Background
Summary of Council decision:
Four issues were investigated of which one was Upheld and three were Not upheld.
Ad description
A Fact Sheet sent to enquirers in March 2010 promoted a boiler optimisation control system. Page 2 was headed "Subject M2G integration with Building Management Systems [BMS]". Body copy stated "Most BMS systems control the various heating / cooling zones etc … During these control functions, the burners/boilers are turned on or off irrespective of whether the burners are fully modulating, high/low or at the correct operating temperature for the best thermal efficiency of the boiler plant. In some cases the BMS may sequence the boilers according to load requirements, this is normally done via a common system flow or return temperature determining a set point and P.I action to 'cascade' the boilers as and when required. The disadvantage of this type of sequencing is, unless you isolate the boiler hydraulics that are not currently firing, this will cause system hysteresis and temperature dilution of the required flow temperature set point".
Under the heading "How the M2G integrates with BMS" further text stated "The M2G has been specifically designed to overcome and avoid unnecessary 'dry cycling' of the boiler operation under low load conditions, such as for 'standing losses' etc.".
Page 3 was headed "Subject: The difference between Building Management Systems and M2G". Text stated "The boilers are normally connected to a heating system via common flow and return heaters; in this case the BMS will have temperature sensors installed to measure the combined [underlined] common flow or return from all of the boilers ... The BMS does not measure the direct flow and return temperatures of each individual boiler. The M2G has two digital temperature sensors to measure and calculate the direct temperature profile of each boiler, thereby establishing if the boiler thermostat is making a false 'call for heat' ... The BMS does not: [underlined in bold] Measure direct boiler flow/return temperature measurement on each boiler ... The BMS can control the boilers and burners in the following ways, some of which are detrimental to the boiler plant: The control circuit / stat of the boiler may be interrupted via the BMS relays; this will turn off the boiler/burner irrespective of burner firing position or direct set point. Modulating burners can be turned off at high fire, causing thermal shock to the boiler. It is not untypical for the BMS to isolate the mains electrical supply to the boiler to turn off the boiler. This can cause safety issues with the combustion safeguard control functions ... M2G is specifically designed to directly optimise and control boiler load and is designed to complement BMS and boiler controls".
Page 4 was headed "Fact Sheet". Under the heading "How does it work?" text stated "By measuring the boiler system demand / load via two digital temperature sensors on the flow and return pipe work and by the adaptive algorithms the M2G will measure and calculate the boiler load profile .... This will ensure the boiler does not fire unnecessarily for light load conditions or conditions of standing losses from the boiler. Thus saving energy and maximising boiler efficiency".
Issue
MilTec System Design challenged whether:
1. the claim "Most BMS systems control the various heating / cooling zones etc … During these control functions, the burners/boilers are turned on or off irrespective of whether the burners are fully modulating, high/low or at the correct operating temperature for the best thermal efficiency of the boiler" was misleading, because they believed that a correctly applied BMS directly controlled high or low fire stages and fully modulated each boiler accordingly;
2. the ad was misleading, because it implied that by not having flow and return sensors on each boiler in a system, BMS's were less efficient than a BMS and M2G combined;
3. the claim "The BMS can control the boilers and burners in the following ways, some of which are detrimental to the boiler plant" was misleading, because they did not believe the three examples given were detrimental to the boiler plant; and
4. the claim "M2G is specifically designed to directly optimise and control boiler load and is designed to complement BMS and boiler controls" was misleading, because they believed the M2G system would conflict with BMS.
Response
Sabien Technology Ltd (Sabien) said the document referred to as the "ad" was in fact two separate Fact Sheets that had been combined for the benefit of a prospective client who had already had the M2G device and its application explained to them. They did not believe the two Fact Sheets, which they believed covered different subjects, should be considered together as they were not intended to be read simultaneously.
1. Sabien said the BMS did not typically control the firing stages of the burner or directly control the modulation rate. They said that was normally carried out by the boiler's load control or the boiler's own integral boiler thermostats and controls. It was possible that a BMS system could control the firing rate of the boiler, but that was the exception, not the rule. They said they had specifically used terminology such as "most", "in the above cases" and other general terms so that they did not imply that all BMS systems were controlled in that way.
