Measuring heating fuel consumption

[Clair]

Our boiler and fuel tank feed two pumps (our house and the gite).

Heating fuel prices having risen so much in the past year, I would like to be able to assess how much the (optional) central heating is actually costing us in the gite. Is it possible to introduce a flow meter in gite feed pipe and if so, can anyone point me in the right direction?

Thanks [:)]

[Gluestick]

Take your pick, Clair!

Basic flowmeters use a revolving paddle: others are more technically advanced.

http://www.google.co.uk/search?hl=en&q=Flowmeter+Heating+oil+Feed&meta=cr%3DcountryUK%7CcountryGB

Edit: It's even better when one spells it correctly.............

http://www.google.co.uk/search?hl=en&cr=countryUK%7CcountryGB&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=Flow+meter+Heating+oil+Feed&spell=1

 

 

[Le Plombier]

You nee a compteur d'energie thermique

This will give you consumption in kW

Best to fit one in each circuit for the two properties and then you can evaluate by simple percentage the oil consumption for each property

Available from a professional plumbing and heating merchant but you will probably need a plumber to install

Le Plombier

[Clair]

[quote user="Le Plombier"]You nee a compteur d'energie thermique

This will give you consumption in kW[/quote]

Thank you both.

Knowing how much I have paid for the fuel, I'd rather have a reading in litres so I can calculate how much heating for one week is actually costing.

Can I ask what you think of this item? http://www1.int.conrad.com/scripts/wgate/zcop_in/~flN0YXRlPTM0MTQ1OTAwMDY=?~template=PCAT_AREA_S_BROWSE&glb_user_js=Y&shop=A_B2C_IN&p_init_ipc=X&~cookies=1

 

[Michael]

Clair.Yes it is easy to install,measure the pipe incoming to your boiler/burner.8mm,10mm or what ever,and buy the appropiate oil meter with compression fittings, do not use Ptfe tape on the oil line when fitting use the correct oil line stag.It would be cheaper to buy the standard meter [not pulsed].Type in -Commercial Heating Control Parts Centre to find out who your nearest supplier is.Michael.

[Gluestick]

Can't open the pagew correctly, Clair. IE reports a Cookie fault.

I deal with Conrad; they supplied my security system; very helpful and quick on parts and spares.

Only trouble is they inundate me with catalogues and mailers!

What you need, Clair, is a direct read out simple flow meter on one feed line only.

KISS

 

 

[Clair]

Sorry about the link. You need to enter the art number top left: 120990 

[Gluestick]

Must be a problem with my system: won't search!

Ridiculous!

I've searched and ordered stuff from Conrad!

I'll try again later after a re-boot.

 

[Clair]

Oil consumption indicator

Article No.: 120990-62

Measure your oil consumption easily and accurately! The method employed is brilliantly simple. In oil heating systems, fuel consumption is directly proportional to the running time of the feed pump. Oil delivery is constant and depends on the burner being used. The consumption rate (in kg/h) is printed on the burner type plate. Normal operating hour counters only show for how long oil has been consumed. However, this counter shows consumption accurately in kg or litres! The measurement is clearly readable on the 8-digit LCD display.
Technical data: Display variants: Operating hours, consumption in kg (accurate to 10 g), consumption in litres (accurate to 10 ml), selected burner rate · Reset button, countersunk to prevent accidental reset · Burner rate adjusted in 50g steps from 1.45 to 3.00 kg/h · 8-digit LCD · Electrical connection via pins on rear · Designed for front panel mounting · Installed dimensions 69 x 33 mm
Control connection 230 V (parallel to feed pump)
Operating voltage 3 V Lithium battery (CR2032) · Current consumption 2.5 µA. Operating time per battery approx. 10 years.

[Gluestick]

One possible problem, Clair.

If the installation is reasonably recent, then the oil feed is feed and return to prevent over-pressure spillage.

Just like a car's feed system for injection.

If your system is feed only, with no return then it should be fine.

One word of caution, however: standard oil-fired boilers (and gas) tend to be delivered as one standard case and core, but with a range of different Brûleur  and jets too for various heat outputs.

On commissioning into service, the Chauffagiste sets up the boiler burner to deliver the optimum fuel combustion: and this is adjusted (or ought to be!) each year when the installation is serviced.

Thus the absolute oil consumption would depend on adjusted and actual oil flow, rather than its designed capacity. Thus some level of error is being introduced here.

I like the engineering concept, however: simply a basic calculator, with user variable parameters and an On-Off pulse from the pump, plus a memory.

The read out will thus be a function of the hours "On" against the expected consumption/hour.

 

[Le Plombier]

Gluestick's comments are valid

If you want an accurate reading you have two options

Fit separate oil tanks for each boiler, this might be the cheapest solution

Fit energy meters, these measure water flow rate in the heating circulation and temperature difference between flow and return

They automatically adjust for any variation in flow and temperature and give accurate power consumption

Most options on fuel metering or burner monitoring will probably give you an inaccurate reading, from minor error to unbelievable consumption

I would never fit any kind of oil metering or burner monitoring for a client as it would be likely they would be complaining and asking for their money back after a few months

Le Plombier

[Gluestick]

A decent flow meter let into one feed line should be reasonably accurate, Le Plomb.

As one example of accuracy, they are used in pubs to deliver specific measures and then cut off the pump.

Petrol and Diesel pump metering is also obviously quite accurate.

