Winter ASHP Runnings Costs So Far...

[Deleted User] · 30 December 2011 at 11:27AM

Update on 14kw EcoDan...

I know a lot of you are interested in winter running costs so for the last 31 days we used 1338 units for the whole house. Our tier two unit cost is just under 9p. So all in all very happy so far. House heated to 20c for 16 hours and not allowed to drop below 17c overnight. Energy hoggs also include non stop hair dryers for two ladies, a dozen outside lights, and being this time of year the oven is rarely off :mad: Also we had guests staying over so boosted the hot water a lot as the power showers can easily fill a bath!

Being Scotland we have had a mix of weather from snow to hard ice to semi mild. Which is the norm for here.

Any questions please ask?

bernithebiker · 30 December 2011 at 6:02PM

jeepjunkie wrote: »

Update on 14kw EcoDan...

I know a lot of you are interested in winter running costs so for the last 31 days we used 1338 units for the whole house. Our tier two unit cost is just under 9p. So all in all very happy so far. House heated to 20c for 16 hours and not allowed to drop below 17c overnight. Energy hoggs also include non stop hair dryers for two ladies, a dozen outside lights, and being this time of year the oven is rarely off :mad: Also we had guests staying over so boosted the hot water a lot as the power showers can easily fill a bath!

Being Scotland we have had a mix of weather from snow to hard ice to semi mild. Which is the norm for here.

Any questions please ask?

Interesting figures, and quite impressive.

I have a 10kW Sdeec in one of our holiday houses. Seems to be working very well so far. But it goes into defrost cycle when there is no frost. With an ambient temp. of about 8'C, I see no sign of frost on the exchanger at all. And yet, every hour or so, it does a short defrost cycle where the water is evaporated off the exchanger by a blast of heat.
When does yours defrost?
I spoke to Sdeec about this, and they said it's normal, and improves performance. I'm not convinced and I'll soon adjust some settings to delay these defrost cycles as much as possible.
Too early days yet to compare, but so far looks like we're saving a packet over the old LPG boiler.

hostlander · 31 December 2011 at 2:19PM

Hi,

Many thanks for your usage details, I thought that I would try and add some real world data too. I have been logging meter readings weekly.

We moved into a large house, around 350m2, in the Scottish Highlands, south of Inverness in September 2010, all electric, mixture of storage and panel heaters, chimney never used, house built in the 1980s, Skandia Hus design with triple glazing throughout.

We topped up loft insulation to 300mm, added an Aga Little Wenlock stove in January 2011 and then a Mitsubishi MSZ-GE71VA single split air-to-air heat pump in October 2011.

In December 2010 (was very cold and snowy) we used a daily average of 142 night units and 62 day units

In February 2011 (not so cold, stove in use) we used a daily average of 97 night units and 23 day units

During summer months of 2011, we used a daily average of 18 night units and 18 day units

In December 2011(similar temps to Feb 2011, now with ASHP and stove) we used a daily average of 37 night units and 40 day units

The house is kept much warmer now than last winter and we are saving around 18% on our overall electricity costs. All hot water is heated at night rates and we have one heavy duty electric shower, lots of computer and tv use, 5 living in the house.

I estimate that the ASHP consumes around 2 night units and 18 day units at the moment running between 6.30am and 11pm each day, air temperature has been in the range of -3 to +9 over the past month

[Deleted User] · 31 December 2011 at 4:54PM

bernithebiker wrote: »

Interesting figures, and quite impressive.

I have a 10kW Sdeec in one of our holiday houses. Seems to be working very well so far. But it goes into defrost cycle when there is no frost. With an ambient temp. of about 8'C, I see no sign of frost on the exchanger at all. And yet, every hour or so, it does a short defrost cycle where the water is evaporated off the exchanger by a blast of heat.
When does yours defrost?
I spoke to Sdeec about this, and they said it's normal, and improves performance. I'm not convinced and I'll soon adjust some settings to delay these defrost cycles as much as possible.
Too early days yet to compare, but so far looks like we're saving a packet over the old LPG boiler.

Hi, not aware of any defrosts and checked regularly when there has been snow/ice.

Just thinking about about running our old LPG boiler for the same length of time as the ASHP sends shivers down my spine :eek:

Ecokev · 1 January 2012 at 12:46AM

Unit should be running defrost at 8 degrees, something is set up wrongly

Ally74 · 6 January 2012 at 8:19PM

bernithebiker wrote: »

Interesting figures, and quite impressive.

I have a 10kW Sdeec in one of our holiday houses. Seems to be working very well so far. But it goes into defrost cycle when there is no frost. With an ambient temp. of about 8'C, I see no sign of frost on the exchanger at all. And yet, every hour or so, it does a short defrost cycle where the water is evaporated off the exchanger by a blast of heat.
When does yours defrost?
I spoke to Sdeec about this, and they said it's normal, and improves performance. I'm not convinced and I'll soon adjust some settings to delay these defrost cycles as much as possible.
Too early days yet to compare, but so far looks like we're saving a packet over the old LPG boiler.

I have the same problem with a 8.5kw Mitsubishi ecodan. Like yours it starts defrosting at around 8C. I had an engineer out who said it should not be doing it at those temps so he checked the sensors and one seemed to be ''way out''. A few weeks later after the part was delivered he came back out to fit it, this was just before the Xmas holiday period started, but it didn't fix the problem. I'm now waiting to hear back from him about any other solutions but i've been away for the past week at relatives. I'll report back when i hear from him again.

My running costs are nothing like any of the above. It may be because i live in a small 3 bedroom flat.
Air to water supplying 7 rads averaging 30 units a day (that's everything, i would estimate the HP is using around 15-20 units) Heating is on around 10hrs a day. I'm in South Lanarkshire Scotland.

bernithebiker · 7 January 2012 at 6:49PM

Sdeec insist that this is normal for mine. I can't believe it can be efficient like that. They have however given me the codes to adjust the defrost parameters.

When the refrigerant gets to -3'C it defrosts - I can drop this to a lower value.

Length of defrost - set at 5 minutes, I can drop this to 2 or 3 mins.

Frequency of defrost, set at 1 max every 40 minutes, I can up this to 60 mins plus.

If afterwards I see frost building up (Still haven't ever seen any yet), I can ease the settings back towards where they were.

[Deleted User] · 9 January 2012 at 9:23AM

Ally74 wrote: »

I have the same problem with a 8.5kw Mitsubishi ecodan. Like yours it starts defrosting at around 8C. I had an engineer out who said it should not be doing it at those temps so he checked the sensors and one seemed to be ''way out''. A few weeks later after the part was delivered he came back out to fit it, this was just before the Xmas holiday period started, but it didn't fix the problem. I'm now waiting to hear back from him about any other solutions but i've been away for the past week at relatives. I'll report back when i hear from him again.

My running costs are nothing like any of the above. It may be because i live in a small 3 bedroom flat.
Air to water supplying 7 rads averaging 30 units a day (that's everything, i would estimate the HP is using around 15-20 units) Heating is on around 10hrs a day. I'm in South Lanarkshire Scotland.

That's great consumption.

Unfortunately with 3m ceilings, 50% bare floors, detached, significantly bigger than our last three bed house and more windows than I can count its doing pretty well

Winter ASHP Runnings Costs So Far...

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