Have a look at Air Source Heat Pumps Location Rules.
Get Your Assistance from Home Energy Guide
Here at Home Energy Guide, we always strive to take UK residents on a journey through the confusing landscape of home heating and energy efficiency. We aim to serve you by giving you clear, unbiased and professional guidance enabling you to make informed judgments regarding your property. You can use our full guides and resources to find the most sustainable and cost-effective answers to your home, whether it be a new heating system, such as an air source heat pump, how to save on your bills, or what grants and financial assistance are available.
Ready to start? Click the ‘Check Eligibility‘ button to see if you qualify for the Air Source Heat Pump Grant.
Your journey to a warmer, more energy-efficient home begins now.
Frequently Asked Question (FAQs)
That is the great question, and the answer is, yes, certainly! Although the upfront price is more expensive than a boiler, a heat pump is a long term investment. It is astonishingly efficient and consumes a lot less energy to warm your house, which also translates to big money saved in the long run.
It is an extremely widespread concern and the answer is yes! Modern air source heat pumps are brilliant at what they do. They are uniquely created to remove the heat off the air even when the temperatures fall way below the freezing point keeping your home warm and cosy throughout the entire winter.
It is a professional job but nothing as disruptive as you would imagine. A skilled installer will do it all, including installing the outdoor unit, and linking the inside system to your heating. They will ensure that the process is as hassle free as possible to you.