2. Sabien said they had not implied or stated in any of their published information that the M2G was a more efficient alternative to a BMS and they explained that 95% of their clients had BMS systems in place. They said M2G was designed to be integrated with BMS systems and to deliver functionality on top of what the BMS already achieved.
They said most BMS systems measured the flow and/or return temperatures of all the boilers connected to a common header and therefore measure the combined/blended temperature of all the boilers. It was therefore technically and physically impossible for the BMS to identify which of the boilers connected was "dry cycling". The only way to identify "dry cycling" was to measure the flow and return temperatures of each boiler. The M2G device measured the flow and return temperature of each boiler and therefore identified when a boiler was "dry cycling" thus preventing the boiler from firing unnecessarily and resulting in reduced energy consumption and improved boiler efficiency. They said it was technically possible, with the appropriate additional hardware and programme strategy, for a BMS to replicate the function of the M2G but that in practice that would be more expensive than installing an M2G, and any programme strategy could not contravene the M2G patent. In their experience, they had never come across a BMS set up in that way, which was why the M2G had been able to achieve savings when installed in addition to a BMS at their client's sites. The provided a number of client statements to that effect.
3. Sabien referred to literature from several sources in support of their claim that the three examples given were detrimental to the boiler plant. They also provided an expert report on the M2G by David Strong Consulting, a report by The Chartered Institution of Building Services Engineers (CIBSE) titled "The development of a dynamic model to simulate boiler controls" and letters from Autoflame Engineering Ltd (combustion management solutions), Hamworthy Heating Ltd and Hoval Ltd (boiler manufacturers), Heating Process Engineering Services Ltd (heating engineers) and HMP Wealstun, which they believed demonstrated that the three examples provided were common occurrences that were detrimental to boiler plant.
In relation to the first example "The control circuit / stat of the boiler may be interrupted via the BMS relays; this will turn off the boiler/burner, irrespective of the burner firing position or direct boiler set point", Sabien said that typically the BMS was managing the boilers from a common header temperature, it was not controlling the individual boilers/burners. As a consequence the BMS would not know if the boiler was at its designed set point, or at the manufacturer's recommended DeltaT [temperature differential between the water that enters the system to be heated and the temperature of the water once it has been through the system] and therefore any interruption to the boiler/burner by the BMS could lead to frequent cycling of boilers over time and could compromise the designed criteria of the boiler and lead to potential damage. They said those limitations and potential detrimental impacts to the boilers were widely recognised in the industry, as demonstrated by the expert letters they had provided.
In relation to the second example, "Modulating burners can be turned off at high fire, causing thermal shock to the boiler", Sabien said most conventional three-pass boilers operated at a designed chamber resistance as determined by the boiler manufacturer's published data. Larger boilers with high turn-down ratio burners would have low flame hold capabilities and, through the burners' PID/load control, would always ensure the burner started at low fire and modulated back to the designed point (possibly at low fire). They said that interrupting the burner at high fire would cause a pressure pulse in the boiler which could cause thermal stress and that this was supported by the expert letters they had provided.
In relation to the third example, "It is not untypical for the BMS to isolate the mains electrical supply to the boiler to turn it off. This can cause safety issues with the combustion safeguard control functions", Sabien said enabling/disabling the boilers by isolating the electrical supply to the boiler/burners from the BMS could cause direct safety issues in relation to European Standards EN 298. Those controls required a constant electrical supply to enable the control to check for after-burn fault conditions and avoid disabling the required flame supervision sometimes known as the "dark check". They provided six examples of installations where they had encountered the BMS isolating the mains electrical supply to the boiler to turn it off, which represented a small cross section of findings in the field.
