Tips Central heating wood pellets following buy house

[julius87]

Hello,

I am new to this forum, I find the site very interesting and enriching, I learned a lot, but I need advice on my case ... thank you for reading me

Here, I bought a house at the end of December equipped with central heating by wood pellet boiler. The former owner explained to me the operation, the maintenance and gave me the instructions, everything works. But given the different topics, I think there are things to improve. You tell me ...

Here is the detail :
House Year 1983 of 120m2 on 2 floors: concrete block + glass wool + plastered brick.
Central heating was installed less than 5 years ago in place of electric convectors. There is also a fireplace with insert.



The boiler is installed in a shelter about 20 meters from the house:



Pellets are stored in the open room next to the boiler:



The boiler is an HS Tarm MultiHeat 2.5



The water temperature is set to 80 °

There is a circulator at the outlet of the boiler. The circuit goes under the courtyard, the pipes are well insulated according to the former owner (I trust)



It happens in my cellar, where there are 2 other circulators and the hot water tank that goes electric in summer. Then the adjustment is made by an adjustable valve from 0 to 10 which is very sensitive, the slightest angular degree changed greatly varies the degrees celsius in the house.
I am on 2 and it is on average 23 ° in the house.



Then, there are 4 radiator circuits in the house equipped with simple taps:



Well, sorry for the poor quality of the photos.

* The previous owner spent around 3 Tons of pellets until the end of December, is that a lot? I brought in 3 more, that will make 6 Tons in all.
* Is it useful to put thermostatic valves on my radiators (all?)
* Should the water temperature leaving the boiler be lowered? 80 ° is the T ° noted on the boiler manual ...
* Can I close several radiators without worries?
* Is it possible to put a thermostat which controls this valve or another?
* Should we close the silo completely, can it improve performance? Maybe the pellets get wet? I plan to do it in the spring anyway.

Thank you in advance

[Christophe]

Hi and welcome!

A) The first intriguing thing is the positioning of the boiler in a room "apart" very far from the house: the calories must arrive in the house with the minimum of losses of course!

However I see that at the level of the boiler no pipe is insulated. Is the roof of the room? I very much hope that the pipes that go to the house are and not just a little. Are they buried?

B) Did you ask why the boiler room was so far from the house?

C) In terms of consumption, you can make the equivalent: 2 kg of pellets = 1 L of fuel oil.

So 6 T is 3000L of fuel oil so it's quite a lot but must be brought back to the region and m² to be heated.

D) You surely received a DPE during the purchase? What's he saying?

In short: start by checking the insulation of the pipes.

[julius87]

Hello Christopher,

Thank you for your quick reply.
The boiler is distant for noise and this room already existed, so they did that. The pipes are buried at 1m with good insulation. But it is true that in the room, there is no insulation ... it is well heated by the boiler! but it's true that this is not the goal ...
The house is in Isère and is 120m2 habitable and heated
The DPE announces class D with 259 Kw / m2 / year if I remember correctly.

[Christophe]

Well if it is good in a not isolated room that is not supposed to be heated: it is not good ... it means big losses (boiler, pipe ...)

Ok so start with

a) insulate your pipes in the room (0.5 to 0.9 € / m depending on the pipe diameters). Absolute priority.

b) check the loss of temperature between the room and the arrival in the house. For this you can use a thermometer like this: https://www.econologie.com/shop/thermome ... p-326.html



c) insulate the roof (see the walls) of the room with at least 4 cm of insulation.

What is a boiler brand? Installation year?

[Did67]

1) Same opinion: given the surface area of ​​the accommodation, consumption is important.

2) But a priori, it is not the heating installation that should be called into question first, but the level of insulation. The DPE estimates the "need" of the house (sparks surfaces, level of sparoies insulation, taking into account climatic demand).

If the demand is approximately 250 kWH / m² / year, whatever the heating, boiler, output, regulation, etc ... you will need to "pump" 250 kwh x 120 m² / year in your house = 30 000 kWh / year = 6 tons of pellets per year = 3 l of fuel / year

Except of course to tackle the holes in the space, that is to say insulate.

So the question should not start with the boiler!

3) That said, we can isolate the pipes, it's a minimum.

