Are all circulation pumps electronic

Filikin

In a central heating system, the circulation pump pushes the hot water around the system to heat the radiators. My understanding is that an electronic circulation pump can vary its speed depending on how much heating is required and that these pumps are five times more efficent than the old fashioned ones that were just on or off. My question is - are electronic pumps now standard with new installations or do I have to specifically specify one? I am getting a new oil fired condensing boiler and the quote just says "six metre pump".

sullzz

i have never come across one in a domestic situation yet , i have come across them in commercial jobs used on heating , air con , and dhw , id say they are very expensive , im not sure if you could even get one small enough for a domestic situation but i could be wrong

gorwanvfr

Filikin wrote: »

In a central heating system, the circulation pump pushes the hot water around the system to heat the radiators. My understanding is that an electronic circulation pump can vary its speed depending on how much heating is required and that these pumps are five times more efficent than the old fashioned ones that were just on or off. My question is - are electronic pumps now standard with new installations or do I have to specifically specify one? I am getting a new oil fired condensing boiler and the quote just says "six metre pump".

Most of the new pumps are variable, it is not an automatic control but a switch on the pump itself so you can set the speed of the pump.

sullzz

sorry this is the type of pump i thought he was talking about
http://www.grundfos.com/web/grfosweb.nsf/Webopslag/UGRD-4FVQPD

gorwanvfr

sullzz wrote: »

sorry this is the type of pump i thought he was talking about
http://www.grundfos.com/web/grfosweb.nsf/Webopslag/UGRD-4FVQPD

WOW now thats a pump and a half.:D

sullzz

gorwanvfr wrote: »

WOW now thats a pump and a half.:D

sure is , its the only electronic heating circulating pump i can think of , i dont think you would call a standard circulating pump electronic

gorwanvfr

sullzz wrote: »

sure is , its the only electronic heating circulating pump i can think of , i dont think you would call a standard circulating pump electronic

Agreed

Filikin

no, I was thinking of a energy-efficient central heating pump that works by matching its speed to the actual requirements of your radiators. Grundfos do models that are A rated and claim to be able to drop the power to 5 watts based on requirements.
They say they use "variable speed pressure control", whatever that means.

JohnnieK

The pump you are looking for is a Grundfos Alpha2 pump. It is the little domestic brother of the Magna. It is a smart pump. It works best with zoned heating and TRV's. It senses the pressure rise from closing valves and adjusts it's speed accordingly. It would be more expensive than a standard pump but shouldn't be anymore than 200.

Merch

Are these available from plumbers suppliers only? any ideas what rating a normal electric pump (DHW) pump is?

Filikin

JohnnieK wrote: »

The pump you are looking for is a Grundfos Alpha2 pump. It is the little domestic brother of the Magna. It is a smart pump. It works best with zoned heating and TRV's. It senses the pressure rise from closing valves and adjusts it's speed accordingly. It would be more expensive than a standard pump but shouldn't be anymore than 200.

that's the one I was thinking of, but my installer says that I can't use it because my system is open (there is a top-up tank in the attic). He doesn't want to convert it to a sealed system because some of the pipes are steel and are embedded into the concrete floor. I think he is concerned that the extra pressure from a sealed system will burst the pipes he can't get to. Does this make sense?

sullzz

would you believe i was in heatmerchants earlier today and saw a brochure for the grundfos alpha 2 , the first time i saw one of these , very impressive

heinbloed

Filkin wrote:

He doesn't want to convert it to a sealed system because some of the pipes are steel and are embedded into the concrete floor. I think he is concerned that the extra pressure from a sealed system will burst the pipes he can't get to. Does this make sense?

That the pipes are bedded in concrete wouldn't matter. Except that they would be badly insulated.
But the pressure resistance should always be tested dry, with air, to avoid a spillage. If the system holds the pressure : no problem to pressurise the system.
It's a routine plumber's job.

B.t.w.:
All major manufacturers of circulation pumps have electronic regulated circulation pumps available, not only Grundfoss. Wilo has a good range as well, they might be a bit cheaper.
These pumps can of course be installed in open (vented) systems.

Merch

Curious, what would the advantages of being able to increase/decrease the pressure/flow in my system? other than reducing power consumption would it increase/alter its efficiency in heat transfer?

