Altherma Optimal Peformance Setting

[rebellad]

Hi guys,

I have posted before after having issues with my Altherma uni but thankfully all is ok now. As we are coming into the winter I was wondering would someone be able to help mein setting the unit for the fothcoming cold weather. What I am looking for basically is time settings i.e when to have the unit on? Should it be on 24 hours a day or should it be on at night to make use of the cheaper electricity during and a few hours a day. Basically we are out of the house Monday - Friday from 7:30 to 18:00 and are at home for most of the weekend. Any help ould be greatly appreciated.

[brunstar]

It sounds like you are only in the house during the weekend.
The best way to run your system is to increase the room temperature with your external room thermostats during the cheap tariff and set back the room temperature during the normal tariff.
You need to do the same thing with the user interface too, increase the weather dependant set point during cheap tariff and decrease the flow temperature during normal tariff.
By doing this you can increase your power consumption during the economy time and decrease it during the normal tariff.

[freedom HP]

Your daikin installer should use the daikin software, in his design he will have put operating times. these times are what you should use.

my altherma is never switched off, this means it cruises slowly on all year maintaining the room temperature no matter what happens, this is the best way to run a heat pump. They are not great at rapidly raising room temperature so the best thing to do is let it cruise happily along at a lower room temperature. Its cheaper and more comfortable in the long run.

set up is the most important part of installing any heat pump.

regards

Graham

[rebellad]

THanks guys, Freedom HP if you don't mind me asking what have you your Altherma set to currently??

[styrman]

Hi

Wanted to ask the same about Altherma HT.:)

What settings do you have on your units out there...

I did notice though that there's not much point letting the temp down to much as it's time and energy consuming to bring it back....

Cheers

Robert

[freedom HP]

i run mine (an LT 8kW a superb machine) with floating temperature from 35-50C depending on ambient, 24/7 operated by a single room stat set at 19C room temp.

i get the unit to heat the tank at 3 am for 2 hours and at 3pm for 1 hour as well

altherma is really slow at heating the water tank, its the systems only real fault. The reason is the Daikin tank made by oso has a far too small coil in it. Im going to change it to a proper heat pump cylinder made by Gledhill. I have one of these running on my Samsung EHS system (similar to the altherma ) in the office, it will heat 210L of water from cold in 40 mins. The Daikin cant get near this performance.

If you use the Altherma with Gledhill tank it will also do the same.

if you want all the field settings for the altherma i will email them to you pm me

regards

Graham

[wozza]

I agree with all of the above especially Brunstar, have your system set back in the day and heat our water at night o make sure you are dojng majority of heating in off peak.

What heat emmiters are you using.

[rebellad]

Hi guys, thanks again for all the info here. I have one more question if you guys woulnd't mind please? How often should the unit be serviced and would anyone know a ballpark figure for the servicing??

[wozza]

rebellad,
With F-Gas it depends on how much gas your system has in it, if it below 3kgs your o.k. if its above i believe you have to have checked every 12months.
Not much to service really, strainer,make sure pressure is o.k., clean condenser

[styrman]

Hi, thank's for the info... however settings for LT will not apply for the HT. I have high heat radiators.
For now I have low temp set at -7 and water temp 65 then... high temp +18 and 50C set there...
Weather dependant auto adjusted water temp...
i.e @ 5C I get 56-58C and so on...
Normally we request 23C and have a night setting from 2300-0500 to 22C
As long temps are around 5C outside this works however needs som attention as the Altherma keeps running eventhough it reaches 23.3C Stops @23.5, and starts again @ 22.4C
Take some time to reach the last 0.2 in order to stop the pump. So we do do it by requesting 22C when temp is 23 or so.
Any of yoy that has used a HT in really low outside temp. works OK? What settings did you use?

Eventhough Altherma can reach 80C i would like to thing that it's wise and economic to keep it <70C.
Do not have a night / day tariff... electricity has same price 24/7..
Will try this so I know what times of the day the pump runs most before I consider any changes
:)

Robert

[rebellad]

Again guys thanks for the replies, very helpfully. Gonna go with one more question!! - what daily cost in kwh are people finding that there units are costing??

[brunstar]

With you question about running costs, this will depend on what flow temperature you are running at. Lower your condensing temperature and lower your running costs increasing your efficiency. If you go to the technical data you can have a look at your flow temperature for a given outdoor temperature and it will give you the power input which you can use to calculate your system running at this power input for a duration and it will give you your guide to costs. I hope this helps.

[rebellad]

With you question about running costs, this will depend on what flow temperature you are running at. Lower your condensing temperature and lower your running costs increasing your efficiency. If you go to the technical data you can have a look at your flow temperature for a given outdoor temperature and it will give you the power input which you can use to calculate your system running at this power input for a duration and it will give you your guide to costs. I hope this helps.

Thanks Brunstar, pardon my ignorance now but what do you mean "go to the technical data"??

[cultsmill]

Hello, I am new to this forum but have very similar issues.
I had an Altherma indoor unit (Hydro cube) and outdoor unit supplied and fitted in place of an oil fired boiler.We have uFH and have had no issues, until the Altherma was installed.
At present the unit has been running for 3 months, in the coldest part of the winter, we had a week of -15C and the unit could not cope. Now we are in the spring the ambient tempertaure is 8 to 10 C, can still fall to 0 at night, but the Altherma is still using 5kW per hour of the day which equates to 120kW /day or £576 per month. I cannot continue to use this amount of electricity and was hoping someone could advise how the Altherma unit should be set up.
The flow temperature to the UFH is 59 C, the return around 47 C and the room temperature is 24 C.
We don't want the room this hot but as the unit is working on "weather compensation mode" do I have any choice.
The unit was only fitted in December and the installer has to return to fit a buffer tank of 30 litre and a 6kW back up heater for when it gets cold next winter, but this has proved to be dificult as the installer has 80% of the invoiced price.
Not at all happy with the system but this maybe down to how the installer has shown a complete disregard to the issues raised.
Any help !