4. Sabien said the M2G was designed to complement existing BMS and boiler controls. Over 95% of the M2G installations had existing BMS and boiler controls operating, and in all cases the M2G did not and continued not to conflict with the existing BMS/boiler controls. They explained that the M2G took direct instructions from the BMS and delayed the boiler from firing as instructed by the BMS until the temperature difference between the flow and return sensors indicated that the firing was necessary (or until it reached its maximum pre-set time delay). Because it did not draw on any other input, it could not interfere with the operational parameters that were set by the BMS or other boiler controls. They provided data that compared the pattern of boiler firing when the M2G was and was not applied to a BMS system with "Optimum Start Control" (OSC), which they believed demonstrated that the M2G did not interfere with other boiler controls.
They said the M2G had been installed in the estates of a number of large commercial companies and within critically sensitive sites. They said the M2G integrated with, and complemented, the existing BMS and they provided a number of testimonials from clients to that effect.
Assessment
The ASA noted that the Fact Sheets had been combined into one document to be sent to a prospective client, and that was the document we had received a complaint about. We considered that, whether one document or two, the pages headed "M2G integration with Building Management Systems [BMS]" and "The difference between Building Management Systems and M2G" dealt with interrelated subjects. We considered that the interpretation of the challenged claims was not altered whether the Fact Sheets were regarded as one document or two documents, sent to the same prospective client at the same time.
1. Not upheld
We took expert advice. Although we understood that it was possible for a BMS to control the firing rate of a boiler, we understood that in most cases the BMS did not directly control the firing rate and instead simply enabled or disabled the boiler. It was then left to the boilers' own controls to govern the boiler firing rate. We noted the wording of the ad stated "Most BMS systems control the various heating / cooling zones", and "The boilers are normally connected to a heating system via common flow and return heaters". Because in most cases the BMS did not directly control the firing rate of the boiler, and because the ad made that clear, we concluded the claim was not misleading.
On this point we investigated the ad under CAP Code (Edition 11) clauses 3.1 (Substantiation), 7.1 (Truthfulness) and 19.1 (Other comparisons) but did not find it in breach.
2. Not upheld
We noted Sabien's assertion that the ad did not imply their device was more efficient than a BMS, but highlighted its ability to identify which of the boilers connected was "dry cycling" by measuring the flow and return temperature and therefore prevent the boiler from firing unnecessarily, which delivered savings over and above those achieved by a BMS alone.
We noted that page 3 of the Fact Sheet was headed "The difference between Building Management Systems and the M2G" and that text stated "the BMS does not measure the direct flow and return temperatures of each individual boiler. The M2G has two digital temperature sensors … thereby establishing if the boiler thermostat is making a false 'call for heat'…". In addition, page 4 stated "By measuring the boiler system demand / load via two digital temperature sensors on the flow and return pipe work …. the M2G will … inhibit boiler firing … Thus saving energy and maximising boiler efficiency at all times". We therefore considered readers of the Fact Sheet would understand that the reason the M2G could maximise boiler efficiency was through its flow and return sensors.
We understood that a BMS system was capable of carrying out the same function as the M2G if flow and return sensors were fitted and the BMS was programmed accordingly. However, we understood that it would be extremely unlikely for a BMS to be set up and programmed in that way and that Sabien had never come across such an installation.
The ad stated "the BMS does not measure the direct flow and return temperatures of each individual boiler" and we therefore considered it implied a BMS alone would not save energy and maximise boiler efficiency in the same way as the M2G, which relied on those sensors to measure the flow and return temperature, "saving energy and maximising boiler efficiency ...". Because in practice BMS systems were not equipped with flow and return sensors and/or programmed in a manner that allowed them to identify boiler dry cycling, we concluded the implied claim that the Sabien device could provide added efficiency (when incorporated into a system with a BMS already in place) because it had those sensors had been substantiated and was not misleading.
On this point, we investigated the ad under CAP Code (Edition 11) clauses 3.1 (Substantiation), 7.1 (Truthfulness) and 19.1 (Other comparisons), but did not find it in breach.
3. Upheld
In relation to the first example, we considered that the references in the literature provided demonstrated that every time a boiler started and stopped, the fluctuation in temperature would induce some stress in the boiler casing. Furthermore, we accepted that more frequent boiler firings would increase the stress induced. However, we considered that the stress could only be said to be detrimental to the boiler casing if it exceeded the level that the manufacturer had designed it to withstand and we understood that a competently configured BMS could avoid too frequent firings by properly matching the boilers to the available heating load.
