Choosing Furnace & Heat Buffer Size for 114m2 House, Solar Panels & Underfloor Heating

Hello, I have a question, can anyone help me in choosing the size of the furnace and the heat buffer? we are building a house with an area 114 m2 of usable space + garage about 32 m2, 4 people, simple, compact body. We want a solid fuel stove - coal / wood, underfloor heating on the ground floor and the attic, possibly a heater in the bathroom and maybe in the corridor near the stairs. To reduce the frequency of servicing the furnace, we want to install a heat buffer, maybe 1000l?. In addition, we would like solar panels to heat the water in the summer period, or to support heating in the winter period. I want fairly quick and professional advice, we will be laying the plumbing soon and we want to buy the entire installation this year.
I have seen a lot of connection diagrams and I do not know what to use when:
in summer he wants to heat domestic hot water
in winter, he wants to heat the apartment first and then load the buffer - how to distinguish it?
I understand that the solar panels are included in the coils at the bottom of the buffer - how does the utility water heat up?


I will be obliged to help in this topic - recommendation of producers, etc.
Monika

What boiler? Feeder, manual operation? ...

Manual operation without a feeder - so-called "garbage" stove, i.e. wood and possibly coal.

Added after 3 [minutes]:

and what kind of church this is what I'm trying to find out. The store has an 18kw valuation and a 800 liter tank. The problem is that the seller was not able to talk about the buffer and it seems to me that he refused what was on his hand, and not what results from his experience and knowledge.
I tried to tease the topic and it seems to me that a 1000-liter tank and a 20-20kw stove will be appropriate.

If it is a modern construction, the boiler will be much too big due to its power. But due to the fact that it has a larger charging chamber, its operation will be less frequent.
Instead of a buffer, the price of which, along with accessories, will cost a lot, I propose a pellet burner. Virtually maintenance-free with a minimum amount of ash.

But the cost of buying a pellet stove and the pellet itself is not a small cost.

To the author: you have a good idea. It all depends on how much time you can spend on service. If a lot and costs are important to you, even the stove can be without a feeder because the buffer will take the surplus and provide heat when the stove expires. A gasification furnace would be ideal, but it costs a bit - although some are used at a good price (I used to get one myself to remake the system at home).

Make DHW on flat collectors with a tank with an additional coil to be able to connect the boiler to it (through valves to close in the summer).
The bigger the buffer the better. It is only worth oversizing the radiators a bit to be able to benefit from a lower temperature in the buffer. Maybe consider a floorstand.

I just want to install a floor on 2 levels and 2 radiators (garage + entrance, as there is no wind).
The boiler is a bit bigger to fill it up better - I do not have the feeder option, because I do not have space for it.

Does anyone have such a layout and will help with a practically used scheme or a specific advice.

I have to buy this year to be able to deduct VAT for new construction.

How long is the buffer to keep heating?

If you can have gas, there is nothing cheaper in such a small house. You can invest in a cheap installation, buy a freestanding wood stove and have peace of mind.

vatoloco wrote:

or specific advice.

Let's suppose:
- thanks to the floor heating you will be able to discharge the buffer loaded to 90 degrees to 30 degrees
- the peak demand of your house is 5kW

Your buffer will be enough for a 14-hour heating break in January. During the transition periods, it will be at least a day.

However, it is worth considering whether it would not be a better solution to make a thick, accumulative spout.

Unfortunately, we cannot pull the gas up.
As for the buffer, the estimated time of maintaining heat in winter periods would be about 12 hours. It is important for us that the furnace heats up the budor relatively quickly (we looked through the offers of buffers and it is difficult to get something over 1000 lirt).
The question is what power should be heated with such a buffer.
Should the buffer have 1 or 2 coils (we are thinking about solar panels)
How and what is controlled so that after lighting the furnace, it initially warms the floor and then the heat is transferred to the buffer.

spinkamidi wrote:

... we looked through the offers of buffers and it is difficult to find something over 1000 liras ...

Page 24 -> http://www.galmet.com.pl/uploads/files/katalog_wyrob%C3%B3w_01.2013.pdf

William Bonawentura wrote:

Let's suppose:
- thanks to the floor heating, you will be able to discharge the buffer loaded to 90 degrees to 30 degrees
- the peak demand of your house is 5kW

Your buffer will be enough for a 14-hour heating break in January. During the transition periods, it will be at least a day.

However, it is worth considering whether it would not be a better solution to make a thick, accumulative spout.

Hello

Do you know what the boiler temperature must be to load 1000 liters to 90 degrees?

greetings

At least 90 ...

the size of the furnace with the buffer is of less importance. It is the buffer that takes over the regulation.
Bake the bigger the better because it has a large loading chamber. So a single charge will allow you to transfer more energy - less time to work with the boiler.

