Gentlemen, I am in such a dilemma. I have a boiler with a tubular heat exchanger https://sermeta.com/en-gb/product/mhytech/ In this exchanger, 8 turns are in contact with the burner (output part), 4 turns are behind the burner - WG return, condensing part. Which temperature pair will provide better efficiency and better condensation?
Exit 50 / return 30 Exit 40 / return 35
At such low temperatures, condensation occurs on the entire surface of the exchanger, but more so in the part behind the partition.
Maybe I`ll describe it like this. I live abroad and I`ve seen a lot, but I don`t know anything about it, so I`m certainly not surprised that it looks like the work of a crazy service technician. It`s probably true, but how to deal with it now. Ground floor apartment, neighbors overhead. A large living room and kitchen and 2 rooms in which the doors are open only at night and locked. There are 3 radiators in the living room + one small one in the open corridor, in 1st floor rooms. The rc310 controller menu looks like this: I changed both parameters to 45 and on the stove, to be sure, after pressing the radiator icon, also to 45. I don`t understand why one parameter is defined as the maximum heating temperature and the other as the maximum temperature for the radiators, because for me, a layman, they are the same thing. The weather at night was 6 degrees, from 3 p.m. to 7 a.m. approximately 7 m3 was consumed. As I wrote, the radiators are turned all the way up, because I treat the whole thing as one room. I forgot to write that my goal is to maintain a constant temperature for 24 hours. During the day 20.5-21 at night 19.5-20 month old baby at home and someone stays all day.
This suggests that the installation contains elements that are not resistant to higher temperatures, so I suspected that in addition to radiators, you also have underfloor heating. This is a common combination, because the floor itself causes stagnation of air circulation in the apartment, and radiators do not allow this, forcing air circulation in the apartment. If you live on the ground floor, there is a high probability that due to poor insulation in the ceiling, you heat your neighbors upstairs. It`s the opposite for me, I live upstairs and my wife and I don`t like temperatures above 18 degrees Celsius, and our neighbors downstairs, Brazilians, like the warmth and not only warm us up, but overheat us so much that we sweat at night like in a sauna. If it`s your own apartment, you should consider the possibility of installing good insulation between floors, because heat always goes up, so the ceiling is always a few degrees warmer than the floor, and if the ceiling is weak or there is no insulation, most of the heat is he goes to the neighbors upstairs.
Added after 12 [minutes]:
pawlik118 wrote:
Gentlemen, I am in such a dilemma. I have a boiler with a tubular heat exchanger https://sermeta.com/en-gb/product/mhytech/ In this exchanger, 8 turns are in contact with the burner (output part), 4 turns are behind the burner - WG return, condensing part. Which temperature pair will provide better efficiency and better condensation?
Exit 50 / return 30 Exit 40 / return 35
At such low temperatures, condensation occurs on the entire surface of the exchanger, but more so in the part behind the partition.
I believe that the first one is more beneficial because it also lowers the flue gas-condensation temperature and increases the heating temperature, which means that the boiler will operate for a shorter period of time and with more favorable energy consumption parameters. Some boiler users often choose the latter option, as more heat energy escapes with higher temperature exhaust gases, and the boiler operates in such conditions longer to provide more energy at a lower circulation temperature.. This energy released in exhaust gases is often ignored. Even by condensation specialists.
At 40-35, the flow through the furnace is, let`s say, 550 liters per hour, which gives 3.3 kW If you want to maintain the power of 3.3 kW for a temperature of 50-30, 130 liters per hour, i.e. the flow is 4 times smaller, depending on the installation, there may be problems with orificating the installation at such low flows.
At 40-35, the flow through the furnace is, let`s say, 550 liters per hour, which gives 3.3 kW If you want to maintain the power of 3.3 kW at a temperature of 50-30 130 liters per hour, i.e. the flow is 4 times smaller, depending on the installation, problems may arise with orifice of the installation at such low flows.
Boiler efficiency is not only regulated by flow, but also by burner power. I guess I don`t need to explain the difference. In general, if you increase the burner power with the 50/30 parameters I mentioned, it will not in any way affect the energy loss at the exhaust gas outlet. This increased power will go to the radiators, not outside.
