canalsiderenovation Posted January 29, 2021 Author Share Posted January 29, 2021 17 minutes ago, AliG said: The heat loss should be the same other than slightly lower standing losses due to a lower average tank temperature. It may be that heating the water in the afternoon you are doing it at the warmest point in the day which would slightly improve the COP, but I wouldn't have thought the difference would be enormous. That's interesting. I guess I can keep monitoring it to see what happens. At the moment it's just about monitoring it each week and seeing what is having an impact. Link to comment Share on other sites More sharing options...
AliG Posted January 29, 2021 Share Posted January 29, 2021 You need 7.3 kWh to heat 150L of water from 6C to 48C. I think the original forecast was based on about 10kWh a day when the ASHP was installed. This will account for standing losses in the tank and pipework also which might be 1-2kWh a day. So I would divide 10 by the COP to get the electricity usage on a daily basis. Probably 5kWh per person in the house is a good estimate. 4.2kWh a day would raise the temperature of a 300L tank to 60C from 48C. But it wouldn't cool back to 48C every day, so it would probably be 2-3kWh a day for the immersion. Link to comment Share on other sites More sharing options...
Spoogster Posted January 29, 2021 Share Posted January 29, 2021 2 minutes ago, AliG said: You need 7.3 kWh to heat 150L of water from 6C to 48C. I think the original forecast was based on about 10kWh a day when the ASHP was installed. This will account for standing losses in the tank and pipework also which might be 1-2kWh a day. So I would divide 10 by the COP to get the electricity usage on a daily basis. Probably 5kWh per person in the house is a good estimate. 4.2kWh a day would raise the temperature of a 300L tank to 60C from 48C. But it wouldn't cool back to 48C every day, so it would probably be 2-3kWh a day for the immersion. Works out about the same. Agile has a number of price dips over the daylight hours, particularly after lunch where there is a considerable dip for a couple of hours. Doing calcs on Agile, which has suffered a bit in January, against Go I think Agile still wins out. It helps if you can seriously ramp the power use downwards 4-7pm, which I plan to do. Can offset that by ramping it up after lunch, but I appreciate ASHP may not react that quickly. Octopus Agile = a spreadsheet dream! Link to comment Share on other sites More sharing options...
NSS Posted February 16, 2021 Share Posted February 16, 2021 Had our SMETS2 meter installed today to enable switch to Agile as our fixed-rate tariff has just ended. New rate would have added circa £90/year to our bill so decided to give Agile a try. Spent the evening working out the optimum new program settings for the ASHP. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted February 17, 2021 Author Share Posted February 17, 2021 13 hours ago, NSS said: Had our SMETS2 meter installed today to enable switch to Agile as our fixed-rate tariff has just ended. New rate would have added circa £90/year to our bill so decided to give Agile a try. Spent the evening working out the optimum new program settings for the ASHP. Just waiting for changeover to Octopus for us on 26 February. Then we have to wait up to two weeks before we can change on to Octopus Go/Go Faster. Agile I don't think will suit us. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted February 19, 2021 Author Share Posted February 19, 2021 Another week.... Big difference this week. After a 'worse consumption ever' weekend on 13/14 Feb for the heat pump with minus temperatures and a bitter wind the 24 hr period from last Friday afternoon to the Saturday was a whopping 80 units for the heat pump. Monday - Friday this week has been so much better as soon as figures came out of freezing we also experienced our 'lowest consumption ever' in a 24 hour period - only 18 units for the heat pump. Average has been 26 units Monday - Friday this week With the electricity monitor I'm pretty content with our 'other' electricity use which averages at 7kWh a day. The coffee machine isn't too electricity friendly and the hob has an engineers visit next week as there is an issue (which may also explain the slightly high consumption when this gets turned on). Link to comment Share on other sites More sharing options...
TonyT Posted February 19, 2021 Share Posted February 19, 2021 Did you find out if there was a second immersion? Link to comment Share on other sites More sharing options...
canalsiderenovation Posted February 19, 2021 Author Share Posted February 19, 2021 27 minutes ago, TonyT said: Did you find out if there was a second immersion? I don't believe there is a second immersion. Link to comment Share on other sites More sharing options...
joe90 Posted February 19, 2021 Share Posted February 19, 2021 1 hour ago, canalsiderenovation said: Big difference this week. So it may well be that your high consumption is down to lack of insulation wen it’s really cold (you are still waiting fir your EWI if I remember? ?). Link to comment Share on other sites More sharing options...
canalsiderenovation Posted February 19, 2021 Author Share Posted February 19, 2021 1 hour ago, joe90 said: So it may well be that your high consumption is down to lack of insulation wen it’s really cold (you are still waiting fir your EWI if I remember? ?). Yep, and that won't happen until the weather stabilises and we can get it rendered at which point it will be spring and the weather will be warmer anyway - typical. I'm hoping the insulation has a significant impact! Other things like blinds/curtains in some rooms will also help (we have nothing at the moment)! Link to comment Share on other sites More sharing options...
SteamyTea Posted February 19, 2021 Share Posted February 19, 2021 4 hours ago, canalsiderenovation said: Another week.... Big difference this week. After a 'worse consumption ever' weekend on 13/14 Feb for the heat pump with minus temperatures and a bitter wind the 24 hr period from last Friday afternoon to the Saturday was a whopping 80 units for the heat pump. Monday - Friday this week has been so much better as soon as figures came out of freezing we also experienced our 'lowest consumption ever' in a 24 hour period - only 18 units for the heat pump. Average has been 26 units Monday - Friday this week So one where of the year where you have used an extra 270 kWh in a week. Divide that over the weeks in the heating season, say 30 weeks that is 9 kWh/week, not a very high price to pay. Link to comment Share on other sites More sharing options...
NSS Posted March 28, 2021 Share Posted March 28, 2021 Well we finally went live with Agile on Wednesday as the meter wasn't commissioned properly when first installed. Early days yet but already seeing a substantial (circa 30%) cost reduction versus Flexible Octopus. Link to comment Share on other sites More sharing options...
SteamyTea Posted March 28, 2021 Share Posted March 28, 2021 9 minutes ago, NSS said: Early days yet but already seeing a substantial (circa 30%) cost reduction How has your usage changed? Link to comment Share on other sites More sharing options...
NSS Posted March 28, 2021 Share Posted March 28, 2021 (edited) 1 hour ago, SteamyTea said: How has your usage changed? We have intentionally not changed our usage pattern (it was pretty disciplined already having reprogrammed the ASHP to suit the Agile tariff about six weeks ago), but cost saving for energy used against the old tariff is currently averaging just over 30%. That's only 3 days of data to date though. Edited March 28, 2021 by NSS Link to comment Share on other sites More sharing options...
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