Thermostatic valves (Attention Novice ...)

[Gauthier]

Hi everybody

First of all great site with a lot of interesting information, this is my first message and I am happy to join the group. I am 19 years old, I am very interested in what is energy saving (in particular in housing), however I do studies of economics / management at the Unif of Namur and I therefore have no technical knowledge, which I greatly regret.

In short, I come to my problem:

I live in an old house. We have five radiators that rotate in places where heat is not really needed.
These are old cast iron radiators that go either full pot or that are either closed (At present most have valves simply blocked, preventing manipulation).
What we thought to do, is to put thermostatic valves in order to save liters of fuel oil ... The walls are thick (25cm, no idea of ​​the composition), we therefore only want to heat the "useful" rooms. and leave the others with just a minimum to avoid humidity.

Budget is an issue, however. The house is very large with only one salary. So I wonder to what extent we will be able to dampen the valves. So I made calculations, as a great novice that I am ...

We consume + - 4500L per year (It is unfortunate, but my mother has neither the budget nor the capacity to invest), we have 13 radiators, that is very hypothetically 346,15L per radiator. We have 5 radiators on which we would like to install a valve, these radiators therefore consume for them at present (5.346,15) 1730,75L.

This is where I need you for what could be saved in terms of liters of fuel oil. Knowing nothing about it, I start from the principle (probably false) that if I put a thermo valve on 1 or 2 rather than letting the cast iron radiator turn fully, I will save 60% of the consumption on this radiator .

Is it very far from reality? How much will I save? You must probably consider the entire circuit, but as I know nothing about it ...

(For those who want to follow my reasoning until the end, I will gain 60% on the 5 radiators, which in the end would decrease the consumption of 692L by taking the 5, which allows to calculate after the return on investment of the valves)

[I Citro]

Welcome Gauthier.
Your reasoning puzzles me, but it lacks neither logic nor scientific spirit.

You must first be sure that your installation is not in series (single-tube network), that is to say that your radiators are well supplied separately by the boiler and that closing a radiator would not close the supply others.

- The thermostatic valve bodies only cost around ten Euro each.
- According to the brands, the thermostatic heads are at an equivalent price.

By searching the net, you will even find for around thirty € programmable thermostatic heads according to the days and hours of presence in the rooms to be regulated.

Normally, the heating engineers recommend installing a thermostatic head on all the radiators except on the one located in the same room as the room thermostat that controls the boiler, and sometimes in the bathroom.

Try to find a good "michel morin" or a service exchange association to learn.
The work that you mention does not require a lot of tools but a certain know-how easy to acquire once well assimilated the installation of the first valve body.
There is not one for 30 minutes by radiator for a pro (15 minutes should even be enough), but easy 1 hour for a beginner.

Saving 30% of energy seems possible, but also check the insulation and airtightness of the windows.

[Gauthier]

Thank you for the answer !

Good first of all I will inquire to know if the food is in series or not .... (It will seem ridiculous to those who know it, but too bad) I fear that it is, because I have always been told to leave the valves slightly open (despite my obstinacy to close them) for the circuit ...
However it seems contradictory to me with the 5 radiators which are on my ground floor and which I have completely closed, with no worries at the level of the other radiators which heat.
So for the moment, I don't know, it's rather ambiguous. If it's serial, I'm fucked up?

My biggest surprise compared to the answer is the "10 euros / piece" for the body and the same for the heads. My grandfather (who is nevertheless a good handyman) told me about ... a little less than 250 euros per valve! Question of radiator? For example, here is the radiator next to me, in cast iron, with its valve (image to tilt):


On the other hand, I have just read a simplified explanatory text on the operation of a thermo valve ( http://www.energie-environnement.ch/con ... mostatique ), according to the case it would seem that it is based on the ambient temperature to cut itself ... I thought that there was a system which "regulated the temperature" of the heating differently, but suddenly seen that it is based on the ambient temperature, I am afraid that it will be so cold that even on 1 the radiator turns fully (It is so cold and the insulation is so zero ...)