The temperature on the floor should be given by an automat (three-way valve). The water in the buffer will very rarely (unless you leave) drop below 30 degrees. And a sufficiently large boiler will quickly heat the water to 30 degrees, which is already the temperature suitable for heating the floor.

You can make an additional circuit for such situations to temporarily close the buffer. But I don't know if it's worth complicating the system.

What about DHW heating - how should it be solved?
I mean the cooperation between the buffer and the DHW tank

Hello

I will write you briefly what it looks like with me. I smoke with wood. I pump from the boiler to the buffer with one pump, the second pump pumps from the DHW buffer depending on the needs and the set temperature on the controller, the third pump works in the exchanger - 3D valve system, and the fourth largest pumps to the radiators and floor heating. When I burn in the boiler, three pumps work, the fourth one from the DHW is rarely turned on.
The advantages of such a solution, a buffer as an additional protection of the boiler in the absence of voltage, I burn in the boiler all the time and all heat goes to the buffer and is stored, I do not throw dirty smoke into the atmosphere .
Minus: long heating up of the buffer with the daily firing up, or something wrong .
It seems to me that the system consumes a lot of electricity.

in case you had any questions, I'll be glad to help

greetings

spinkamidi wrote:

As for the buffer, the estimated time of maintaining heat in winter periods would be about 12 hours

With such requirements, it probably makes no sense to pack in a buffer, because by loading the furnace with coal (in my case, kwkd15), in severe frosts, I have peace of mind for a minimum of 12 hours. The surface is similar, but the house is old, pre-war and uninsulated. At the current temperature, full charge is sufficient for 24 hours

Raising the temperature of 1000 liters of water by 60 degrees (assumption: we heat from 30 to 90)
it is about 251 Mj of energy, equal to about 70kwh

Let us assume that the calorific value of coal is 25MJ / kg, so 10 kg of coal is needed to charge such a buffer.

In fact, more is needed because I do not take into account the losses and efficiency of the boiler


let's assume that for heating you need a continuous power of 4kw, such a buffer will be enough for 17.5 hours.

In my opinion, if you play with the buffer, let it have at least 3000 liters, then it will be enough for over two days, then you can buy, for example, a wood gasifying stove.

With a small buffer capacity, it is not profitable to pack it because the costs and complexity of the system increase significantly and the energy in it is as much as in a full coal carbonator

And there is nothing to be delighted with modernity, because the current boiler rooms, installers can stuff them with various pumps, valves, blowers, controllers, etc., with later only this problem is because the user does not know what it is for, there are more elements to break down and the pumps consume energy - the pump 40W, if he works still about PLN 15 per month, not much, but when there are 3 such pumps and the electricity bill is every 2 months, we already have almost PLN 100 on the bill more

wowka wrote:

In my opinion, if you play with the buffer, let it have at least 3000 liters, then it will be enough for over two days, then you can buy, for example, a wood gasifying stove.

With a small buffer capacity, it is not profitable to pack it because the costs and complexity of the system increase significantly and the energy in it is as much as in a full coal carbonator

Basically right. In systems where the boiler does not have a tray, you do not need to regulate the boiler, but burn it with the greatest efficiency, i.e. almost to the maximum. Then even a small buffer will spread it over time and it will be more comfortable.
But the fact is, the larger the buffer, the more comfortable it is.
Somewhere I read about the idea of a buffer in the form of a concrete vat. It was an open system. Lined with polystyrene and foil.

aye, sorry to anyone who might have gone offended- I had a bad day yesterday.
It's better today.
Please take a look at the diagram and assess whether it is possible with such a connection:
a) heating from the furnace only and exclusively DHW (without heating the buffer) - and whether it makes sense
b) recovering energy from solar energy and placing it in a buffer.
I thought about using a solar kit with a 300l exchanger with 2 coils and a buffer without a coil.

When it comes to the buffer, is it worth going in enamel or will ordinary steel be sufficient?

Once again sorry for the previous post

Added after 1 [minutes]:

Maybe write more precisely what you mean. Do you want to heat hot utility water with solar panels, and why a buffer? or if the hot water heater could not accept any more heat? In winter, there is little use of solar panels, there is no question of heating CO at all.

Write the way you want it to work, then we will propose a diagram

Besides, I don't know why you insisted on this buffer with such a small and new apartment. Do you want to smoke in the oven twice a week from morning to evening to have peace for the rest of the days?