[Jon Glanfield]

Hi Cultsmill

Just a few questions if that's OK.

What size and type of unit is it i.e. low temp or high temp, I am guessing high temp from the flow temp?
What were the original design parameters in terms of the UFH and centres that the pipe was laid at?
Is it UFH throughout and if so screed/plate/dry mix?
Is the UFH zoned and if so are there any open loops?
Do you have additional pumps on the UFH manifolds?
Not sure I understand about the 30 litre buffer and back-up heater, is this a Daikin approved product?
Is the property new build, retro what are the insulation values and how was teh heat loss calculated?

If you can fill in some of this it will give a better idea of what is happening?

Jon

[sinewave]

OP it would be good to know the answers to the Q's asked by Jon plus the house size?



In the mean time some figures from my install.

We have a 16kw HT unit feeding a 6 bed, 4 bath 3 story house at 352m2 (3788ft2 in old money)

No under floor just oversize double convectors plus a few towel rads.

Wifey & Kids nail the bath & shower most days.

In these current UK temps our unit is using around 70kwh per day and around 2200kwh per month which equates to around £7.50/day £242/month.

I don't thinks that's bad my self especialy as we were on Oil before which at 60p/litre would've been a Killer right now! :rolleyes:

[brunstar]

Hello, I am new to this forum but have very similar issues.
I had an Altherma indoor unit (Hydro cube) and outdoor unit supplied and fitted in place of an oil fired boiler.We have uFH and have had no issues, until the Altherma was installed.
At present the unit has been running for 3 months, in the coldest part of the winter, we had a week of -15C and the unit could not cope. Now we are in the spring the ambient tempertaure is 8 to 10 C, can still fall to 0 at night, but the Altherma is still using 5kW per hour of the day which equates to 120kW /day or £576 per month. I cannot continue to use this amount of electricity and was hoping someone could advise how the Altherma unit should be set up.
The flow temperature to the UFH is 59 C, the return around 47 C and the room temperature is 24 C.
We don't want the room this hot but as the unit is working on "weather compensation mode" do I have any choice.
The unit was only fitted in December and the installer has to return to fit a buffer tank of 30 litre and a 6kW back up heater for when it gets cold next winter, but this has proved to be dificult as the installer has 80% of the invoiced price.
Not at all happy with the system but this maybe down to how the installer has shown a complete disregard to the issues raised.
Any help !

In relation to your installation your system is running when it does not need to as there are no room thermostats on the system, your flow temperatures are too high and this is no surprise that you have high running costs as the unit is running when it does not have to just cycling on flow temperatures.
You have to speak with your installer and distributor as this is the only way in which the system will function with lower running costs. If you have hot water make sure that this is also timed.
In the mean time drop the flow temperature on your controller and this will reduce the amount of energy consumed until a room thermostat is installed.
If you walk up to the controller and there is a fixed figure shown on the screen your system is not operating on a weather compensated set point.

[matelodave]

Hi there,
We've got an Altherma 11kW LT system fitted with polypipe overlay u/f heating. It's a bungalow of 140m2, cavity insulated walls, 270mm in the roof but the u/f is laid directly onto 18mm chipboard flooring over a ventialted cavity (not ideal, but the cost and aggro of pulling all the flooring up, insulating and relaying was more than i could bear).

The heating system replaced electric storage radiators (for which we have no cost info) and as there is no mains gas the only alternative was LPG or oil.

So far we are pleased with how the system is performing, it uses about 50kw/day when the average outside temp is 0 and about 25kw when its about 10 (monitored using a free British Gas Minimim energy monitor, which I reckon is over reading by at least 10% if not more).

The average temp in the house is about 19 which is quite comfy. each room has it's own stat and the Altherma is set to weather compensation setpoint at 42 degrees flow when it's 0 outside and 25 degrees when its 20 outside (soon to be shifted to 15). The Altherma controller sets back the flow temp by -5 degrees on the set point between 22:00 and 06:00. The 200l daikin tank is heated to 50C between 04:00 and 06:00 and that generally lasts the two of us for the whole day.

Out total energy consumption for the house (by the electricity supply meter) for Jan 2011 was 1330kw (£105) and for Feb 2011 was 1000kw (£83) and my annual projection is about 8500kw which I don't think is too bad. As we only had the system in and running from the beginning of November and we were away for the whole of December we are still trying to tweak it to maximise comfort and economy.

Perhaps someone could telll me the best way to set it for frost protection when away for prolonged periods in very cold weather - this is something I had a problem with and although I managed to turn it down to a flat 25 degrees and put all the house stats onto frost protection mode we still used about 900kw (30kw a day) in December although the house was unoccupied and everything except the heating and fridge/freezer was turned off.

[src100308]

Hi,

With regard to your 30 kw a day, despite the system been hardly turned on. Going on the basis of the reply to my posting:

http://www.refrigeration-engineer.com/forums/showthread.php?31928-Altherma-HT-ASHP-power-consumption-whilst-idle

I reckon that at least half of that 30kw will be standby energy consumption. My Daikin HT is using 5kw per day - doing nothing. Anyone know how to reduce standby costs?