Moggaman Posted December 12, 2022 Share Posted December 12, 2022 Hi. Moved into my new build in July. Would appreciate some input. Daikin air 2 water pump with UFH down and up. 95sq m down and 95sq m up. heat kicked in around mid November .before that usage was about 11kw a day. currently we have a cold snap…minus 3 every night . I checked my meter this morning .. since 11pm last night to 8am this morning , 20kw of electric has been used.. now I understand the unit has to do extra work to go from -3 to the 20degrees the rooms are set at. Is it something that should worry me. House is very well insulated. I noticed when checking the meter reading outside at 11pm that the unit was extremely loud, louder than normal… is it defrost mode that is using the power?? thansk Link to comment Share on other sites More sharing options...
SteamyTea Posted December 12, 2022 Share Posted December 12, 2022 Right, there are a few of things. Is it a new build, if so, may still be drying out. How high is the flow temperature and do you keep the heating in permanently? Power is kW, kWh is energy, it is energy you pay for, not power. Do you use a lot of hot water, how hot is it stored at. How well insulated is your house, floor included? How does it match your heat loss calculations? It is 7⁰C down here on Penzance Promenade. 1 Link to comment Share on other sites More sharing options...
ProDave Posted December 12, 2022 Share Posted December 12, 2022 Defrost mode is quieter than normal on my unit. But different ones may work differently. To defrost mine seems to do the following. Stop the fan and the compressor. Actuate the 4 port reversing valve. re start the compressor only, not the fan. Run for a minute or 2 until the evaporator has warmed up and thawed (presumably using a temperature sensor) Once the evaporator has thawed, start the fan, and a puff of steam comes out. Stop the fan and compressor Revert the 4 port valve Start the compressor and fan for normal operation. It is a surprisingly quick operation, but it does draw heat out of the house doing so (more correctly sends chilled water to the house while doing so) Mine makes most noise when it is running flat out, compressor and fan at maximum speed, which is usually in the latter stages of DHW heating when the cylinder is nearing it's set temperature so the flow temperature from the ASHP is at it's highest. Some basic questions: Who built the house and how well insulated? What heats upstairs? Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 36 minutes ago, SteamyTea said: Right, there are a few of things. Is it a new build, if so, may still be drying out. How high is the flow temperature and do you keep the heating in permanently? Power is kW, kWh is energy, it is energy you pay for, not power. Do you use a lot of hot water, how hot is it stored at. How well insulated is your house, floor included? How does it match your heat loss calculations? It is 7⁰C down here on Penzance Promenade. Lots of questions that I don’t have answers to! House is well dried out how do I check flow temp? presume hot water heating is always on - not set to a time constraint ..again I presume I can check this on my indoor unit? house is hugely insulated… 150mm PIR under UFH… 120pir in walls and attic well insulated . im in the west of Ireland ! Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 11 minutes ago, ProDave said: Defrost mode is quieter than normal on my unit. But different ones may work differently. To defrost mine seems to do the following. Stop the fan and the compressor. Actuate the 4 port reversing valve. re start the compressor only, not the fan. Run for a minute or 2 until the evaporator has warmed up and thawed (presumably using a temperature sensor) Once the evaporator has thawed, start the fan, and a puff of steam comes out. Stop the fan and compressor Revert the 4 port valve Start the compressor and fan for normal operation. It is a surprisingly quick operation, but it does draw heat out of the house doing so (more correctly sends chilled water to the house while doing so) Mine makes most noise when it is running flat out, compressor and fan at maximum speed, which is usually in the latter stages of DHW heating when the cylinder is nearing it's set temperature so the flow temperature from the ASHP is at it's highest. Some basic questions: Who built the house and how well insulated? What heats upstairs? I managed the build … insulation is excellent. upstairs is set to 19… Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 I’m Wondering if that amount of kWh over the course of a night when it is so cold outside is normal?. I don’t have any concerns about the insulation . Link to comment Share on other sites More sharing options...
