AERMEC, a HVAC company headquartered in Italy has been contributing to the evolution of heat pumps with its iconic multipurpose unit range called NRP.

NRP stands for “No Refrigerant Pipes”, a pretty clear statement of the concept with which AERMEC have been developing these machines: providing a hydronic (better) version of the VRF systems.

Multipurpose units are able to provide cooling, heating and also produce Domestic Hot Water (DHW) for the needs of many diverse applications such as hotels, office buildings and house complexes.

Nowadays direct expansion systems are giving way to the hydronic systems, which are well appreciated for their outstanding energy efficiency, flexibility in installation and overall very low operation costs. These reasons determine the low payback time of such hydronic systems, not mentioning the environmental benefits gained.

Over the last 20 years in Europe, the multipurpose heat pumps (also called 4 pipe heat pumps) have taken the lead not only for those applications in which there is a contemporary need for space heating and cooling in the middle seasons (4 pipes water systems) [typical of well insulated buildings with big glass surfaces of continental climates] but also for those applications in which there is a contemporary demand for cooling and domestic hot water.

The latter is the typical load profile for Hotels, Hospitals and many other applications in hot/warm climatic countries which is why the multipurpose heat pumps are recently winning a great success in South Asia. Typically, in these areas cooling is needed in every building for most time of the year. There is also a growing demand for domestic hot water for use in showers, laundry, kitchen and other applications.

Aermec is one of the leading HVAC equipment manufacturers in Europe and one of the pioneers in the multipurpose heat pump development. With a great experience in this field, Aermec now offers a full range of multipurpose heat pumps from 12 TR to 270 TR.

Thanks to this kind of technology, the domestic hot water is produced for free whenever there is contemporary need for cooling.

What is a multipurpose heat pump, or 4 pipes heat pump?

We define multipurpose unit a heat pump with total heat recovery which has a particular architecture of refrigerant circuit coupled with a specific and dedicated management logic, so that such unit is able to satisfy simultaneously and independently cooling and heating demands.

AERMEC Heat Pumps: Simultaneous Heating and Cooling

The unit control takes care of switching the refrigerant valves and doing everything that must be done in order to satisfy the cooling and heating demand measured by the water temperature probes of the machine.

It is clear that this technology is game changing if we compared it with the traditional chiller equipped with heat recovery. The chiller equipped with heat recovery is only able to produce heating while cooling, and the heating capacity available is dependent upon the cooling capacity demand. A back up source of heating is mandatory in order to meet the heating requirements when there is low or no cooling demand.

With a multipurpose unit instead, we are able to satisfy independently the heating and cooling demand in all possible combinations, minimizing also the global footprint required for the installation (no back up required).

Global Efficiency

There is another great plus: Global Efficiency.

In Asian countries, we see that most of the time water cooled chillers are preferred compared to air cooled chillers as the efficiency achievable is much higher.

In reality, that efficiency is much higher only on paper because we need to take into account the fact that we have cooling towers with fans working on the condensing loop, pumps, water consumption and water treatment as well as the additional design, operation and installation costs.

Providing heating via heat recovery with a water cooled chiller would mean investing in many equipment that will be used only partially. This is because whenever there is heating demand, the chiller will be condensing in the heating loop, and thus not using the condensing loop with cooling towers.

Therefore the air cooled equipment will be of much easier and quicker installation, with less maintenance costs and flexible in operation.

Efficiency wise, the amount of energy saved by providing heating with contemporary cooling is huge, as in most of the South Asian countries cooling is required throughout the whole year. It is easy to realize that the heating will come free of cost for the major part of the year.

Whenever the multipurpose heat pump is working in recovery mode (producing chilled water and hot water), the unit is working like a water cooled unit.

The benchmark for energy efficiency is nowadays represented by water cooled magnetic bearing centrifugal chillers. They can achieve a COP in cooling that usually goes from 0.6 to 0.7 kW/TR (5.1 to 5.9 W/W).

When an AERMEC multipurpose heat pump is working in total heat recovery, and when heating demand is equal to cooling demand, its global efficiency (called TER which stands for Total Efficiency Ratio) goes from 7.58 W/W to 7.85 W/W

This means the multipurpose heat pump is able to transform the electrical input power into useful cooling and heating energy with a more convenient ratio than a magnetic bearing chiller transforms its electrical input power into cooling capacity, and that is because a big portion of energy is lost throughout condensation.

In summary, after many years of close collaboration with designers and consultants all over the world, AERMEC has been able to prove the advantages of the multipurpose heat pumps which can impact the total life cycle cost of an HVAC installation with savings of up to 20% compared to the traditional solution of chiller plus boiler.

Use the form below to contact AERMEC if you need more information about this product.

Enquiry on AERMEC Multipurpose Heat Pumps

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About AERMEC – AERMEC is a leading global brand within air conditioning, offering products, services and green solutions which perfectly meet the most demanding market requirements.

Aermec S.p.A.
Via Roma, 996
37040 Bevilacqua (VR) Italy
Phone: (+39) 0442 633 111
Fax: (+39) 0442 93577

Editorial Contributors
Alora Bopray

Alora Bopray

Staff Writer

Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today's Homeowner. She earned her bachelor's degree in psychology from the University of St. Scholastica and her master's degree from the University of Denver. Before becoming a writer for Today's Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she's not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.

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Roxanne Downer


Roxanne Downer is a commerce editor at Today’s Homeowner, where she tackles everything from foundation repair to solar panel installation. She brings more than 15 years of writing and editing experience to bear in her meticulous approach to ensuring accurate, up-to-date, and engaging content. She’s previously edited for outlets including MSN, Architectural Digest, and Better Homes & Gardens. An alumna of the University of Pennsylvania, Roxanne is now an Oklahoma homeowner, DIY enthusiast, and the proud parent of a playful pug.

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