The idea is to smoke as little as possible - during the day we will not be at home for 10 hours and after returning, we want the first step to be lighting up the stove.
The buffer is to be used to burn the furnace as little and as short as possible with the full power of the furnace with a power of ~ 25KW.
Solar panels are to be an additional option to DHW during the summer so as not to smoke in the stove.
He writes about the heat exchange from DHW to the buffer tank when during a hot day (e.g. in our absence) the entire DHW tank has been filled.
Answering your question - this is how I want to burn as little as possible in the stove, which is why there is underfloor heating throughout the house so that in a sense it plays an accumulative role.

If it is still valid, in order to have clean hands and not to play with smoking and to push costs, instead of a buffer, put a pellet burner in the boiler of your choice ...

Do you sell these pellets that you insisted so much? Clean hands and no work is gas. Personally, if I had to operate boiler houses, I prefer peas instead of pellets, which costs the same and is much more caloric.

Unfortunately, I do not have the option of placing a furnace with a feeder (too narrow boiler room), hence the decision about a buffer that will be placed outside the boiler room.

Well, nothing in particular, so I feel it. Kostrzewa Ceramik 25KW furnace. The in progress buffer. Most likely, the choice will be a handmade 1500l stainless steel + coil (it will be about PLN 2500).

spinkamidi wrote:

Well, nothing in particular, so I feel it. Kostrzewa Ceramik 25KW furnace. The in progress buffer. Most likely, the choice will be a handmade 1500l stainless steel + coil (it will be about PLN 2500).

You feel good.
In the design assumptions, the following are used: 40-80 l. Buffer for each kW of the source's power.

1.40 lx 25 kW = 1000 l buffer min.
2.80 lx 25 kW = 2000 l buffer max.

in my humble opinion, the bigger the better. :!:

Don't forget to mix in the return water, this is a solid fuel boiler and the best
combustion parameters are obtained at a fairly high temperature in the boiler (80-85 ° C).

greetings

spinkamidi wrote:

Well, nothing in particular, so I feel it. Kostrzewa Ceramik 25KW furnace. The in progress buffer. Most likely, the choice will be a handmade 1500l stainless steel + coil (it will be about PLN 2500).

Everything that could be said about the buffer: http://forum.muratordom.pl/showthread.php?742...to-quot-si%C4%99-robi-czyli-bufor-ciep%C5%82a

No need to make stainless steel tank, this is boiler water, not utility water with lots of oxygen, ordinary steel tank will outlive you and maybe even your children

spinkamidi wrote:

Well, nothing in particular, so I feel it.

Really ? and in post No. 17 what do you have? Start to think a little yourself, and if you don't want to pay someone else for thinking.

Unless you want this specific:

You need a buffer of 6000 liters. It will also be good And that roads are not my business anymore


With such a size, a good dolniak is enough, which you will cover up to the full once every 16-24 hours

I have:
furnace 25 KW Kostrzewa Ceramik
1500l stainless steel buffer - coil lights, etc. to be made
solar panels (in the near future) with a 300l tank? with double coil
flooring everywhere - 10 sections, about 1400-1500 m of pipe.

I care about such functionality that:
The 1st 25KW furnace heats the buffer and hot water
2 solar panels heated by hot water and return excess energy to the buffer (in case of hot days and low water use)

I will be grateful for a hint on how to combine these elements to get the given functionality (whether to make a buffer with 1 or 2 coils)

spinkamidi wrote:

I care about such functionality that:
The 1st 25KW furnace heats the buffer and hot water
2 solar panels heated by hot water and return excess energy to the buffer (in case of hot days and low water use)

I will be grateful for a hint on how to combine these elements to get the given functionality (whether to make a buffer with 1 or 2 coils)

I have more or less this arrangement in the boiler room.
1. The DHW tank must have two coils (one for solar and the other for boiler water). Unfortunately, typical bivalent tanks are on average suitable for such an installation because the upper coil heats only half of the tank, so the stove will heat only half of the tank and it will not be enough for the household members (it was not enough when burning in the stove once a day). Solar panels heat the entire tank, which is OK. You have to use some water mixing system in this tank for the stove to heat up all the water.
2. The accumulation tank must have one solar coil or a plate heat exchanger with an additional pump.
3. In order for the accumulation tank to be loaded from the top and to have a high temperature of water returning to the stove, you need to use a Laddomat, or something instead.
4. As a controller distributing heat from the buffer, I recommend Euroster UNI2, which I am very happy with and I have radiators and underfloor heating.

And here I scribbled what it could look like


By the way.
This winter I bought a wood gasifying furnace about which I wrote on my website www.geospot.pl, please http://www.geospot.pl/atrykuly/inne-pomysly/1...eju-opalowego-piec-zgazowujacy-drewno-golzgas