WO2016189206A1

WO2016189206A1 - Method for improving energy efficiency of heating systems in buildings

Info

Publication number: WO2016189206A1
Application number: PCT/FI2016/050367
Authority: WO
Inventors: Jukka AHO; Lassi VIITALA; Seppo Laine
Original assignee: Leanheat Oy
Priority date: 2015-05-28
Filing date: 2016-05-26
Publication date: 2016-12-01
Also published as: FI20155404L

Abstract

The invention relates to a method for improving energy efficiency of heating systems in buildings, in which method at least one measuring sensor is installed in all apartments of a building to collect data that will be used a basis for adjustment measures of the heating system. In the method, measurement data obtained from the measuring sensors is analysed by means of a suitable algorithm and, on the basis of the measurement data, apartments best suited for adjustments are searched for. On the basis of the analysis and the search, apartments best suited for adjustment in terms of overall cost-efficiency are selected.

Description

METHOD FOR IMPROVING ENERGY EFFICIENCY OF HEATING

SYSTEMS IN BUILDINGS

The invention relates to a method for improving energy efficiency of heating systems in buildings, in which method at least one measuring sensor is installed in all apartments of a building to collect data serving as a basis for adjustment measures of the heating system.

According to studies, as much as 75 % of apartment buildings in Finland suffer from poor initial adjustment of heating. An imbalance in the heat- ing system leads to large temperature differences between different apartments. Some apartments are uncomfortably hot while others are uncomfortably cold. Typically, the imbalance between temperatures of different apartments may well be as much as 4 to 5 degrees. Imbalances exceeding six degrees are not rare either.

In addition to the comfort of living, an imbalanced heating system also significantly impairs the energy efficiency of a building. Heating in centrally heated apartment buildings must be adjusted according to the coldest apartment, while some of the other apartments are overheated unnecessarily. Each overheating degree increases energy consumption by about 5 to 8%.

The problem is widely recognized in the field and different solutions to solve it have been developed over the years. Often a disadvantage of the prior art solutions, however, is their high cost, due to which repairs are postponed or left undone altogether. Moreover, prior art solutions do not even nearly always improve on the situation, but the problem may become still worse despite expensive repair works. Prior art solutions are also often one-off measures, yet the achieved balance is expected to stay for 5 to 10 years, although in reality this is not the case. We therefore find ourselves in a situation where over three quarters of apartment buildings in Finland are overheated because of some cold premises.

If the imbalance in heating systems could be dealt with in a cost efficient manner, energy consumption in Finland's entire stock of apartment buildings and terraced houses could be reduced by as much as 20 %. This corresponds to an annual output of one nuclear reactor of the Loviisa power plant.

There are a number of prior art solutions for balancing temperature differences between apartments. The most common solution is balancing and basic adjustment of the heating system once every 5 to 10 years. This aims at bringing the heating system in shape at one go for the next 5 to 10 years. Often the goal is to achieve a temperature of 21 +/- 1 degrees in the apartments.

A better, yet in practice a significantly more rarely used solution is to balance building temperatures by using what are known as measurement kits. Most measurement kits contain wireless temperature gauges that may be temporarily placed in apartments. The temperature data thus collected may be utilized for balancing heating.

In general, all prior art solutions are one-off measures that do not allow the gained advantages to be verified and monitored over a longer period of time. Hence they lead to a situation where the owners of the real estates are unaware of the temperature balance in their properties.

In the following, prior art solutions are described in greater detail. For a basic adjustment and balancing of a heating system, a one-off HVAC condition survey is carried out first to check the condition and age of the equipment and to measure the temperature of the apartments. The planner then computes default values for the different components in the HVAC system on the basis of a theory. Finally, the contractor adjusts the default values of the different parts of the heating system to correspond to the theory. In most cas- es, a single final control measurement of the temperatures in the apartments is made and a protocol of the measurements is drawn up.

However, the prior art solution described above involves several practical problems. Firstly, the one-off measurement of room temperatures carried out during the initial survey does not tell the whole truth about the temper- ature balances between the apartments but only reflects a current situation. In reality the temperatures in the premises should be monitored over several weeks, preferably months, to enable a reliable comparison to be made between the average temperatures. External factors may cause momentary deviations of several degrees in long-term averages of temperatures in the apart- ments. A momentary measurement or one carried out for a few days may thus produce a misleading picture of the situation.

