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View Full Version : How to increase performace of Altherma LT heat pump ?







dani146
22-10-2012, 04:50 PM
Hi,
I am using the Daikin EKHBX016A (indoor) + Altherma ERHQ016 (outdoor) LT heat pump system to heat my 290 sqm house. After solving setup problems left by the installing company (monthly costs of ~545 at temp. ranging from - 8 to - 17 degrees C) I managed to get as much as I could from my setup. I have now a monthly bill (in very cold days) of ~165.

Since winter is closing fast here, I decided to try and improve the system as much as I could.
My question is if anyone here knows a way to increase efficiency in the Altherma LT heat pumps.
I wanted to build an electric heating system powered by small solar pannel and place it on the wall behind the outside unit or under the unit. Will this help lower the electric bill ?

Thank you and sorry for my English :)
Daniel M.

ΜΑΝOLIS
22-10-2012, 06:29 PM
Good evening Daniel. i think you have to read first some thinks about that... Its a litle bit expensive and dificult in the begining actually you have to know some thinks about the solars.. It isnt only the instal (peace) but how to enginered it....

FRIENDLY
MANOLIS

dani146
23-10-2012, 11:28 AM
Good evening Daniel. i think you have to read first some thinks about that... Its a litle bit expensive and dificult in the begining actually you have to know some thinks about the solars.. It isnt only the instal (peace) but how to enginered it....

FRIENDLY
MANOLIS

Hi, it was expensive since they did not setup the inside unit correctly. That part it is already solved ;)
Regarding solar energy - all my house was intended to use solar panels for the power it uses but at this moment my funds are not ready for that investment.

I was looking for some simple solutions that will help this heat pump system to be more efficient during cold days (- 10 degrees C and lower) and maybe make some savings :D.

wytco0
24-10-2012, 11:16 PM
Hi,
I am using the Daikin EKHBX016A (indoor) + Altherma ERHQ016 (outdoor) LT heat pump system to heat my 290 sqm house. After solving setup problems left by the installing company (monthly costs of ~545 at temp. ranging from - 8 to - 17 degrees C) I managed to get as much as I could from my setup. I have now a monthly bill (in very cold days) of ~165.

Since winter is closing fast here, I decided to try and improve the system as much as I could.
My question is if anyone here knows a way to increase efficiency in the Altherma LT heat pumps.
I wanted to build an electric heating system powered by small solar pannel and place it on the wall behind the outside unit or under the unit. Will this help lower the electric bill ?

Thank you and sorry for my English :)
Daniel M.

Assuming that your system is properly sized for your house and that your house is reasonably well insulated,
your bill still sounds a bit high to me although I don't have much experience, are you on a single price electricity tariff as its better to be able to heat the house any time there is demand rather than on timers.

I suspect the pre heating with PV idea wont work very well and won't be cost effective.

For my installation I have thought about trying to increase the temperature near the outside unit by making it brighter or trying to introduce some additional thermal gain from glass or mirrors but its just a thought at the moment.

Do you use you heat pump for heating or for DHW as well?

If your using it for DHW I have found that the default programs my installer programmed are not very optimal for the way we use DHW. I recently discussed this with Daikin and they recommended that I use the weather dependent set point (A symbol in the control panel) and also to set DHW on timers. I haven't set the timers yet as I am still trying to work out when is the best time the pump to heat water for us.

Other things are the normal ones of reducing temp in bedrooms etc.

nec0310
11-11-2012, 09:53 PM
Hi Daniel,

We design and install Altherma. We have install 100's. Your bill sounds very high even after changes to mention.
Our LT ERLQ systems will use 400 -1200 per year depending on setup. Every system we install is metered.
What is your system flow temperature (auto settings/manual) ? What heat emitters are you using?
What is the equilibrium temperature setting- see manual for settings value (this setting controls back up heater)?
What is your hot water temperature (Daikin tank)??

dani146
11-12-2012, 11:27 AM
Hi and thank you all for reply. I am sorry about delay but working desperate to solve some of this Daikin problems :)

This are my setup details:
2 x Daikin EKHBX016A indoor units
2 x Altherma ERHQ016 outdoor LT units

One is for heating and the other mainly for heating water for our daily use.
This one will also start helping the first unit if outdoor temp is below - 3 degrees C.

I use weather dependent set point for system flow temperature.
Am using floor heating system + same tubes inside some of the walls.
My house was built in 2009 and I was here every day and every minute :). It is concrete (25 cm) on first level on the ground and than 2 levels using 25 cm wide bricks. Insulation was made with 10 cm Rockwool stonewool. and on the roof (flat) I used 20 cm polyurethane foam.