ProDave Posted December 12, 2022 Share Posted December 12, 2022 What I was getting it is radiators or UFH upstairs, or as we have, nothing because the house is so well insulated. Flow temperature should be easy to find on the indoor control panel. You want that as low as possible, radiators upstairs may force it to be higher. DHW can usually be on a timer but if not it will just re heat the tank when it needs to. Keep DHW tank temperature down to no more than 50C, Many of us find 48C is the sweet spot. Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 38 minutes ago, ProDave said: What I was getting it is radiators or UFH upstairs, or as we have, nothing because the house is so well insulated. Flow temperature should be easy to find on the indoor control panel. You want that as low as possible, radiators upstairs may force it to be higher. DHW can usually be on a timer but if not it will just re heat the tank when it needs to. Keep DHW tank temperature down to no more than 50C, Many of us find 48C is the sweet spot. UFH upstairs also… says 17l/per min on my Daikin indoor unit under flowrate ? Link to comment Share on other sites More sharing options...
PhilT Posted December 12, 2022 Share Posted December 12, 2022 52 minutes ago, Moggaman said: I’m Wondering if that amount of kWh over the course of a night when it is so cold outside is normal?. I don’t have any concerns about the insulation . Not bad for -3degC outside in a 190sqm property at 20degC inside. My old self build of 130sqm has about the same power draw so you are doing around 50% better than me! You'll get a better result by setting back a couple of degrees at night then running a bit higher during the day when outside temps are maybe 6degC warmer at the moment and the heat pump runs more efficiently with little or no defrosting. I go 18 night, 20 day 1 Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 There is an energy data section on the Daikin a2w indoor unit… tells me the average kWh for hot water heating last week was 6kwh per day… Link to comment Share on other sites More sharing options...
HughF Posted December 12, 2022 Share Posted December 12, 2022 20kWh/day with that m2 of floorspace, bargain.... Link to comment Share on other sites More sharing options...
Moggaman Posted December 12, 2022 Author Share Posted December 12, 2022 42 minutes ago, HughF said: 20kWh/day with that m2 of floorspace, bargain.... I’m not 20 though! Link to comment Share on other sites More sharing options...
SteamyTea Posted December 12, 2022 Share Posted December 12, 2022 (edited) 2 hours ago, HughF said: 20kWh/day with that m2 of floorspace, bargain.... Was 20 kWh for 9 hours. So about 53 kWh/day. That is about 2.2 kW of power, or 12W/m2. I am currently using about 18 kWh/day, which works out at 15 W/m2, and my temperatures are not as low. Edited December 12, 2022 by SteamyTea Link to comment Share on other sites More sharing options...
Moggaman Posted December 13, 2022 Author Share Posted December 13, 2022 20 hours ago, SteamyTea said: Was 20 kWh for 9 hours. So about 53 kWh/day. That is about 2.2 kW of power, or 12W/m2. I am currently using about 18 kWh/day, which works out at 15 W/m2, and my temperatures are not as low. How did you get 2.2 kw of power?. is the Air2water using most elec when the compressor is on or when the pump is on? Also, the compressors job is to work when the space calls to be heated, when the stat calls for heat??! I notice the pump is on all the time?. Is the pumps job to circulate the water around the UFH pipes, even when the compressor is off?? Sorry bout all the questions Link to comment Share on other sites More sharing options...
SteamyTea Posted December 13, 2022 Share Posted December 13, 2022 (edited) 1 hour ago, Moggaman said: How did you get 2.2 kw of power?. Probably badly You had used 20 kWh in 9 hours. As kWh is power (the kW) multiplied by time (the h), dividing by the time cancels itself out and makes the power the subject (what they used to say in maths lessons). So kWh / h = kW 20 [kWh] / 9 [h] = 2.222...... [kW] Rounding, or truncating, gives 2.2 kW. 1 hour ago, Moggaman said: is the Air2water using most elec when the compressor is on or when the pump is on? When the compressor, and the associated fan, is on, by huge difference. 1 hour ago, Moggaman said: Is the pumps job to circulate the water around the UFH pipes, even when the compressor is off? Yes. The ASHP controls may be monitoring the temperature difference between the flow temp and the return temperature, this is used to know if more energy is needed. Hard to do that if there is no flow and helps keep the system in the optimal range. Edited December 13, 2022 by SteamyTea Link to comment Share on other sites More sharing options...