Of course, the stove modulates the power of the burner, but it is the water that transfers this energy to the central heating installation, which then transfers it to the heated rooms. It is worth installing a heat meter in the central heating system and familiarizing yourself with the principle of operation. https://www.wikiwand.com/pl/Licznik_ciep%C5%82a
If you install such a heat meter on the exhaust gases, you can calculate the boiler efficiency. Burner power = Central heating installation power + Exhaust gas power (losses)
Efficiency = Burner power/Central heating installation power
Of course, the stove modulates the power of the burner, but it is the water that transfers this energy to the central heating installation, which then transfers it to the heated rooms. It is worth installing a heat meter in the central heating system and familiarizing yourself with the principle of operation. https://www.wikiwand.com/pl/Licznik_ciep%C5%82a
If you install such a heat meter on the exhaust gases, you can calculate the boiler efficiency. Burner power = Central heating installation power + Exhaust gas power (losses)
Efficiency = Burner power/Central heating installation power
You can install thousands of gadgets, but they do not affect the efficiency of the boiler, only the user`s well-being and the balance on the account. It is enough to check the settings during the annual inspection and correct them if anything has changed. I don`t understand what you wanted to say with the second part of the sentence; "but it is the water that transfers this energy to the central heating installation, which then transfers it to the heated rooms." This fragment seems to suggest that the economics of heating depend in some way on water. For me it`s an incomprehensible mystery.
That is, the burner power, e.g. 5kW = water flow that transfers energy to the central heating installation, e.g.: 4kW + 1 kW escapes through the chimney.
saskia wrote:
Boiler efficiency is not only regulated by flow, but also by burner power
I don`t understand this sentence either, and it is contrary to what I wrote above and the principle of conservation of energy.
That is, burner power, e.g. 5kW = water flow that transfers energy to the central heating installation, e.g.: 4kW + 1 kW escapes through the chimney.
saskia wrote:
Boiler efficiency is not only regulated by flow, but also by burner power
I don`t understand this sentence either, and it is contrary to what I wrote above and the principle of conservation of energy.
Boiler efficiency is the amount of energy obtained for heating. This includes practically everything that helps to collect fuel energy from the boiler and deliver it to the radiators. That is, temperature range and flow, primarily. And the flow is water in central heating, so I don`t understand what you meant when you wrote what I quoted earlier.
And if you are writing about specific boiler power, you should note that the higher you set the return temperature, the higher the exhaust gas temperature will be, i.e. more energy will escape into the chimney. If you add a supply temperature slightly higher than the return temperature, the boiler will not only have to work longer to provide the appropriate amount of energy to the central heating, but it will also do so with a greater loss of exhaust gas energy.
so comparatively and approximately, at a temperature of 50/30 the boiler will work for e.g. 4 hours, using 4 KW of these 5 from fuel, and 1 KW will go up the chimney. However, at 40/35, the boiler will have to work an hour longer to provide these 4 KW, and not 1 KW but 1.2 kW will go into the chimney for 5 hours, not 4 hours. Ultimately, in the first version of the setup, you will have 4 KW of the 5 used, with a loss of 1 KW for the chimney, and in the second version of the setup, you will have 4 KW gained, but 1.6 kW will go into the chimney. so the actual consumption will not be 5KW, but 5.6KW. These are not exact calculations, just showing the proportions in the use of fuel energy at different settings. The fact that the flow needs to be increased at higher powers is the norm in order to properly set up the boiler, and any problems with throttling the flows in the installation itself are a problem of the installation itself and its professional implementation, not a problem of setting up the boiler. If someone messed up the installation, it needs to be corrected and not messed with uneconomical boiler settings. This is why the installation design and calculations are made so that there are no problems with the boiler working and the installation not working. Many savings on pipe cross-sections result in higher costs of energy losses, already in one year of operation, so by saving PLN 1,000 on pipes, we will pay an additional PLN 1,000 for heating each year, which will go up the chimney every year. Personally, I made gravity heating on copper, and although the gas boiler heats it, I have no problems with flows or any other issues. I can use 5 different heat sources; gas boiler, fireplace, power generator as its cooling, and its electric energy. and solar panels.
The discussion revolves around the optimal condensation temperature for a condensing boiler, specifically focusing on the return temperature necessary for effective condensation. Participants agree that the return temperature should ideally be below 57°C to facilitate condensation, with some suggesting that lower temperatures enhance efficiency. The optimal flow and return temperatures discussed range from 40-55°C for various heating systems, including those with underfloor heating and radiators. The importance of proper radiator sizing and system configuration is emphasized to achieve efficient operation and minimize energy consumption. Users share their experiences with different boiler models and settings, highlighting the need for adjustments based on external temperatures and building insulation. Summary generated by the language model.