Another problem in the traditional balancing described above is the thinking that valve setting values calculated on the basis of a theory will lead to indoor temperatures conforming to the theory. Although set values based on a theory are a good starting point for valve positions, there are a number of uncertainties between the theory and the praxis, and they often cause a mislead- ing end result. Calculation based on a theory unavoidably relies on rough estimates about thermal insulation, functioning of ventilation, etc. in the different parts of the building. In practice, the real situation never corresponds to theory. For this reason, temperatures in some apartments may well remain much low- er than planned if the insulation of the windows and balcony doors, for example, in the apartment is not in the condition assumed by the theory. Alternatively, if ventilation in the building is not at a balance conforming to the theory, the need for heating based on the theory will not be met in the apartments and hence the indoor temperature will not correspond to the plan.

Moreover, even if target temperature values were momentarily reached, in practice the situation in the building changes constantly, and the temperature balance may deteriorate even rapidly. Traditional balancing does not, however, include continuous monitoring of conditions, which is why the real situation is no longer known after the protocol has been drawn up.

The traditional balancing described above is often expensive, its results are difficult to verify and the stability of the advantages is not monitored. Nevertheless, it is indispensable if the heating system in the building has reached the end of its life cycle and the equipment has to be replaced in any case due to failure.

If the heating system equipment is not yet at the end of its service life to a very large extent, a more cost-efficient solution may be to replace single faulty devices and adjust the other. In those cases it may be more cost efficient to balance the heating by using measurement kits. Most measurement kits contain wireless temperature gauges that may be temporarily placed in the apartments. The sensors are left in the apartments for two weeks, for example, after which the gathered measurement data are used for taking corrective action in selected apartments. The sensors and the measuring system are then collected and taken to a next site.

However, balancing done with the measurement kits is not a prob- lem-free solution. It is poorly applicable to systematic maintaining of a temperature balance in large real estate stocks, because taking the measurement kits to and from the sites alone causes significant costs. In addition, the collected measurement data are often analysed manually by means of spreadsheet programs, which further increases the need for resources.

Further still, measurement kits are subject to some of the same problems as traditional balancing. Although the period of time measured with them is often longer, for instance a few weeks, it is still too short to provide a reliable picture of the temperature balance at the site. A yet greater problem arises when the sensors are retrieved, because data on the real situation are then lost, similarly as in traditional balancing. Hence balancing made with measurement kits is similarly a one-off measure after which the achieved balance is assumed to remain unchanged.

When measurement kits are used for balancing, it is also necessary to somehow select the sites to be balanced. Since continuous temperature measurements at the sites is not provided, there is no advance knowledge of where the worst problems lie. Consequently, the sites have to be selected on the basis of intuition, not facts. Since balancing of the entire real estate stock in this manner is considerably expensive, this is not a sensible option.

It is an object of the invention to provide a method that allows the drawbacks of the prior art to be eliminated. This has been achieved by the method of the invention. The method according to the invention is characterised in that measurement data is continuously collected from measurement sensors and the measurement data obtained is analysed by means of a suitable algorithm, apartments best suited for the adjustment being then searched for on the basis of the measurement data and, on the basis of the analysis and the search, the apartments best suited for adjustment from the point of view of overall cost-efficiency are selected.

An advantage of the invention is, above all, that it allows significantly more uniform living conditions to be obtained than prior art technology. In addition, the invention enables considerable energy savings to be achieved because the average temperature in a building can be kept lower for its entire service life without the residents having to suffer from cold.

In the following, the invention is described in greater detail with reference to the accompanying drawing, in which

Figure 1 is a schematic view of the advantages of the method ac- cording to the invention over traditional methods, and

Figure 2 is a schematic view of different steps of the method according to the invention.

The invention approaches the problem from a new angle. The prior art solutions are based on periodic inspections and repairs. The method of the invention is based on a continuous measurement and light, iterative repairs. The invention is thus a method in which temperature divergence between apartments in apartment buildings and terraced houses with central water- heating systems may be identified, corrected and the corrected state maintained with the help of continuous monitoring with significantly less resources and lower costs than before.