Filikin

one of the guys here found that slowing down the pump caused the rads to take longer to heat up and longer to cool down. Makes no sense to me since the pump is switched off during the cooling down period.
Running the pump slower is more energy efficient

heinbloed

Merch asks:

Curious, what would the advantages of being able to increase/decrease the pressure/flow in my system? other than reducing power consumption would it increase/alter its efficiency in heat transfer?

The heattransfer from the emitting surface (radiator/UFFH) depends on the "Delta T". Which is the difference of temperature between the emitting surface and the room temperature. Not per se on the flow rate of the circulated water.

Going for a pessurised system versus a vented system safes on the third storey (the attic) which would be heated paralel with the rest of the house. Via plumbing and feeder tank because warm water rises upwards, it's thermal energy content wasted up there where it isn't needed. Via the gaps in the attic insulation creating cold spots on the ceiling, the insulation material should be left away between ceiling plasterboard and the bottom of the feeder tanks to avoid them freezing.

If using automatic air valves for 'bleeding' the system, the radiators a min. pressure must be maintained, check the manufacturer's information.

The pump's propellor speed must be set high enough to avoid the boiler running in an on-off modus. This can only be achieved if the thermal energy created by fuel combustion is transported away fast enough. Otherwise the boiler switches permanently on and off, an inefficient fuel usage would be the result.
Here the built-in electronic controled pumps have a big advantage, in combination with a modulating boiler the combustion could be run 24h/24h at the lowest possible fuel consumption.

About retrofitting existing boilers with the electronic controlled pumps: not all boilers readily take the new pumps. The circuit board might get overheated. A good plumber/electrician will alter the existing circuit board to make the new pump fit. Some existing boilers however can be equipped straight away with the new pumps.
Check this with the boiler manufacturers, send them an e-mail describing the boiler and the new pump planned to be installed.
Alternatively ask them for a new circuit board suitable for the new pump.
Fitting unsuitable equipment to a boiler will nillify the manufacturer's guarantee. It would be up to the plumber to take the risk, so better ask the boiler manufacturer for written information.

yoshytoshy

As a matter of interest ,what power consumption is a standard pump ?
Are we talking a few watts here ?

I checked it out myself ,we're talking 30watts maximum of a difference here.

Put that against the cost difference and it's harmless on a standard domestic system.

heinbloed

Yo****oshy wrote:

As a matter of interest ,what power consumption is a standard pump ?
Are we talking a few watts here ?

I checked it out myself ,we're talking 30watts maximum of a difference here.

Put that against the cost difference and it's harmless on a standard domestic system.

I'm not sure what you mean. The potential energy safings when swapping the old pump for a new electronical controlled pump are given in the charts published by the various manufacturers.
For standard household situations the average financial amortisation time is somewhere between two - three years as far as I can see.
Since most old pumps are oversized (as the old boilers) it could be much better.

The Scandinavian manufacturer had advertised an average amortisation time of 2 years with standard household electricity tarif. With an expected lifetime of at least 12 years this would pay 6 times for a new pump.

yoshytoshy

heinbloed wrote: »

The potential energy safings when swapping the old pump for a new electronical controlled pump are given in the charts published by the various manufacturers.
For standard household situations the average financial amortisation time is somewhere between two - three years as far as I can see.
Since most old pumps are oversized (as the old boilers) it could be much better.

The Scandinavian manufacturer had advertised an average amortisation time of 2 years with standard household electricity tarif. With an expected lifetime of at least 12 years this would pay 6 times for a new pump.

Sorry you've lost me there, english charts are the ones I was looking at with regards to energy usage.
There wasn't any mention of amortisation ,just simple charts as to energy usage.
Having installed thousands of domestic heating pumps ,I can safely say that the less electronics the better.
I certainly wouldn't be concerned about 30watts of difference for a typical period of usage.

heinbloed

@yoshytoshy:

Maybe you should check the charts of the manufacturers yourself. I think what you're looking for can be found there in English as well. Wilo and Grundfoss brochures are available in print at your local plumbing store. They do contain charts, in English.
But to compare like with like one needs more than advertsing material. Check the manufacturer's homepages for detailed information. A height/head of 6 meters for example doesn't have be met with every installation. So a new pump might be chosen even smaller than the charts comparing like with like, 'head with head' so to speak.

