Air to Water Heat Pump – How Does It Work

If you live in a moderate climate, air to water heat pumps can efficiently heat and cool your home. An air to water heat pump can provide a home with up to three times the amount of thermal energy it consumes after proper installation. This may occur because, unlike conventional combustion heating systems, heat pumps transfer heat rather than changing it into a different form.

Despite being widely used in the United States and Scandinavia, air-source heat pumps typically do not function well in subfreezing temperatures. Air to water heat pumps might not be the most economical option for all of your heating needs in regions with subfreezing winter temperatures. This problem could be resolved if a gas heating system were installed as a backup. However, air to water heat pumps specifically created for cold climates began to show promising results.

You can watch the video below to learn more about air to water heat pumps and how they differ from air to air heat pumps. In it, we compare the two air source heat pumps based on their technology, price and installation, effectiveness, and potential cost savings.

What is An Air Source Heat Pump?

An air source heat pump, also known as an air-to-water source heat pump, uses heat exchangers to turn outside air into water, which then heats your rooms’ radiators or underfloor heating. For your hot taps, showers, and bathtubs, it can also heat water that is kept in a hot water tank.

A fluid absorbs heat from the surrounding atmosphere. After passing through a heat exchanger, this fluid enters a heat pump, which raises the temperature and transfers the heat to water.

How Do Air to Water Heat Pumps Work?

Effective energy savings and lower carbon dioxide emissions are provided by a complete, contemporary heat pump system. Due to the indoor unit’s integrated immersion heater, circulation pump, hot water heater, and climate control system, heat production is both safe and affordable. The heat is brought in from the outside through an outdoor unit, where it is transferred to the indoor unit by a closed piping system of refrigerant. The criteria by which heat is transferred can be simplified as follows:

1. An outdoor unit takes in heat from the ambient air and transfer it to a coolant
2. A compressor increases the temperature of the coolant
3. The coolant transfers the heat to a hot water reserve tank via a heat exchanger
4. Hot water is circulated to radiators and faucets
5. Cold water is transported back to the tank
6. The coolant is transferred from the tank to the outdoor unit

If the aforementioned procedure were reversed, the outdoor unit’s refrigerant would absorb the heat from the water and release it into the atmosphere, allowing the heat pump to cool the home as needed.

Types of Air-Source Heat Pumps

Below is a description of the various types of air source heat pumps.

Ductless Vs. Ducted Vs. Short-Run Ducted

Construction is minimal for ductless applications because all that is needed to connect the indoor heads and outdoor condenser is a three-inch hole through the wall. Additions frequently have ductless systems installed.

Ductwork is all that is used in ducted systems. You might take into account this system if your home already has a ventilation system or if it will be a new construction.

Traditional long ductwork, or short-run ducted, only passes through a small portion of the house. Other ductless units are frequently used to supplement short-run ducted in the rest of the house.

Split Vs. Packaged

The majority of heat pumps are split systems, meaning that they have an inside and an outside coil. Connected to the indoor central fan are supply and return ducts.

In packaged systems, the fan and coils are typically located outside. A wall or roof-mounted ductwork system distributes heated or cooled air to the interior.

Multi-Zone Vs. Single-Zone

Single-zone systems have one outdoor condenser paired with one indoor head for a single room.

Two or more indoor coils may be connected to one outdoor condenser in multi-zone installations. Multi-zone indoor coils vary by size and style and each creates its own “zone” of comfort, allowing you to heat or cool individual rooms, hallways, and open spaces. This distinction may also be referred to as “multi-head vs. single-head” and “multi-port vs. single-port.”

Is An Air Source Heat Pump Right for Me? 

With tens of thousands of installations throughout the UK, air source heat pumps are the most popular type of domestic heat pump and suitable for many different types of homes. Before deciding whether a heat pump is the best option for you, you should take a few factors into account.

How Much Does An Air Source Heat Pump Cost?

The price of an air source heat pump varies depending on the size of the heat pump, the size of the property, whether it is a newly constructed or existing property, and whether you need to alter the way you distribute heat throughout your property. We advise speaking with at least three installers to get a quote for your heat pump system so you can get the best idea of what to expect to pay for your home. Typical costs range from around £7,000 to £13,000.

Will a Heat Pump Save Me Money on My Energy Bill?

How your heat pump is built and used will determine its operating costs. Depending on the system you replace, you may save money on your energy bill.

The table below illustrates the annual savings that could be realized by installing a typical air source heat pump in a typical, detached, four-bedroom home. It also includes any recommended radiator upgrades.

Visit our comprehensive guide for more details on how to maximize your savings and make the most of your heat pump.

Performance Issues With Heat Pumps

Low airflow, leaky ducts, and the wrong refrigerant charge are all potential issues with heat pumps. For each ton of the heat pump’s cooling capacity, there should be a flow of 400 to 500 cubic feet per minute (cfm) of air. If airflow is much lower than 350 cfm per ton, performance and efficiency suffer. Although technicians can increase airflow by cleaning the evaporator coil or turning up the fan, ductwork modifications are frequently required. See insulating ducts and reducing energy losses in ducts.

At installation and during each service call, refrigeration systems should be checked for leaks. Packaged heat pumps are typically correctly charged with refrigerant at the factory where they are made. Split-system heat pumps, on the other hand, are charged in the field, which occasionally results in either too much or too little refrigerant. Split-system heat pumps typically perform very close to the SEER and HSPF ratings listed by the manufacturer when the refrigerant charge and airflow are correct. However, too much or too little refrigerant lowers the effectiveness and performance of a heat pump.

Air-Source Heat Pumps Advanced Technologies

Advancements are always around, just like in every new area of technology. There isn’t an exception in the heat pump industry. That is why three new systems have risen enough to attract interest:

• The Reverse cycle chiller (RCC) – it allows you to choose from a wide variety of heating and cooling distribution systems, such as radiant floor systems and forced air systems with multiple zones. This enables you to work as efficiently as possible, regardless of the weather. For homes that use only electricity, a RCC system is advised.
• The Cold Climate Heat Pump – it features a two-speed, two-cylinder compressor for efficient operation, a back-up booster compressor that allows the system to function efficiently even at -9.4. It also disposes of a plate heat exchanger, which is also known as an “economizer” that further extends the performance of the heat pump to below -18 degrees celsius. Consumers who live in their homes will soon have access to this system as well.
• The All Climate Heat Pump – the manufacturer stated that it can operate even in the coldest winter conditions without derivative heat, maintaining a pleasant indoor temperature even when temperatures outside drop below -20. Between 25 and 60 percent less money would be spent on heating and cooling thanks to this heat pump. The All Climate system includes heating as a primary function, so the initial costs are high. However, the system keeps getting better, so the energy savings would more than make up for the initial cost.

In terms of green and clean heating systems, the air to water heat pump is the way of the future. The benefits can be seen a year after your investment has been made, and even though the initial costs are high, you won’t look back with regret.