joth Posted December 14, 2022 Share Posted December 14, 2022 We have a 1960s 151m2 property retrofitted to enerphit standard. Using about 8.5kWh per day for the last 10 days, think it's slowly crept up the 10kWh in recent days Link to comment Share on other sites More sharing options...
PhilT Posted December 14, 2022 Share Posted December 14, 2022 That's impressive, first time I've seen Enerphit, very interesting. The sub zero freeze didn't start here till Thu 8th - would be interesting to see your daily average since then. My son has just moved into a new Passivhaus with similar floor area to yours - would be interesting to compare Link to comment Share on other sites More sharing options...
Iceverge Posted December 14, 2022 Share Posted December 14, 2022 Passive House here in the south west of Ireland. Our heating in the last 2 weeks has averaged 20kWh per day for 185m2. Direct electric no heat pump. Just a single 1250w radiator on an inbuilt thermostat downstairs in the utility. It comes on at about 5pm and goes off at 8am. This equates to about 4.5w/m2 but the house is closer to 18-19 deg at night. This is fine apart from when you're sitting watching TV for a period or get out of the shower when it can be chilly. I might experiment with a fan heater in the bathroom if I get a chance. @Moggaman are you running a stove too? What airtightness reading did you get? What is the overall surface area of the house? 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted December 14, 2022 Share Posted December 14, 2022 28 minutes ago, Iceverge said: might experiment with a fan heater in the bathroom if I get a chance You trying to get rid of Granny. 1 1 Link to comment Share on other sites More sharing options...
Iceverge Posted December 14, 2022 Share Posted December 14, 2022 2 hours ago, SteamyTea said: You trying to get rid of Granny. That's a shocking suggestion 1 1 Link to comment Share on other sites More sharing options...
Moggaman Posted December 15, 2022 Author Share Posted December 15, 2022 On 14/12/2022 at 10:27, Iceverge said: Passive House here in the south west of Ireland. Our heating in the last 2 weeks has averaged 20kWh per day for 185m2. Direct electric no heat pump. Just a single 1250w radiator on an inbuilt thermostat downstairs in the utility. It comes on at about 5pm and goes off at 8am. This equates to about 4.5w/m2 but the house is closer to 18-19 deg at night. This is fine apart from when you're sitting watching TV for a period or get out of the shower when it can be chilly. I might experiment with a fan heater in the bathroom if I get a chance. @Moggaman are you running a stove too? What airtightness reading did you get? What is the overall surface area of the house? Hi. No stove. Didn’t do Airtightness test yet, but very confident it’s excellent . surface area is 190m2. In mid west Ireland . Link to comment Share on other sites More sharing options...