I have attached to this post my settings for the internal units. The left column is the heat pump used mainly for heating the house and the right column is for the heat pump used for water heating + helping on cold days.

Big thanks for all your help and for this forum that helped me so far.

P.S. please excuse my English.


9850

dani146
11-12-2012, 11:30 AM
I forgot to mention that I use 7 Grasslin Feeling thermostats. and during the day I set them up to aprox 19 - 19.5 degrees and where I stay all day I set them to 20 degrees maximum.
Also at this moment I changed the flow temperature from 34 to 36 since no room reach the 19 degree temp.

matelodave
14-12-2012, 05:41 PM
We had an 11kw split LT system installed two years ago to supply heat and hot water to our 140m2 bungalow. We've got underfloor heating (Polypipe overlay on top of a wooden suspended floor which is ventilated to the outside but isn't insulated - the cost and hassle of pulling up the the floor just wasn't justified

The walls are brick outer, block inner with rockwool cavity insulation, the windows are upvc double glazed (about 10 years old) and the loft has about 300mm of rockwool insulation.

The outside unit is located on the south east side of the building and has the sun shining on it during most of the morning untill just after lunchtime.

We are at home all day and keep the stats on at about 18 degrees in the living rooms & bathroom and 16-17 in the bedrooms. We only heat the 200l domestic water during the day when the sun is on the unit and only to 42 degrees which is just about hot enough for our use with a disinfect to 65 degrees for ten minutes once a week, again during the day when it's warmer outside.

Each room has it's own stat (which I reckon is over the top) and the hydrobox weather compensation is set to 42 when it's 0 degrees and 25 when it's 25 degrees. The boiler is times to back by -5 degrees between 22:00 and 06:00. All the room stats set back by 2 degrees overnight as well.

The equilibrium point was set to -1 but I've just changed it to -5 to see what difference it makes as the back-up heater has been working a bit this last week or so in the very cold weather. We find that the house stays quite warm enough and we don't use any other form of heating.

My hydrobox settings are very similar to yours. We are totally electric and our electricity consumption for the past 12 months was 8000kw for all our energy needs (heating, lighting, cooking, washing including a tumble dryer etc) which I reckon isn't bad.

In the last 12 months electricity has cost us just under 800, but as the price has just been increased by about 10% we've recently changed a lot of our lighting to LED to try and mitigate the increase (700 watts of halgen spotlights is now 54watts of LEDs and, surprisingly, a lot brighter). By saving us about 7 pence an hour they should pay for themselves in just over a year (when electricty costs will no doubt increase again)

matelodave
14-12-2012, 06:01 PM
Just a note - we have tried setting the room stats back by 5 degrees overnight but found that the house cooled down too much and it took too long for the temperature to recover due to the low temperature of the underfloor heating. Yesterday our measured flow temperature was 33 degrees overnight when it was -3 outside and the daytime flow was 38 degrees when it was 0 degrees. The corresponding lounge temperature dropped to 16.3 degrees overnight and increased to 18.3 by the evening.

dani146
15-12-2012, 09:22 AM
system flow temperature (auto settings/manual) ? - I used auto but was not warm enough and if I set it at 34 degrees (from 10 to -1 outside) and at 35 (from -1 to...) it works better.

What heat emitters are you using? - under floor and inside walls heating emitters

What is the equilibrium temperature setting? I set it to -10 degrees

What is your hot water temperature (Daikin tank)? - Ariston 300 litters tank with temp set to 55 degrees (also has electric backup heater set to help from 50 to 55 degrees) and will only start to heat up on Friday so this will not draw back the heating function.

icecube51
17-12-2012, 11:30 AM
I think in both cases you benefit most if you go bi-valent. This means you have to add an extra heating device, like a wood-burner or fireplace. And if its possible a gas or oil furnace. Make them work together, like in good times the heat-pump, bad times the alternative.

You have the tech to make some savings, but if i have to live like that (20C and less) and look at the investment i made......... god bless the old fireplace.

Ice

matelodave
20-12-2012, 02:15 PM
As it happens, the 18-19 degrees is more than comfortable (even my wife who's the ultimate "chilly mortal" finds it cozy).

The underfloor heating distributes the heat all across the room, so there aren't any cold draughts and we dont get cold spots (except right up close to the windows) or red hot radiators. The room feels warm all over and the thermostats keep the temperature quite even due to the thermal inertia of the floor, unlike radiators which go hot & cold.