Transitioning from Oil to Gas Furnace: Ideal Gas Boiler for 170m2 House with Old Insulation

Question

I'm in the process of changing from oil to gas furnace after 14 years of using an oiler. Home insulated according to the old technology from 14 years ago so max. outside 10 cm, poorly insulated usable attic (but as we have radiators there already a few years have worked maybe a few times - heat...

Zbigniew Rusek · Answer

For heating you certainly do not need more than 16kW, maybe even too much, but what about hot water for the bathroom. Heating water requires more power (the comfort of flow-heated hot water is about 20kW, unless there is a storage tank, but it takes up space). As for the condensing boiler, this temp up to 50 degrees refers to the temperature on the return and not on the supply (condensation depends on the return temperature), and the temperature on the supply is always higher than on the return (50 degrees on the return is usually about 70 degrees on the supply, similarly, 40 degrees on the return will be 60 degrees on the supply, and t. d.). That is, condensation would also occur if the radiators were supplied with 70-degree water (i.e., there would be 50 on the return) and such radiator temperatures are needed only for a few, top a dozen days in winter, i.e., for most of the season the parameters would not exceed 50 degrees supply/30-35 return). Frosts of 15-20 degrees happen occasionally (sometimes there is a heating season when such conditions will not occur at all). A condensing boiler is more economical than a regular one, but more expensive. On the Viessmann website it is stated that even when the installation is designed for 75/60 degree parameters (supply 75 degrees, return 60 degrees, that is, radiators really very hot), even at an outdoor temperature close to minus 10 degrees the efficiency of the boiler will be about 100% at +10 outside will be up to 109%) - there is a chart there.

sartyx · Answer

water tank is 120 l vailant - in my opinion and many others sufficient, when it comes to comfort - it is known - at the moment I do not have hot water, only as I set myself on the stove, so it suits us and probably by this we also save a lot of money,, the question is when these 20KW is really used ? only to heat water ?

Zbigniew Rusek · Answer

Yes, for heating water. After all, a typical bathroom stove - the so-called Junkers has a power of about 20 kW or even a little more (Junkers generally come in versions of 19.2kW or 23.6kW, Vaillant similarly - with the advantage of the smaller power). A 192kW stove provides a flow rate of 11 liters per minute of water heated by 25 degrees (or 5.5 liters per minute heated by 50 degrees); 2306kW provides 14 liters per minute heated by 25 sotpni (7 liters per minute heated by 50 degrees). I emphasize, it is about the increase in the temperature of water relative to the temperature of cold water, not the specific temperature of water. Conclusion - hot water requires about 20kW of power.

sartyx · Answer

then what are 14 and 16 KW boilers for then ????

Zbigniew Rusek · Answer

If there is a storage tank, then you do not need as much power to heat water, as in the case of instantaneous water heating (as in Junkers) and such a boiler will successfully suffice. Only that the storage tank takes up space and has a certain capacity. There are advantages and disadvantages of each method of heating water. Note: a boiler that provides instantaneous hot water heating in addition to central heating is a dual-function boiler (a single-function one can also provide hot water, but when connected to a storage tank).

sartyx · Answer

is it true that if I buy a boiler from an online store I may have a problem with the first startup service for free by the service center ????

piotr_boncza · Answer

No, the first start-up, bought in Poland, is always included in the price of the boiler. More often, you have to pay for the service to get there.