In relation to the second example, we understood that the higher the firing rate, the higher the temperature of the boiler casing and the greater the stress. However, the references in the literature provided by Sabien showed that when the boiler was switched off at high fire, the result was a decrease in thermal stress as the boiler casing cooled. We considered that the evidence did not support Sabien's argument that a damaging pressure pulse was formed when switching the boiler off at high fire.
In relation to the third example, we considered that the control strategy referred to would only be damaging for certain types of boiler. We noted that of the six examples Sabien provided of non-domestic installations where they had encountered this boiler control method in use, three had no post-shutdown safety devices or checks and would not therefore have been damaged if the mains power supply had been switched off. A further two examples included insufficient detail to determine the type of boiler arrangement and it was therefore not possible to assess the implications of switching off the power supply. We considered that the final example, which did require a power supply to be maintained post-shutdown, was not a competent or legal installation if indeed the power supply had been cut off by the BMS and we considered that by definition such installations must be in the minority.
We considered that readers would understand that, when the control strategies referred to were applied, they would cause damage to the boiler plant. We accepted that turning off the boiler too frequently would cause stress to the boiler plant, as would isolating the mains supply to certain types of boilers to turn them off, and we noted that several industry professionals had witnessed installations that used those control strategies. However, we understood that a BMS that caused a boiler to turn off too frequently would be considered poorly installed and that a BMS that isolated the mains supply to a boiler for which that would be detrimental would constitute a non-competent installation. Furthermore, we did not accept that a damaging pressure pulse was formed when switching the boiler off at high fire.
Although conditional language was used, the ad gave no indication that the examples given would result from poor or non-competent installations, which gave the impression that properly installed BMS systems would cause damage to the boiler plant over and above the unavoidable thermal stress caused over time in all boilers. We considered that the ad gave the impression that those issues would not arise if an M2G was installed and that it encouraged readers to purchase an M2G to avoid the risk of their BMS damaging their boiler plant. Because we understood that a properly installed BMS would not damage the boiler plant as the ad suggested it would, we concluded that the ad was misleading.
On this point, the ad breached CAP Code (Edition 11) clauses 3.1 (Substantiation), 7.1 (Truthfulness) and 19.1 (Other comparisons).
4. Not upheld
We understood that the control strategy feature for boilers called optimum start control (OSC) was not necessarily offered by all BMSs and therefore might not be universally available as an option, and that even when present it was up to the discretion of the programmer whether or not they utilised it.
However, we understood that when available and enabled by the programmer, the OSC function used sensors that measured room and outside air temperature to decide on the optimum start and stop time for the heating system. The OSC was then programmed with the desired occupancy times of the building, starting the boilers before the occupants were due to arrive so that the building was warmed up. The same process also applied to the boiler switch-off time at the end of the day.
We understood that the presence of another device in the boiler start sequence, which might prevent a boiler from firing when commanded by the BMS, could cause the building to warm up more slowly than the OSC had calculated which could result in the OSC bringing the boilers on earlier the following day to compensate.
We noted the ad claimed that the M2G was fully compatible and complementary to all types of BMS systems, and we considered that should include systems that had an OSC strategy. While we understood that the function of the M2G was to delay boiler firings when it deemed them unnecessary, we accepted that the evidence we had seen demonstrated that the M2G would not delay boiler firings in a manner that prevented the BMS from warming the building in the time calculated by the OSC. Because the evidence we had seen indicated that the M2G was compatible with systems, including those that used features such as OSC, we considered that the implied claim that the M2G was always compatible with all BMS systems had been substantiated and was not misleading.
On this point, we investigated the ad under CAP Code (Edition 11) clauses 3.1 (Substantiation), 7.1 (Truthfulness), but did not find it in breach.
Action
The ad must not appear again in its current form. We told Sabien to ensure that they did not imply that a properly configured BMS would damage boiler plant in future.