(One last thing if someone wants to react; in fact, I am passionate about saving energy, but my studies will lead me to work in management. I wonder what projects I could possibly develop with these management skills in the field of energy ... pq not possibly resume classes, do evening classes or anything, but I don't know where to start. There is a part of the forum where can we talk about that?)

[Gauthier]

I just saw my grandfather, obviously it is a "serial" installation, but with the possibility of closing the radiators individually ...
basically he explained to me that there are two conduits (one going back I guess) running through the house, to which each radiator is connected. I would have to find sites that explain this ...

I deduce that an economy can therefore be done at the level of an individual radiator, even if I am not sure how ...

I know absolutely nothing about it, but from what I've learned in the last few hours starting from 0 this is how I see how it works (It will make the heating engineers laugh ): we have the boiler which heats a liquid (it is simple boiling water which circulates?) which passes in all the house by a pipe thus containing hot water and which comes to supply the radiators, and a second pipe of recovery of the water then + cold which passes by.

The boiler should heat until the room where the thermostat is located is at the desired temperature. If I close a particular radiator, the water will no longer just circulate in the radiator in question, but will have to continue to circulate in the rest of the circuit ...
How do I save liters of fuel oil in there by shutting down a particular radiator? A relationship with the volume of hot water in the network which is smaller and easier to heat? Can someone enlighten me?

Saving 30% of energy seems possible, but also check the insulation and airtightness of the windows.

Could you tell me more about this estimate? Do you speak at the level of the 5 radiators in question, at the level of the entire network?
For the insulation and the air tightness unfortunately difficult to improve the situation significantly without heavy investment, but I will see what I find on the left on the right on this forum which seems to me a small gold mine ...

[Philippe Schutt]

the old circuits were not in series, at least I have never seen one.

10 € for the body is a regular price, it can do a little more for unusual diameters.
But you do not mount a head on top, it would be heated by the pipe. You risk having to take heads with a remote probe.

the economy is done by avoiding unnecessary heating, so if you have a higher T ° in rooms than what you want, it's potential gain. Put it everywhere except where citro said, if you already empty the circuit as much to enjoy it, it's all good.

Your calculation is brutal but not that wrong after all, and the result very plausible or even pessimistic if you heat 5 parts thoroughly for nothing.

[Gauthier]

Thank you for the answer.

the economy is done by avoiding unnecessary heating, so if you have a higher T ° in rooms than what you want, it's potential gain. Put it everywhere except where citro said, if you already empty the circuit as much to enjoy it, it's all good.

I will try to clarify my question on this point.
What I said to myself is that the water is heated and circulates throughout the circuit regardless of whether a specific radiator is open or not; I'm not sure when the economy is.
If the temperature of the thermostat is reached: ok the system stops, we burn less fuel oil, the economy comes from the system shutdown.
More if the thermostat temperature is not reached, an open or closed radiator, I wonder where the savings on liters of fuel oil come from precisely since the boiler must continue to supply the entire system.
If the economy is done "by avoiding unnecessary heating", given the system, the water is heated anyway: it only avoids going into a radiator if I close it. Hence my somewhat technical question on the "how" of the economy, I only have hypotheses in mind.

It would allow me to understand a little better the proportions in which I will be able to save energy on the whole system by limiting the heating of 5 radiators.

My grandfather, who tinkers with me and not at all but who tries to understand, expected a gain of only 5% where I calculated a gain of just over 15%. (692L of savings for me considering a hypothetical savings of 60% of fuel oil consumption on 5 specific radiators - hence my question to understand how I will achieve this savings in fact -, 225L for him considering a savings of 5% on the whole system)

[Philippe Schutt]

If the temperature is exceeded, the tap closes and the boiler no longer receives cold water from this radiator in return and does not need to heat it.
If the temperature is reached or almost the tap is already half closed and the boiler receives less cold water back from this radiator and therefore has less to heat.
If the room is considerably cooler than the requested temperature, the tap is wide open and there is no gain.