4) Then, the priority improvement, for me, would be to automate the regulation: motorize your valve if possible (or replace it with a motorized V3V) + outdoor sensor

With this you program your comfort and lowering ranges and above all, your regulation permanently adapts the temperature in your heating circuit according to the needs (which result from the outside temp: + it gets cold, the more you have to send the hot water at high temp to compensate).

5) Once this regulatioon in space and the heating curve ("water law") well adjusted, you can see what is the maximum temperature you need.

You can then lower your boiler temperature a little because the more you ask for a high temperature, the higher your losses will be and the lower your performance will be.

[Did67]

I cannot see with enough precision the jumble of pipes behind the boiler ...

A priori, you seem to have a protection system against too cold returns, by recirculation of hot water, with a thermostatic valve. It's good. This protects the boiler against condensation.

In this case, the regulation I am talking about cannot pose any technical problem for the boiler.

It will be an optimization (count a gain of 5% per degree gained internally; it will not "revolutionize" your system, but it is always won).

[manet42]

I allow myself two or three suggestions:
-See the possibilities of insulating the house.
-The thermos taps. with your manual valve, they can be useful for adjusting the T ° of the parts finely. Leave a normal one.
-If you decide for an outdoor probe and a motorized valve with water law, they become troublesome (one or two in specific places, acceptable).
-It is essential to insulate the pipes.
-A little insulation in the boiler room, no need to heat the street.
-The pellet store open to all winds, not good for humidity:
A wooden floor, a door and possibly a false ceiling or filling the voids of the corrugated iron would be the minimum.
Good work.

Jc

[Christophe]

I obviously agree with the insulation but if 30% of the power does not arrive IN the isolated part ...

You see what I mean?

Personally, even if it's a big job, I would move the boiler room to put it in the house ...

I think that the losses of this assembly are from 1 to 2 Ton of pellets / year.

It would be worth thinking about.

To find out, measure the boiler outlet / house inlet T °.

[dedeleco]

Totally agree with the previous remarks very questionable insulation !!
In Isère, what altitude?
Cute house, installation which at first glance looks good !!!

but for a 1983 house, all electric, it seems to consume a lot, 259KWh / m2 / year, seems very big to me, I would wait 150 to 200 rather seen that with a house 10 years before, non-electric, earlier we do not exceed 200 !!!
What thickness of insulation in walls and roof spaces?
You risk exceeding 6 tonnes per year ???
Given the serious lack of insulation on the very long pipes in the photos, we must reconsider everything and measure the thickness of the actual buried pipes, it must exceed 10cm without defect, otherwise you lose a lot of heat and then I think you gain nothing compared to the all-electric old, with pellets at 300 € per ton. !!!!

In addition, to know the best operating mode, you must measure the actual consumption of pellets !! Crucial to know the real and not theoretical gains which can be archival !!!
and compare to the electric one.

With gas it is easy, we look at the meter, and we see that the continuous operation of modern boilers is not necessarily the best with large external losses like you !!

Better intermittent powerful very short and very long rest for minimize these very large losses, what modern boilers no longer do and almost impossible on continuous operation pellets !!!!

So by insulating the pipes, then walls and roof spaces, all with the maximum, more than 10cm, you have a potential of gain in enormous consumption (more than 2). To my taste with the pipes alone 30% gain !!! (and 7 to 15% by the most intermittent operation possible without improved insulation).

[Did67]

Manet is right:

1) no need to have two types of regulation (thermostatic valves AND motorized valve / probe): a) it can be annoying; b) above all, it is a double expense, one of which is useless

2) the hotter your boiler room, the lower the boiler losses will be; however, put the insulation at house level first! I suppose your boiler is already insulated (glass wool under the body?). Otherwise, in a pinch, what I would do is surround your boiler with plates of "high temperature" glass wool + insulate the pipes ...

3) Fortunately your HS boiler is quite rustic. A high performance boiler would risk calling on your pellets exposed to all winds. As far as I know, it maintains the fire and does not work automatic ignitions.

You're right, humidity decreases the yield (you have to evaporate the water). The advantage of pellets is that they are a standardized fuel delivered very dry: better performance, less polluting emissions ... So letting them regain humidity, it's a shame (the absorption of humidity, c 'is like crisps or dry cakes: once opened, the contents of the box "rammolite" from the invisible humidity in the air; this stabilizes around plus or minus 12%).

If this lasts, the pellets may even fall apart a bit.

The ideal remains an airtight silo (and it will still be recommended to empty every two years).