An air source heat pump takes low grade heat from the outside air and upgrades it to a temperature useful for heating. Herambh Coolingz manufactures and supplies air source heat pumps for hot water and space heating duties in India, with the same engineering discipline applied to the company's chiller and cooler lines.
Because most of the energy delivered comes from the air rather than from the supply, an air source heat pump is one of the most efficient ways to generate heat with electricity, and it produces no combustion emissions on site.
How an Air Source Heat Pump Works
A refrigerant circulates through a closed loop. At the outdoor unit it absorbs heat from the air and evaporates; a compressor then raises its pressure and temperature; indoors the refrigerant condenses and gives up that heat to water or air before returning through an expansion device to start again.
Even cool outdoor air contains usable heat, which is why the cycle works through the year, though its output falls as the air gets colder.
Air Source Heat Pumps for Hot Water
In hot water duty the pump heats water in a cylinder or a flow-through exchanger. Because the water can be heated gradually and stored, the pump can run at its most efficient point for long periods rather than being forced to peak output.
This suits hotels, hospitals, hostels, canteens and process plants where a large volume of warm water is drawn each day and a steady heat input is the cleanest way to supply it.
Heating, Cooling and Combined Duty
The same cycle can be reversed to cool instead of heat, so an air source heat pump can provide cooling in summer and heating in winter. In some buildings it becomes the single source of both comfort duties, replacing separate systems.
In industrial settings the pump may be used to recover heat from a process that needs cooling, delivering useful hot water at the same time, which is about as efficient as heat generation gets.
Efficiency and the Seasonal Picture
The efficiency of an air source heat pump depends on the temperature difference it has to work across. A small lift from mild air into warm water is easy; a large lift into very hot water in cold weather is harder and less efficient.
Designers therefore look at performance across the seasons rather than at a single figure, and set the hot water temperature as low as the duty allows to keep the lift small.
Where Air Source Heat Pumps Fit
They suit sites with a fairly continuous heat demand, a reasonable ambient temperature and no cheap alternative fuel. They are less attractive where heat is needed in very large peaks from cold, or where very high temperatures are required for a short time.
As with any heat pump, good insulation of the hot water system and sensible set points protect the efficiency that the technology offers.
Components and Build Quality
A heat pump is only as good as its compressor, coils, controls and refrigerant circuit. Coils must shed water and frost cleanly, controls must balance performance against wear, and the cabinet must protect the unit outdoors for years.
Herambh Coolingz assembles air source heat pumps with components selected for long industrial duty, and arranges the layout so that air flow, service access and drainage are all practical.
Installation and Operation
Outdoor units need unobstructed air flow and enough space for service, and they should be sited where the air they discharge does not recirculate back into the intake. Pipe runs should be short, insulated and supported.
In operation, keeping filters and coils clean, checking controls and watching for changes in performance are all that is usually needed to keep a heat pump running near its designed efficiency.
Air Source Versus Other Heat Sources
Against electric resistance heating, an air source heat pump delivers more heat per unit of electricity. Against a boiler it avoids fuel handling and on-site emissions, and against ground source heat pumps it is simpler and cheaper to install because it needs no boreholes or ground loops.
The trade-off is that output falls in cold weather, so sizing must allow for it. Where that is understood and allowed for, the air source heat pump is a robust, low maintenance way to generate heat.
- Hot water generation for commercial buildings
- Heating and cooling from one unit
- No fuel storage or on-site combustion
- Best where heat demand is continuous
- Works with insulated storage to hold efficiency
| Parameter | Details |
|---|---|
| Heat source | Outside air |
| Cycle | Vapour compression, compressor driven |
| Delivered duty | Hot water, space heating, or reversible cooling |
| Efficiency | Depends on the temperature lift across the cycle |
| Installation | Outdoor unit with unobstructed air flow |
| Service | Clean coils and filters, verify controls and charge |
Discuss your heating load and site conditions with Herambh Coolingz, and we will advise on an air source heat pump suited to the duty.