Piotr77777 · Answer

Not all boilers have free of charge first start-up. Secondly, not every authorized service technician wants to fire up boilers bought on the Internet, and thirdly, I have seen boilers bought in Poland on the Internet intended for the market of another country outside the EU, and therefore the warranty was not valid in Poland.

kabee84 · Answer

Immergas Nike/Eolo - first start-up paid 100% by the customer, unless the seller (Installer) in the sales contract offers to cover this cost.Otherwise, often boilers of higher power are also started up for a fee by the user.These are the examples that come to mind. So that you always need to read the terms of the warranty.... Added after 11 [minutes]: Secondly, it is related to the third. If the boiler does not come from an authorized Polish distributor, who would pay for commissioning of the service technician? That's why (very rightly) service technicians do not want to run equipment from an uncertain source (online store). The warranty as a manufacturer's warranty does not apply, but there is such a thing as seller's liability - and we automatically have a 2-year warranty in the case of a consumer sale (the buyer bought it privately, not as a company - the Law on Special Terms of Consumer Sales...). or one year warranty in case of sale to a business entity (Warranty Act). By the way.... I guess it's only in Poland that a customer, based on knowledge taken from the Internet, without any schooling or practice in the field, can choose a heating appliance for himself, build an electrical/hydraulic system, assess the efficiency of chimney systems, build himself a domestic sewage treatment plant - and for all this he will get approval, papers, etc.... And then fires, flooding, failure to meet environmental standards, etc. etc.... Massacre. And further reading on forums, buying on the Internet.... And on and on Maciej.... Poles...

lemonr · Answer

And I guess it is only in Poland that a house project is conquered by many mgr inż among others the one on heating and selects a 24kW gas boiler and in reality 8kW is enough. So graduated school in this area does not prove anything ( in many cases). Thanks to the knowledge of the Internet, it is more difficult for experts to perform magic.

haneb · Answer

Exactly. At my place, the professional who did the whole installation installed 17kW and now after replacing the boiler itself, 10kW is enough.

piotr_boncza · Answer

It's me who apparently has an outdated manual: Preliminary commissioning After completion of all installation work (including filling the system), call Authorized Immergas Service. The service technician will perform the first commissioning free of charge, at the same time instructing the user on the use of the boiler. Note: The first commissioning performed by Authorized Service is a prerequisite for the warranty. The initial inspection ensures maintaining boiler features such as reliability, efficiency and economy. There you are undeniably right, although when I see someone write Polaczki, I get a knife in my pocket.... Added after 45 [minutes]: He selects a boiler with a capacity of 24kW, because that is what is needed to flow sufficient water for washing.The fact that most often less is needed for heating is obvious .

lemonr · Answer

It is not! I am writing about a boiler with a storage tank! And if it were not for the knowledge taken from the Internet, which you so negate I would probably buy one.

mauri_b · Answer

From last year, there are other provisions in the warranty card, saying that there is a charge for the first commissioning of a non-condensing boiler. Condensing boilers still have free commissioning with reimbursement of travel costs. Similarly in Vaillant, except that there is no obligation for the first commissioning by the service of traditional boilers, while in Immergaz there is an obligation - to have a warranty.

kabee84 · Answer

Exactly. As for MA and projects.... Let's not hide - the designs of heating systems in the general designs of single-family houses are on a copy-paste basis, universal, matching most houses. And so - a house of 110m2 and 240m2 have the same boiler rooms.... Decent installation companies are there to customize the heating system for a given building taking into account all the guidelines (also how many people will use the house, what the temperatures should be, etc., etc.) For the rest - a 24kW boiler (even if it is not a 2-function version but with a hot water exchanger) for a 170m2 house is not some glaring mistake.

lemonr · Answer

Well, let me add that this is a design for an energy-efficient house (186m2 of which 150 heated area), is it still not a glaring error?

lemonr · Answer

I have been to two such specialists both on the letter V. And what, they did a cost estimate based on the provided design with a 24kW boiler. Which industry specialist has the time to spend more than 30 minutes with a client?

lukaszon · Answer

And what do you think about such a boiler with a capacity of 25 Kw ? The price of such a boiler from the manufacturer is about 5300 PLN + free transport Will be enough for 150 m2 ? .

Arbiter · Answer

25kw is probably for a 700m2 house (contemporarily insulated)

Transitioning from Oil to Gas Furnace: Ideal Gas Boiler for 170m2 House with Old Insulation

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