Figure 1 illustrates the advantages of the method according to the invention based on fine adjustment over traditional methods. A widely held belief is that once a building is completed there is a good temperature balance between the apartments and that the balance also stays good for a long time. Typically, traditional balancing of heating systems is carried out every 10 years, for example, as an attempt to remedy a temperature imbalance by using known methods.

Because the results of traditional prior art methods are poorly verified, another widely held belief (shown with a broken line in Figure 1 ) is that once repairs have been made, the temperature balance is again almost the same as originally and remains unchanged for another 10 years. In reality, the situation may be much worse. Traditional prior art methods may well provide clear improvement, but reliable verification of the degree of the change is difficult. In addition, temperature balance is not a constant variable and starts to deteriorate rapidly if the site is left on its own after a one-off repair measure.

Due to the above facts, the results of traditional prior art methods may well resemble the curve drawn with an unbroken line in Figure 1 . At regular intervals, a one-off repair measure brining about a momentary improvement is carried out, but the conditions start to deteriorate quickly and, in the long term, the site drifts towards an even worse state.

In the solution according to the invention, an automated and continuous temperature measurement is carried out in the apartments during the entire life cycle of the building. Automatic alarms and analyses enable quick reaction to a deteriorating temperature balance, thus allowing the heating system to be continuously kept in a good balance with simple measures. As a result, significantly steadier living conditions are achieved and, above all, savings in energy because the average temperature in the building may be kept lower for the entire life cycle thereof without the residents having to suffer from cold. In Figure 1 , a double line shows an end result achieved by means of the method according to the invention.

Figure 2 is a schematic view of the different steps in the method according to the invention. For the fine adjustment process, each apartment must be provided with at least one temperature sensor. The sensors are installed in step 1 shown in Figure 2. The sensor may be wireless or wired and besides temperature it may also measure other variables, such as humidity or pressure. The sensors produce measurement data on the conditions in the apartments to a database every 5 to 15 minutes. Also other sampling intervals may be applied, if needed.

In the method according to the invention, the measurement data accumulating in the database is continuously analysed by the algorithms employed, which search a large mass for sites best suited for the fine adjustment process. This step is depicted in Figure 2 as step 2. In principle, the sites are ones where temperature differences between the apartments are the greatest. However, all sites in this category are not necessarily suitable for a fine adjustment process. Sites where few individual cold and hot apartments cause most of the imbalance are best suited for the fine adjustment process. The algorithms used in the invention identify these sites from among the other ones. Sites where the imbalance is great but uniformly distributed among the apartments are not the most preferred ones for fine adjustment and therefore traditional heating system balancing is recommended for these. In sites of this type, there are often more serious problems in the heating system, and therefore a thorough condition survey and, when necessary, replacement of equipment is needed.

After the site has been selected, the system analyses which apartments are the ones that benefit from adjustment. This step is shown in Figure 2 as step 3. Most often, these apartments are in the average the coldest and the hottest ones in the site in question over a specific period of time. The period may be from weeks to several months. For the most reliable results, a period of several months is recommended. In addition to cold and hot apartments, the system also selects those from which temperature measurement data have not for some reason been available or they have been of an unreliable nature. Measurement data have not necessarily accumulated if the temperature sensor in the apartment has been damaged, for example. On the other hand, if the reading of the temperature sensor has been intentionally manipulated, it is not reliable. The system identifies such apartments and recommends checking of the sensor location and its functioning in connection with a visit to the site.

When the system has selected the apartments in which repairs may be carried out with the best overall cost efficiency, it automatically produces instructions for fine adjustment. This step is shown in Figure 2 as step 4. The fine adjustment instructions include a list of all the apartments to be inspected and the recommended measures for each apartment. On the basis of the instructions, it is easy for the serviceman to visit the site to check the selected apartments and make the repairs. This step is shown in Figure 2 as step 5. During the visit, the serviceman checks the selected apartments and the condition of their heating system and performs the recommended adjustments. The adjustment measures include e.g. inspecting the functioning of the different parts of hot-water radiators and changing the initial adjustment values to correspond to those recommended for the system. In addition, the inspection includes taking into account other factors influencing the heating needs of the apartment. Examples of these may be checking the tightness of windows and balcony doors and checking the functioning of ventilation.

After the serviceman's visit, the monitoring of the temperature balance at the site is continued as normally in accordance with the method of the invention. If the results aimed at are not achieved during the first visit, the system recommends a new visit to the rest of the apartments with deficiencies.