Weights and Measures, as we used to call 'em (Trading Standards) are pretty unforgiving over served inaccuracies!

The big thing is finding accuracy (Typically + - 1% say), at reasonable cost.

[Clair]

Thanks Le Plombier, but as regards your suggestion to "Fit separate oil tanks for each boiler, this might be the cheapest solution", we have ONE boiler and TWO independent pumps.

Gluestick, you are right in your thinking the system is "feed and return". The burner is serviced, cleaned and adjusted every year.

I understand the reservations from you both regarding accuracy of readings.

If I had a measure on the tank itself, I would be able to gauge how much is being used more accurately.

The tank is squeezed/pinched in the middle and does not have any apparent markings, except for the tape I stuck on it when we had the last fuel delivery.

Thus I can tell "we've used x cm" and (get Mr Clair to) calculate how much fuel this represent, as long as the level is in the "straight" part of the tank, but I have no idea how much this is once the level reaches the centre part of the tank...

Or am I being blonde [8-)]??? (rethorical question, no reply needed! [:D])

[Gluestick]

Clair:

Impossible to accurately calculate consumption from an irregular shaped vessel.

Mrs Gluey and I have this problem constantly when deciding which of us has drunk most of a bottle of wine!  [:D]

So no: you are not having a Blonde Moment!

Since the system is Feed and Return, metering the feed pipe will not work, as for any fair degree of accuracy, you would also have to meter the return pipe and deduct one from t'other.

I know that Le P's suggestion is used to establish costs and tariffs for fully serviced properties (appartments and condos), however might not work too well in your instance, as they tend to be employed in fairly similar shaped and insulated "Boxes".

Would be worth investigating, however.

For example: http://www.dmsltd.com/Sontex/49

So, depending upon cost, perhaps the cheaper solution is to meter the circulating pumps (use the Conrad device, in this case it's operating as a "Time In Service" device) and calculate the heat input requirement of each dwelling area ( a competent Chaufagiste should be able to do this simply using their standard room demand calculater), and measure absolute fuel consumption by filling the tank, knowing (from the electronics the hours of operation) and then re-filling the tank to the same identical level.

The fuel put into the tank will equal consumption.

In other words if you have 1,000 litres put in and you mark the level and two months later you need another 750 litres to fill the tank to  the same mark, then consumption is 750 litres.

The meters tell you pump operating hours per dwelling and you can thereafter allocate discrete consumption per dwelling unit from the heat input requirements.

By this I mean that if - e.g. - one place is twice as large as the other then divide 750 by three and the cost is the quotient (result) X 1 for the smaller unit and X 2 for the larger.

Hope that's reasonably clear!

The results will be very approximate and not allow for insulation efficiency, heat loss from open doors, hot water consumption and so on.

I myself am off to la belle at sparrows tweat tommorow and won't be around for a week or so.

 

 

[Clair]

[quote user="Gluestick"]I myself am off to la belle at sparrows tweat tommorow and won't be around for a week or so.[/quote]

Thanks Gluestick and have a nice time! The fantastic weather should last another couple of days...[:)]

[bejay]

[quote user="Clair"]

Our boiler and fuel tank feed two pumps (our house and the gite).

[/quote]

Clair

Do you mean by this, two C/H water circulating pumps?

bj

[Clair]

Yes, that's what I mean.

When we bought the property, it had already been divided into two dwellings and only one of those had C/H.

We installed radiators in the other property (now the gite) as a new and independent system.

We can heat both houses at the same time, or ours only, or the other mainly (by shutting down our radiators except for the bathroom one which deliberately does not have a thermostat)

There is a valve above the boiler which favours one pump or the other, depending on its setting.

Apologies for my non-technical description... [:$]

[Le Plombier]

If you only have one boiler and two pumped circuits the only way you can measure the energy consumed by each circuit is with an energy meter in each circuit

They cost approx 350 euros each so it would probably cost you 1000/1200 euros installed

With a single boiler it is impossible to measure how much oil is being consumed for each individual property by fuel oil measurement

Metering oil supply with a two pipe oil system would be a waste of time and may give you a reading in excess of the amount of oil you actually put in the tank

Le Plombier

[Le Plombier]

Gluestick

You cannot just measure hours run on each circulating pump, it is a meaningless exercise as the pumps will be pumping different flow rates and therefore energy consumed will be different for each property

There are too many variables on water, internal and external temperatures plus different flow rates and hours run 

If there are control valves in the separate circuits they will affect the calculation

I doubt you would get even 50% accuracy

The link you post for the energy meter is good, they are good and reliable

Le Plombier

[Clair]

[quote user="Le Plombier"]If you only have one boiler and two pumped circuits the only way you can measure the energy consumed by each circuit is with an energy meter in each circuit.

They cost approx 350 euros each so it would probably cost you 1000/1200 euros installed.

With a single boiler it is impossible to measure how much oil is being consumed for each individual property by fuel oil measurement.

Metering oil supply with a two pipe oil system would be a waste of time and may give you a reading in excess of the amount of oil you actually put in the tank

Le Plombier[/quote]

In that case, we will have to stick the the approximation we guess by calculating the amount used by the family who was here last week.

We measured the drop in the level and given the size of the tank, calculated that the heating had cost around €52.

 As we charged them less than that, I'll know to increase the optional charge in future... [:(], unless the cost of fuel drops of course!!

Thank you very much to all of you for all your suggestions, research and patience [:)].