Air Source Heat Pumps

albyota

zeupater wrote: »

Hi

Commissioning service ... my mistake, wrong link, but, from checking a wellknown distributor website it looks like AEI commissioning is available for <£400 anyway.

I dont think that I could find an installer who would accept zeupounds, they're only legal tender in the zeuhouse, we'd need to use a 'foreign' currency if we bought a unit and account for the purchase as an import which would show a negative balance of trade for that month ... if you accept zeupounds then i'll envoke a little quantitive easing and print a few then have an ASHP tomorrow if it suits .....

I follow the logic regarding the additional costs, however, what's to stop the system being fitted as a replacement for, or even, alongside an existing gas boiler ? ... also, why would you need to change the system to unvented, it could already be unvented, or couldn't it run on a standard vented setup ? ... again why £600-£900 for a cylinder, I'm not in the trade & could buy a twin coil copper solar 210l cylinder for <£350 and add a 3sqm coil for <£200 the last time I looked, so it should be £600max and this could already be in place if well planned with a solar thermal install ... I have a 28mm magnaclean unit on the circuit already and many others would have filters too, I'd guess that I wouldn't need two either .... the circuit is S-Plan, already has all control gear and was modified to have a bypass valve fitted when the HE boiler was fitted less than two years ago ... the install of the replacement gas boiler took two days of a gas fitter/plumber and probably a couple of hours of an electricians time (+apprentice) and included rerouting the boiler pipework and the fitter bricking up the floor mounted boiler's balanced flu hole and all this was done for thess than £2k inc VAT, so roughly £1k to cover labour/overheads and margin for the company.

Regarding the volume of the tank, what about a 210l tank with a 3sqm coil to compensate, or alternatively just having using a finned coil ? ... anyway, it makes very little difference to most, a 28mm diameter tube coil with a 3sqm surface area would be 34.1 metres long and displace 21l, so let's call a 210l tank 190l capacity, a reduction of only 10% (more on a smaller tank, less on a larger one) ....

Margin of 30% ? ... well that's probably okay when selling something with a price similar to that of a TV, but the installers who will survive when RHI matures will be those who soon discover that when selling items which cost the same as a small car, it's probably a little advantageous to reduce the margin which they were used to on cheaper heating boilers, increase sales, expand and make more profit rather than be uncompetitive, sell very little, and go to the wall :whistle:.

Z

Supply and Commissioning, is possible on third party installations, (caveats would apply), but we have to be careful that a system is not being fitted in the wrong application. I wonder, if zeupounds have the same transfer rate as the albypound + one chicken .

I would take each system on its own merit, as most of the time, the end user, is not heating system /componet savvy, so to install a new system onto to existing setup using existing old motorised valves / pumps etc, is a recipe for disaster, and we would be being called back as soon as a component (not fitted by us) failed.

Yes, a system can just be fitted to an existing system as you describe yours, and can be fitted to any cylinder....vented or unvented, as long as you know where the line has to be drawn as far as responsibilities/problems goes.

You describe an installation of replacing your boiler only two years ago, I think you'll find that 2 years ago, most businesses costs were lower, since then, Electricity, Gas, Insurances, Diesel, copper pipe, fittings, and labour have all increased.

You only picked up the 30% markup, but I said between 22% and 30% as figures to explain why the total cost of an average installation is what it is, it all depends on the total cost, some as low as 15%, also do 'mates rates', with other trades, but a professional company has to make a profit, (otherwise, whats the point in employing people for 14 years) and thats one of the reasons we are still able to return to site FOC if a system has an issue. (as opposed to riding off into the sunset never to be heard of again:eek:).

HTH

AL

albyota

TiredGeek wrote: »

Little bit off topic question here: what size pumps would you specify for the Ecodan 14kw units?
I have four 15/60 Grundfos Alpha 2L feeding the two ASHP on 28mm pipe and can only achieve ~25 L/min flow rate.
Short pipe runs, low loss header, two pumps per ASHP, so no restrictions really.
Obviously that's on the low side of what Mitsi specify for the units, 20 - 40 L/min, so I was wondering if my pumps need upgrading to something more like 25/60 to get a better flow rate.....
15/60 is what the installer say is right btw.

Mitsubishi do give guidance for pump sizing, however, on a standard heating one unit system, but ultimately, it is down to the installer to calculate and design correctly, and adjust accordingly, without knowing the layout and pipe runs, I can't comment. But the 14kW units certainly perform better with 40L/min.

AL

shazworth

Hi I have a Ice energy heat pump, it kills the electric, don'y know if the settings are wrong but it's costing me more than my other home with gas and electric, I am putting in more! I was told when I moved into this house by the housing that the Ice pump is energy efficient! I live in 4 Bedroom town house. I thought it probably would cost the same as my prevoius house which was a 4 bedroom home. I know it's the heat pump as in summer it's great. In my previous house I was putting in £30 electric and £10 gas sometimes more in colder weather. This house I put in £40 though out summer (it was a wet summer so I used tumble dryer as I do now) I continued to put £40 in and towards the end of summer I had nearly £70 in the meter. The meter is a prepayment one and takes £6 a week for debt and standing charge, Tuesday this week I put in the meter £45 and by tomorrow I am going to have to put another £10 in, its not even cold! I think the settings are wrong but how do I change them? I have changed it as it was cold on the top floor and the radiators thermostat had been turned so that they are on but no heating I had to change the heat slope settings. Now we have heat, but why did it take so much electricity when the heating didn't come on? arghhhh
Does anyone know the ideal settings? Please?