The method according to the invention for fine adjustment of a heating system differs from the prior art solutions due to the continuous monitoring and the iterative approach. Since a visit to a site is inexpensive, the final balance aimed at does not need to be achieved at the first time but several visits may be paid. Consequently, the balancing of the heating system may be performed as a continuous process during the entire life cycle of the building. Real-time measurement of the actual temperature balance enables the current situation in the entire real estate stock to be always known and maintained by proactive methods.

The invention has been described above with reference to the example shown in the figures. However, the invention is in no way restricted to the example of the figures but may be freely modified within the scope of the claims.

Claims

1. A method for automatically identifying from a large stock buildings with a temperature imbalance suitable for fine adjustment, in which method at least one measuring sensor is installed in all apartments of the building, data collected by the sensors being used as a basis for adjustment measures of the heating system, wherein

- measurement data from the measuring sensors are continuously collected into a database and the measurement data in the database are ana- lysed by means of a suitable algorithm and, on the basis of the measurement data in the database, apartments best suited for adjustments are searched for, and

- on the basis of the search for and analysis of the measurement data in the database, apartments best suited for adjustment in terms of overall cost-efficiency are selected, characterised in that the selection of the apartments best suited for the adjustment is made after the analysis of measurement data and search for apartments best suited for the adjustment over a predetermined period of time and in that apartments with the coldest and hottest average temperatures over the period of time are selected as the most suitable ones for adjustment measures.

2. A method as claimed in claim 1, characterised in that apartment-specific fine adjustment instructions are automatically drawn up for the apartments best suited for adjustment.

3. A method as claimed in claim 2, characterised in that inspec- tions, adjustments and repairs in accordance with the fine adjustment instructions are carried out in the apartments.

4. A method as claimed in any one of preceding claims 1 to 3, characterised in that the steps mentioned above are repeated according to need.

5. A method as claimed in claim 1, characterised in that the predetermined period of time is a period covering anything from weeks to several months.

6. A method as claimed in claim 1, characterised in that apartments selected as the ones that are best suited for the adjustments also in- elude those for which no measurement data has been available or the measurement data has been of an unreliable nature.

7. A method as claimed in any one of preceding claims 1 to 6, characterised in that the measuring sensors measure the temperatures of the apartments.

8. A method as claimed in claim 7, characterised in that the measuring sensors also measure other variables besides temperature, such as humidity and/or pressure.

9. An arrangement for automatically identifying from a large stock buildings with a suitable temperature imbalance for fine adjustment, the arrangement comprising at least one measuring sensor to be installed in every apartment of a building and arranged to collect data arranged to be used as a basis for adjustment measures of the heating system, the measuring sensors being configured to continuously collect data into a database, and the arrangement further comprising means arranged to analyse the measurement data in the database by applying a suitable algorithm, to search for apartments best suited for the adjustment on the basis of the measurement data in the database, and to select on the basis of the measurement data in the database the apartments that are the most suitable ones for the adjustment in terms of overall cost-efficiency, characterised in that the means are arranged to select the apartments best suited for the adjustment over a pre-determined peri- od of time after the measurement data entered into the database has been analysed and the apartments best suited for the adjustment have been found, and in that the means are arranged to select apartments that have the coldest and the hottest average temperatures over the period of time as apartments best suited for the adjustments.

10. An arrangement as claimed in claim 9, characterised in that the means are arranged to automatically draw up apartment-specific adjustment instructions for the apartments best suited for the adjustment.

11. An arrangement as claimed in claim 9 or 10, characterised in that the means are arranged to repeat the above described measures ac- cording to need.

12. An arrangement as claimed in claim 9, characterised in that the predetermined period of time is arranged to be a period covering anything from weeks to several months.

13. An arrangement as claimed in claim 9, characterised in that the means are arranged to also select apartments for which no measurement data has been available or the measurement data has been of an unreliable nature as apartments best suited for the adjustments.

14. An arrangement as claimed in any one of preceding claims 9 to 13, characterised in that the measuring sensors are arranged to measure temperatures in the apartments.

15. An arrangement as claimed in claim 14, characterised in that the measuring sensors are arranged to also measure other variables besides temperature, such as humidity and/or pressure.