Central heating radiator energy monitor

Forum about Opentherm, Hvac, House heating, Boilers

Moderator: hvxl

Post Reply
Digit
Global Moderator
Global Moderator
Posts: 3388
Joined: Sat Mar 25, 2006 10:23 am
Location: Netherlands
Contact:

Central heating radiator energy monitor

Post by Digit »

Ever wondered how much heat all the radiators in your house are producing?
All you need is 2 temperature sensors per radiator and some radiator specific numbers which should not be too hard to find or obtain.
With this information it's possible to estimate the amount of energy (in Watt) your radiators are producing.
Central heating energy monitor.png
Central heating energy monitor.png (8.68 KiB) Viewed 6673 times
I'm using this to get a better view on where all the heat, produced by the boiler, goes to.
Sounds interesting? Check http://blog.hekkers.net/2011/12/08/energy-flow-in-watt/ , where the the calculations are explained and what you need to know about your radiators to do this.
phoenixb
Advanced Member
Advanced Member
Posts: 512
Joined: Thu Jul 23, 2009 1:00 pm
Location: Netherlands

Re: Central heating radiator energy monitor

Post by phoenixb »

Nice job you have made.
But i have a little question, when i read you idea over the forumula in combiantion with the EN442 and the characteristic of a heating device i a little bit curious if this is right.
Because how lower or higher the flow temperature is how unreliable the output of the forumla is.

Do you have also a calculating total power on you heating system with this formula:
Q = m.c. ΔT
or with the calculated energy as a result of the combustion heat of gas (and offcourse include efficiency of the boiler)
Grtz,
__________________
Alexander
Global Moderator
Global Moderator
Posts: 1532
Joined: Sat Mar 10, 2007 11:19 pm
Location: Netherlands

Re: Central heating radiator energy monitor

Post by Alexander »

Not using xbee anymore?
Alexander
Digit
Global Moderator
Global Moderator
Posts: 3388
Joined: Sat Mar 25, 2006 10:23 am
Location: Netherlands
Contact:

Re: Central heating radiator energy monitor

Post by Digit »

djdive wrote:Nice job you have made.
Thanks. This last piece of "Watt calculations" was the least time consuming of the whole adventure :)
djdive wrote:But i have a little question, when i read you idea over the forumula in combiantion with the EN442 and the characteristic of a heating device i a little bit curious if this is right.
Because how lower or higher the flow temperature is how unreliable the output of the forumla is.
I've checked a lot of my own calculations with the formulas used by the manufacturers; all were within 1W. Which is not surprising, considering the fact that I use the same formulas. So the only thing I can do to answer your question is to ask the manufacturers whether their formulas are OK. In other words: I can't answer your question. Though I did notice that the Radson formulas have some sort of crossover where the formula changes from the one I posted on my blog to a formula with a more linear result (no power function involved). The crossover depends on the temperatures used; but I still have to look at that in detail. So I think you do have a point here that the temperatures (or better:the differences between them) can make the formula I posted less accurate.
djdive wrote:Do you have also a calculating total power on you heating system with this formula:
Q = m.c. ΔT
or with the calculated energy as a result of the combustion heat of gas (and offcourse include efficiency of the boiler)
Nope...
Some 20 years ago I worked with 2 Honeywell Magnew electromagnetic flow transmitters to measure flow, PT100 sensors inside the piping, a calibrated gas meter with calibration value correction (ijkpunt correctie) and an EVHI to calculate the right caloric value of the gas being used. That setup could produce nice figures about the efficiency of the boiler, but I don't think I'll ever have that equipment here. :wink:
I can't even measure flow right now... :(
Digit
Global Moderator
Global Moderator
Posts: 3388
Joined: Sat Mar 25, 2006 10:23 am
Location: Netherlands
Contact:

Re: Central heating radiator energy monitor

Post by Digit »

Alexander wrote:Not using xbee anymore?
RTFB :wink:
I have bought too much stuff in the past that has never been used, so nowadays when I need to create something new, I first take a look at what I already have before I start buying. This can lead to less obvious solutions :) I had a lot of JeeNodes including RF transceiver, so I decided to use the JeeNodes as temperature sensors. I used 8 Jeenodes in total.

But I did also use 2 XBee modules, for the 2 RF to ZigBee gateways I made: http://blog.hekkers.net/2011/12/02/rf-t ... e-gateway/
For me this was the easiest/quickest way to get RF data on my LAN with what I had in stock.
Bwired
Administrator
Administrator
Posts: 4704
Joined: Sat Mar 25, 2006 1:07 am
Location: Netherlands
Contact:

Re: Central heating radiator energy monitor

Post by Bwired »

Great job
I can use that, i have the same Jaga radiators :D
And also the valvues on it.....
Post Reply

Return to “Hvac, Heating Opentherm Forum”