Having less water to heat, the boiler will reach its maximum T ° faster and will shut down, even if the living room thermostat does not shut down yet.

[I Citro]

There is indeed little probability that your installation is in series, as far as I can see.

As presented in your link, it is imperative that the axis of rotation of the thermostatic head is horizontal, otherwise it does not work properly.

The choice of valve body must be established according to the type of connection:

For the radiator that you show us, the body that would be suitable would be a inverted square (the model in the top center).
Depending on the nature of your pipes (copper or steel), the assembly can be carried out without welding, with simple adjustable wrenches and what to join (paste, teflon, tow ...).

[dedeleco]

A big problem with standard thermostatic valves is that the simple system for measuring T, which controls opening or closing, is on the valve in direct thermal contact with the circulating water, and therefore with a false T error compared to T of the room, of a large Delta T when the hot water circulates and much lower when it is stopped, which with a measurement of reference T constantly falsified, makes the regulation unsatisfactory, (risk of oscillations ), better than nothing, but not as economical, as if the measurement of T were offset several meters in the room, without ever undergoing the rapid blows of T of the circulating water.
In my opinion a well balanced installation is almost as good and even essential before having these thermostatic valves.

You can balance by closing the balancing valves enough so that the unnecessary parts are much less heated, but still a little, which is also simple, by a few successive tests.

Watch where you lose heat, attic to insulate, cheap and essential, (maybe 30%?), Heating tubes, especially in a crawl space, in a garage or on the ground, to insulate well with thick ducts (gain sometimes 10 to 20%?), and other possibilities to see sometimes simple, thermostat too high in T, with not enough hysteresis, boiler with too hot water? , drafts around the windows to be cut with a few rubber beads, fireplace left wide open which lets out all the hot air in the house (a chimney closing hatch can save a lot of money), burn wood for free collected outside, even in the recycling center, pruning of dried hedges and pruning, sometimes burnt by my neighbors in the open air who keep me so smoky for days, is a great saving, etc.

[elephant]

Indeed, on most of the old Belgian instal, one did not use the serial assembly.

Several points.

4500 liters is indeed huge. In a house with 5 radiators, there is a good chance that you can settle for a third or a half (including an annual gain of € 2250, to invest)

solutions to reduce consumption.

1) for 35 euros, you will find a programmable thermostat if it is not already done: https://www.econologie.com/shop/thermost ... p-172.html . I had one for 6 years, I passed it on to my sister, it is fine. Choose the room carefully where it is placed. No need for VT in this room.
2) adapt the water temperature: 90 ° when it freezes, 60-65 ° in April. Without that, your valves are of little use: the pipes heat the room.
3) insulate the pipes in the cellar if not already done
4) +1 for remote probe heads: they are more efficient.
5) by looking well, you will find between 50 and 75 euros, the most difficult being to find someone who is willing to place them.
6) choose the stop / start times well: I had adjusted the thermostat (which works in one hour increments) to save one hour of heating / day. (start 5:30 am, stop 9:30 am: the inertia of the radiators is good)
7) manage the T ° night: 16 ° is good, going down below is expensive
manage absences if your mom works
9) Your boiler is probably not "the latest model in the living room", so it's a safe bet that the circulator is constantly running. The installation of a timer or an aquastat at 50 euros (thermostat on the hot water outlet) easily saves 400 kWh electric per year.
10) the comfort temperature is not the same throughout the year: if 20-21 ° are necessary in winter, 18-19 ° are often enough in mid season.
11) if the boiler is in the boiler, I noticed that in summer, we made money by completely shutting down the boiler between 10 am and 4 am.

And of course, when possible, it is often profitable to borrow money to insulate: well-sealed double glazing. The attic is often easy to insulate yourself. If it is uninhabited (too bad for the suitcases, they will be cold), it is preferable to isolate the floor from the attic: a crowbar to remove the boards, 16 to 20 cm of glass wool + aluminum, a week end with a friend and voila.

Send me your email address in mp. (not in response on the subject)