How much of the anual electricity consumption is caused by central heating circulation pumps? 10% ? 20% ?


You say :

I certainly wouldn't be concerned about 30watts of difference for a typical period of usage.

30 Watts difference - what do you mean by that ? And what does "concerned" mean in this connection? Do you pay the electricity bills of the pumps?


Do you have a sample, a calculation? Something official or other data gathered privatly?
It would be interesting to see where your assumptions are contradicting scientific research done for the EU energy comissioner, see the link further below ....

That a standard C or D or E rated pump has a minimum consumption in an existing central system because it simply can't be adjusted to a lower consumption doesn't mean it is pumping the optimum l/minute for the system. Most 2 or 3 stage banger pumps consume between 40 - 120 Watts (per hour).

And most of them run at the max.possible output/electricity consumption to reduce the boiler's cycling. To save on combustion fuel.

So comparing a 12 Watt/h modern pump with 120 Watt/h banger and 3600 running hours per year:
Either one pays to run the circulation pump(at an average household electricity price of € 0.152 per kWh)
€ 6.57 per year for electricity consumption or € 65.66 !

No more questions I guess.......(a difference of €59.- in the anual electricity bill that is).
The new modern pumps cost around € 150.- to purchase and around €50.- to fit.

So the pump saves it's own investment within about three years. Just for the electricity it consumes less.
But since these pumps are modulating and help to avoid boiler cycling they safe on the combustion fuel as well. They extend the boiler's life time and reduce the soot in the chimney.




The technically outdated banger pumps are usually not automatically modulated, so no matter how much pressure is demanded they always operate at maximum set output. If only 1 radiator has to be suplied or 12 radiators, these outdated pumps run on maximum level.

Changing thermal demands do need modulating pumps. So the demand can be covered energy efficient. To spare the valet and the environment.

Modern (household) circulation pumps use 8-12 Watts per hour. Provided they are installed by competent plumbers. There are now also 1 Watt pumps available, for each radiator it's own mini-pump.....


The efficiency of electric energy usage is increased by 5-8 times.
This is about the easiest way to safe on electric energy, on money. Without any comfort loss the household's electricity consumption can be reduced by 10-20 percent.
And the CO2 emissions.
The installation of these pumps on a mandatory level would have safed Ireland's taxpayers millions.
But the installers wheren't concerned about this I assume.

The pay-back time (the amortisation) with the average household is faster than any other change in electricity consumption, be it energy efficient lightning or the A-rated fridge. The A-rated boiler or the Energystar computer screen.
The change to the efficient circulation pumps has propably the fastest amortisation of all measures. And the longest lasting as well.
Before buying 40 energy efficient bulbs it's propably more worth it to invest in an efficient circulation pump. It costs the same, pays back faster and lasts much longer.

The incompetence of the plumbing industry to install efficient central heating systems has caused the EU to act.

See

http://ec.europa.eu/energy/efficiency/buildings/buildings_en.htm

Not only by demanding labelling the boilers but by banning inefficient circulation pumps. For the industry the A-rated pumps are made mandatory.
For the households they'll become so soon I suppose.

If we keep the Building Energy Rating system for the future certainly the electric energy consumption of the circulation pumps/central heating systems will be included in the rating.

What many haven't realised is that these outdated pumps are used in Solar Thermal systems as well. I saw recently a circulation pump in a ST system consuming a bitter 40 Watts per hour.
And ST systems becoming mandatory in modern and modernized buildings and the wet central heating still allowed we have 2 bangers per household with thousands of running hours per year.
These circulation pumps consume peak hour electricity.
As soon as intelligent metering comes into effect ( where the consumer isn't charged a flat rate anymore per kWh but real market prices) these old circulation pumps will be a very heavy burden on each household.

PS
Another link:

http://www.energypluspumps.eu/en/data_editor/File/Finalreport.pdf

yoshytoshy

heinbloed wrote: »

@yoshytoshy:

Maybe you should check the charts of the manufacturers yourself. I think what you're looking for can be found there in English as well. Wilo and Grundfoss brochures are available in print at your local plumbing store. They do contain charts, in English.

I've said I checked it ,it's not like I wrote an essay and said so in the middle.

There are charts for power consumption on the grundfos site.