The heat periods in summer are getting hotter and longer. The nights are too warm and rob people of sleep. As real estate owners, you want your tenants to feel as comfortable as possible. Luckily, you can easily mount cheap air-conditioning units to your wall and be done with it. But does it always have to be air conditioning? Sure, it’s certainly the most convenient system and a quick solution. But as the world struggles to counteract global warming, the relatively high percentage of CO2 emissions from air-conditioning is worth taking a closer look at. Especially, when the general public is increasingly becoming aware of this topic and has started to pay attention to eco-friendly alternatives. There are already alternatives to air conditioning in homes that come with fewer emissions, less maintenance and are less stressful to the human body.
Surface Cooling Instead of Air Conditioning
An air conditioner blows out cold air and cools the room. Undercooled rooms and too large temperature differences between inside and outside are the results. This can be an enormous feat for the body. The circulating cold air creates a draft in the room, which can lead to colds and tense muscles. Gladly, we live in times where an air conditioner isn’t the only solution anymore to make the summer heat bearable.
Surface cooling has been around for some years now, but somehow doesn’t get the attention it deserves, despite it being as effective as conventional Air-conditioners. It even offers more elegant and contemporary design possibilities. In contrast to conventional air conditioning systems, surface cooling cools the bodies in the room and not the air. Surface cooled rooms even remain free of drafts, while simultaneously minimizing the potential danger of bacteria. A benefit to many, suffering from allergies. Cooling rooms over walls, floors or the ceiling is also noiseless and can even run overnight during the hot summer days.
Just take Variotherm’s product line for instance: With a water-cooled surface cooling system for walls, floors or ceilings, they present one of the more pleasant and healthier alternative air conditioning solutions. Structurally tested gypsum fiberboards serve as a cooling surface. Aluminum multilayer composite pipes, integrated into the wall, circulate cold water around 16 ° C and cool the surfaces. Thanks to the radiation exchange, any surplus heat inside a room is released from the environment to the cooling surfaces. The result is a pleasantly cool indoor climate without causing draft or making any noise.
Furthermore, the energy conservation rate in surface cooled environments is better than with conventional air-conditioners. Each additional degree of room temperature saves 10% on energy costs. While an Air-conditioner has to be cooled down to 23°C on hot days, you will feel perfectly comfortable at 26°C with a surface cooling system. This saves up to 30% energy costs.
A 2011 study, done by the ASHRAE Foundation, cemented this conclusion by doing the world’s largest side-by-side comparison of radiant cooling and forced air cooling. After two years, they concluded that radiant systems had used 34% less energy compared to variable air volume systems.
On top of that, the initial cost was also lower in the radiant system and a survey conducted of the building’s occupants found that thermal satisfaction was higher in the section that utilized the radiant cooling system. – Robert Cubick (Uponor)
Another plus of surface is the ability to also heat rooms in winter. Instead of cold water, you have warm water flowing through the pipes to evenly heat the room, which further contributes to reducing life cycle costs.
Compared to conventional air conditioning systems, this type of cooling produces about 50% less CO2 and can even lower your electricity bill by 35%. At present, mainly large-scale buildings such as hospitals, public buildings or hotels are supplied with district cooling. However, many governments are working hard to be able to offer this technology in the private customer sector in the future. When planning and developing new real estate projects, this alternative to air-conditioners is definitely worth looking into.
The effort for less emitting cooling systems is further pushed on by French energy giant ENGIE by signing a major 22 Million EUR deal to develop and operate a series of district energy schemes in the UK, over the next 40 years. ENGIE, a company that is utilizing the benefits of ConTech, will design, build, operate and maintain the schemes for Newcastle City Council in the northeast of England. Utilizing natural gas-fired CHP (combined heat and power), the plan is to provide energy, via a network of pipes, all businesses, and homes with affordable heat. Additionally, chilled water and a private wire electricity network will provide cooling and electricity to the non-residential customers.
One might think that in colder countries, like in the UK or any of Europe’s northern countries, this might not play a big role but with the worlds, ever-present CO2 problem, finding ways to reduce its emissions to counteract global warming, this adds up. For more context just look at Europe’s cooling demand:
Particularly for Europe’s warmer countries, scaling district cooling technology can certainly have a significant effect on CO2 emissions. Sadly, the middle and the northern European countries are much further regarding district cooling than their southern neighbors.
The Helsinki district cooling system, for example, uses their CHP power generating unit’s surplus energy from warmer summer days to run absorption refrigerators for cooling purposes during hot summer days, greatly reducing electricity usage. In the winter periods, cooling is achieved more directly using cold seawater. The adoption of district cooling is estimated to reduce the consumption of electricity for cooling purposes by as much as 90%. The idea is now being adopted in other Finnish cities, as well as in Sweden.
Vienna has been offering district cooling since 2007. Until 2024, its main supplier Wien Energie wants to invest further 65 million Euros into this technology. At present, a total of 16 district cooling plants with a total output of 130 MW ensure that certain households remain cool even on hot days. The cities aim is to supply the entire city center with district cooling. Which makes sense, because, for reasons of monument conservation, space for heat exchangers is rare. Besides, the classic air conditioning systems have one major disadvantage: they give off heat to the environment. In some big cities so much, that the nights can be one or two degrees warmer.
The cost-effectiveness of thermal heat pumps
In general, heat pumps enjoy quite a good image. Be it an Air-source, Ductless mini-split, Geothermal or Absorption heat pump, they pride themselves of their small carbon footprint. They are low in maintenance and even combinable with solar collectors and photovoltaic panels. Although the view of many handymen to heat pumps is ambivalent, their economical efficiency can be quite controversial. To achieve great efficiency, various factors play together. Manufacturers often base their product description on optimal conditions. In practice, then occur higher electricity costs than calculated in advance. Especially in poorly insulated old buildings with radiators that require a high flow temperature, heat pump heating can hardly be operated economically. Not even if subsidized by the state, their eco-balance in old buildings is still rather moderate.
But utilized in new buildings, it’s a completely different story. If floor and wall heating, as well as controlled house ventilation, are in use, heat pumps make a lot of sense. Heat pumps work efficiently in modern, well-insulated houses with underfloor heating, making them environmentally friendly. Particularly, when the house itself generates electricity and/or receives the electricity from a green electricity provider. Given favorable geological conditions, the high cost of a heat pump system will be amortized over approximately ten years through government subsidies and low operating costs.
Air-Conditioning Alternatives for Residential Real Estate
Strangely enough, the aforementioned alternatives to air-conditioning are rarely utilized in private households. This seems due to a rather low presence within the public eye. After all these technologies are already utilized successfully in commercial real estate buildings, such as care facilities, office buildings, etc. In the media, you mostly see ads for air-conditioning units, when homeowners and real estate investors can actually invest in an inexpensive and often even more aesthetically pleasing cooling alternative, such as those mentioned above. In our opinion, it is only a matter of time as the general public has already started to choose sustainability over convenience.
Since certain technologies can only be beneficial to their full effect, when a system is installed properly, watch for trustworthy contractors with the right references. The consequences of shoddy workmanship when it comes to all HVAC installations can quickly turn into a disaster.