thanks

zeupater

shazworth wrote: »

Hi I have a Ice energy heat pump, it kills the electric, don'y know if the settings are wrong but it's costing me more than my other home with gas and electric, I am putting in more! I was told when I moved into this house by the housing that the Ice pump is energy efficient! I live in 4 Bedroom town house. I thought it probably would cost the same as my prevoius house which was a 4 bedroom home. I know it's the heat pump as in summer it's great. In my previous house I was putting in £30 electric and £10 gas sometimes more in colder weather. This house I put in £40 though out summer (it was a wet summer so I used tumble dryer as I do now) I continued to put £40 in and towards the end of summer I had nearly £70 in the meter. The meter is a prepayment one and takes £6 a week for debt and standing charge, Tuesday this week I put in the meter £45 and by tomorrow I am going to have to put another £10 in, its not even cold! I think the settings are wrong but how do I change them? I have changed it as it was cold on the top floor and the radiators thermostat had been turned so that they are on but no heating I had to change the heat slope settings. Now we have heat, but why did it take so much electricity when the heating didn't come on? arghhhh
Does anyone know the ideal settings? Please?

thanks

Hi

Welcome to the forum ....

Leaving the heatpump itself aside, the first place I'd start is with the pre-payment meter. Make a note of the kWh used and the monetary usage and then check the cost/kWh which you are being charged, remember to allow for the £6/week debt and standing charge and check that there's nothing really obvious such as the meter tariff not being configured correctly.

From the position of anyone being able to help with the heatpump, it's probably better if you could provide some information on the energy usage, not the value of the energy used, along with information related to what settings you currently have, room temperatures, flow temperature, domestic hot water temperature etc ....

HTH
Z

berniandbob

I am working my way through as many of these posts as possible. We live in Austria, in the mountains, so pretty cold all through the winter, and after building a new house, decided to go with ASHP system.
So far it works well and overall we are happy with it. We have underfloor heating throughout the house, triple glazing, and SO much insulation its almost ridiculous! My querey is regarding the defrost cycle of the system.
How often should it defrost, as ours seems to go into this mode frequently. I have asked the manufacturers to come and check it out HOVAL, but any thoughts or experiences would be very welcome.

richardc1983

berniandbob wrote: »

I am working my way through as many of these posts as possible. We live in Austria, in the mountains, so pretty cold all through the winter, and after building a new house, decided to go with ASHP system.
So far it works well and overall we are happy with it. We have underfloor heating throughout the house, triple glazing, and SO much insulation its almost ridiculous! My querey is regarding the defrost cycle of the system.
How often should it defrost, as ours seems to go into this mode frequently. I have asked the manufacturers to come and check it out HOVAL, but any thoughts or experiences would be very welcome.

As mentioned above, there are many variables... outside air temp, compressor run time... humidity levels... heating load...

IMpossible to tell. The system monitors the temperatures of refrigerant flowing through the system if this drops to below a certain level a defrost cycle will be performed.

You are best off checking if you can see visible ice or frost on the back of the coil as soon as it goes into defrost cycle.

[Deleted User]

berniandbob wrote: »

I am working my way through as many of these posts as possible. We live in Austria, in the mountains, so pretty cold all through the winter, and after building a new house, decided to go with ASHP system.
So far it works well and overall we are happy with it. We have underfloor heating throughout the house, triple glazing, and SO much insulation its almost ridiculous! My querey is regarding the defrost cycle of the system.
How often should it defrost, as ours seems to go into this mode frequently. I have asked the manufacturers to come and check it out HOVAL, but any thoughts or experiences would be very welcome.

What make is it?

Still way to warm here for it to go into defrost here...

Cheers

berniandbob

Its a Hoval Belaria system.

lovesgshp

berniandbob wrote: »

Its a Hoval Belaria system.

Just had a quick look at the UK website. Looks like a relatively new system, as only marketed under the Hoval name since 2008. May be best to check with the supplier as you have done, for their view.

gterr

Hi there,

Not sure if anyone can help. We have a Worcester Bosch Greensource 9.5kW ASHP which runs U/F heating downstairs and radiators upstairs. Don't know if this is standard for heat pumps, but the Greensource indoor unit has a "Rego" computer thingy with a million adjustable settings, including a heat curve which means the flow temp increases as the outside temp decreases.

For best economy we've been advised to set the heat curve to have a flow temp of 20 C when outside temp is 20 C, ("V")and a flow temp of 55 C when the outside temp is -30 C ("H", theoretical, obviously). This setting works fine for the U/F heating, and the domestic hot water is about 50 C which is also fine, but we are having difficulties getting a constant supply of warm water to the rads: we just get the odd burst of tepid water from time to time when the rads are demanding heat (TRVs fitted).

If we change the heat curve to V=30 C, H=60 C, we get sufficient warm water to the rads, but Worcester advise we will be losing some efficiency at this setting.

We notice that there is a mixing valve close to the U/F heating manifold and this is set to 50 C. Is this is to decrease the temp of the water sent to the U/F heating coils? If so, is this temperature appropriate, and might adjusting this value allow more warm water to the rads at a lower flow temp setting?

This mixing valve might be a red herring. There are so many other things to try that I am a bit bewildered. For instance, we have an indoor temp sensor in the hall which "influences" the way the Rego unit performs. We can increase and decrease the influence of this sensor. (And I don't even know why we have this, since every room downstairs has its own programmable timer+thermostat, and the hall is anyway always the warmest place because most of the heating coils pass through it on their way to other rooms.)

Any thoughts would be most welcome!