On this page we have gathered the questions we are asked most often about heat pumps, with short answers. Each answer gives the essentials; where a topic goes deeper, you will find a link to the article that covers it. The answers apply to air source heat pumps with a water circuit, the most common type and the one we manufacture under the AD brand.
The basics
What is a heat pump and how does it work?
A heat pump is an electrically driven device that collects heat from the outdoor air through a refrigerant cycle and carries it into the building. In the outdoor unit the refrigerant takes heat from the air and evaporates; the compressor squeezes it and it heats up; in the indoor heat exchanger it gives that heat to the system water, then passes through a valve and starts again. Because it does not make heat by burning fuel, it delivers several times as much heat as the electricity it uses. We explain the cycle step by step in our article what is a heat pump.
Can a heat pump also cool?
Yes. A four-way valve in the circuit reverses the direction of the refrigerant, and in summer the unit rejects the heat it takes from the building outdoors. The chilled water goes to fan coils or to an underfloor cooling circuit. In buildings without fan coil pipework, the HİDREM indoor unit cools through wall-mounted air conditioner indoor units, and at the same time uses the heat removed from the rooms to warm the water in its tank. For coastal regions where the cooling load exceeds the heating load, we tuned the Vaha series for cooling efficiency as much as for heating.
What types of heat pump are there?
By heat source there are air, ground and water source units; by how they deliver heat to the building, air-to-water and air-to-air; by construction, monobloc and split units. Add to these hybrid systems that work with a boiler, and absorption heat pumps that run on heat instead of electricity. All AD units are air source units with a water circuit. We compare the differences in our article on heat pump types.
Climate, capacity and heating system
Does it work in very cold weather?
A unit chosen for the climate does. The capacity of an air source heat pump falls as the outdoor air gets colder, so you need to check what the unit delivers on the coldest days. AD's Boran series delivers 12–16 kW of heat and 65 °C water at −25 °C outdoors; the cascade Ayaz series produces 75 °C water at −30 °C. Poyraz is designed for −7 °C, for Marmara-type winters, and Vaha for +2 °C, for coastal climates.
What capacity does my home need?
Capacity is set not by floor area but by the building's heat loss at the design outdoor temperature: insulation, windows, the orientation of the façades and how the home is used all go into that calculation. If there is no calculation, the actual consumption of the existing boiler over recent winters is a good starting point. When comparing units, look not at the +7 °C figures in the catalogues but at the figures for your province's design temperature. We explain the order of steps in our article on heat pump selection.
Does it work with radiators and with underfloor heating?
It works with both; what matters is how hot the water needs to be. Underfloor heating usually runs on 30–40 °C water and is the most efficient system for a heat pump. In buildings whose insulation has been upgraded, or whose radiators were generously sized, 55 °C water is often enough. For radiators that need hotter water, Boran produces 65 °C and Ayaz 75 °C; Ayaz replaces a boiler on a radiator system without any changes. Whichever route is chosen, the lower the water temperature, the less electricity the unit uses.
Does it also make domestic hot water?
Yes. In AD systems, how hot water is made depends on the indoor unit: HİDRA and HİDREM carry an 80–140 litre tank in their cabinets, while the wall-hung HİD / HİT feeds an external cylinder of the same sizes. The number of people in the household decides the tank volume. In homes with solar collectors, the collector circuit is connected to the system through a second pump in the indoor unit.
Consumption and energy
How much electricity does a heat pump use?
Annual consumption is the heat the building needs in a season divided by the unit's seasonal efficiency, the SCOP. For example, in a house that needs 12,000 kWh of heat a year, a SCOP of 4 means about 3,000 kWh of electricity. The COP, by contrast, is the instantaneous ratio under a single condition; "A −7 / W 55" describes the point where the outdoor air is at −7 °C and the leaving water at 55 °C. You will find a worked example with clearly stated assumptions in our article on heat pump electricity consumption.
Can it work with solar energy?
In two ways. Photovoltaic panels on the roof cover part of the unit's electricity, and shifting its operation to sunny hours increases that share. Solar thermal collectors, on the other hand, heat the water directly; the HİDRA, HİDREM and HİD / HİT indoor units have a separate pump for the collector circuit. We explain the details in our article on solar energy with a heat pump.
What happens during a power cut?
A heat pump runs on electricity, so it stops during a power cut. In a well-insulated building the temperature falls slowly during an outage of a few hours, and in homes with underfloor heating the heat stored in the floor slab stretches that time further. Where power cuts are frequent, the unit can be supplied from a generator; the generator is then sized from the maximum power input in the unit's technical table.
Installation space and projects
Is a heat pump noisy?
The indoor unit is quiet: for the wall-hung HİD / HİT, the sound pressure measured at 1 metre is 18–23 dB(A). The main source of sound is the fan and compressor in the outdoor unit; each model's sound level at 1 metre is listed in its technical table. How loud it seems depends on where the unit stands, its distance from a bedroom window and the anti-vibration mounts. We go into the subject in our article is a heat pump noisy.
How much space does it take?
The outdoor unit stands in a garden, on a roof or on a large balcony; the Poyraz 12 outdoor unit measures 349 × 790 × 823 mm and weighs 64 kg. Indoors, the wall-hung HİD / HİT is the size of a combi boiler (510 × 1000 × 350 mm for the 8–12 kW models). The tanked HİDRA and HİDREM are floor-standing; depending on tank volume they measure between 500 × 1520 × 500 mm and 500 × 1750 × 500 mm, and since connections can be taken from the right, the left or the top, they fit into tight plant rooms too.
What is the difference between a heat pump and an air conditioner?
A split air conditioner is also a heat pump, but it releases heat directly into the room air (air-to-air). An air-to-water heat pump transfers heat into a water circuit; that lets it feed underfloor heating, radiators and the hot water tank, and heat the whole house from one unit. We compare when each makes sense for heating in our article air conditioner or heat pump.
Are there heat pumps for large buildings and greenhouses?
Yes. In villa, hotel, school and office projects where the 16 kW of the residential series is not enough, the 20–24 kW V series and the 28–56 kW W series outdoor units are used; in the W series several units work together to increase capacity. For greenhouses, housing estates and complexes with a central plant, the Mega central system covers 200–1,200 kW and is sized separately for each project. Its inverter control adjusts capacity steplessly between 10% and 100%, which matters in greenhouses where the load changes a great deal between night and day.
If your question is not here
If you have a question about your own project, send your province, heating system type and heat demand through our contact form, and our technical team will answer. For maintenance and service after installation, we work with our sister company Aktek Elektromekanik.