Marvin Posted December 15, 2022 Share Posted December 15, 2022 On 12/12/2022 at 19:39, Moggaman said: I’m Wondering if that amount of kWh over the course of a night when it is so cold outside is normal?. I don’t have any concerns about the insulation . We have 100m2 with more insulation than you. Here's December use. (minutes converted into percentage of hour) last night average -1 ASHP power Reading Reading Use Time Date Reading kWh diff 8.50 01/12/2022 2,467.40 2.92 17.00 01/12/2022 2,471.11 3.71 10.00 02/12/2022 2,478.40 7.29 23.00 02/12/2022 2,484.17 5.77 8.00 03/12/2022 2,486.72 2.55 23.25 03/12/2022 2,494.77 8.05 22.75 04/12/2022 2,501.00 6.23 10.75 04/12/2022 2,505.81 4.81 8.50 05/12/2022 2,508.68 2.87 22.45 05/12/2022 2,516.31 7.63 8.25 06/12/2022 2,520.08 3.77 22.45 06/12/2022 2,527.08 7.00 8.00 07/12/2022 2,530.31 3.23 22.60 07/12/2022 2,539.92 9.61 8.05 08/12/2022 2,543.33 3.41 22.50 08/12/2022 2,553.06 9.73 18.30 09/12/2022 2,567.02 13.96 22.50 09/12/2022 2,570.27 3.25 8.10 10/12/2022 2,573.59 3.32 18.00 10/12/2022 2,580.59 7.00 10.25 11/12/2022 2,589.35 8.76 22.70 11/12/2022 2,599.28 9.93 8.00 12/12/2022 2,602.92 3.64 22.70 12/12/2022 2,613.59 10.67 8.00 13/12/2022 2,614.40 0.81 22.90 13/12/2022 2,626.27 11.87 8.66 14/12/2022 2,630.05 3.78 22.75 14/12/2022 2,641.64 11.59 8.20 15/12/2022 2,648.26 6.62 Link to comment Share on other sites More sharing options...
JohnMo Posted December 15, 2022 Share Posted December 15, 2022 A a slight reality check, we are also around 190m2, but single storey so more exposed surface area to the outside. Also we hit -9 a few days, but generally we are putting 60 to 70kWh in to the floor measured by a heat meter. So if you are getting a CoP of 3 ish, your are in the same ballpark. (20,000W/24hr)/190m2=4.4w/m2 Multiple by you CoP say 3 at low temps. 13.3w/m2. So still as good as a passivhaus needs to be. It's just cold your house heat losses more heat. Link to comment Share on other sites More sharing options...
Moggaman Posted December 15, 2022 Author Share Posted December 15, 2022 17 minutes ago, Marvin said: We have 100m2 with more insulation than you. Here's December use. (minutes converted into percentage of hour) last night average -1 ASHP power Reading Reading Use Time Date Reading kWh diff 8.50 01/12/2022 2,467.40 2.92 17.00 01/12/2022 2,471.11 3.71 10.00 02/12/2022 2,478.40 7.29 23.00 02/12/2022 2,484.17 5.77 8.00 03/12/2022 2,486.72 2.55 23.25 03/12/2022 2,494.77 8.05 22.75 04/12/2022 2,501.00 6.23 10.75 04/12/2022 2,505.81 4.81 8.50 05/12/2022 2,508.68 2.87 22.45 05/12/2022 2,516.31 7.63 8.25 06/12/2022 2,520.08 3.77 22.45 06/12/2022 2,527.08 7.00 8.00 07/12/2022 2,530.31 3.23 22.60 07/12/2022 2,539.92 9.61 8.05 08/12/2022 2,543.33 3.41 22.50 08/12/2022 2,553.06 9.73 18.30 09/12/2022 2,567.02 13.96 22.50 09/12/2022 2,570.27 3.25 8.10 10/12/2022 2,573.59 3.32 18.00 10/12/2022 2,580.59 7.00 10.25 11/12/2022 2,589.35 8.76 22.70 11/12/2022 2,599.28 9.93 8.00 12/12/2022 2,602.92 3.64 22.70 12/12/2022 2,613.59 10.67 8.00 13/12/2022 2,614.40 0.81 22.90 13/12/2022 2,626.27 11.87 8.66 14/12/2022 2,630.05 3.78 22.75 14/12/2022 2,641.64 11.59 8.20 15/12/2022 2,648.26 6.62 Remarkable difference Link to comment Share on other sites More sharing options...
Marvin Posted December 15, 2022 Share Posted December 15, 2022 55 minutes ago, Moggaman said: Remarkable difference Yes. You said your building was very well insulated which means ours is super insulated? And others here are super super insulated. Having tinkered with our system (playing with your toy she calls it) and completed a few major alterations it's alot better than it was. There are reports that indicate recommendations to ensure the best result from an ASHP installation and we were very careful to follow them and improve them when installing the system including extra insulating any pipework or tanks and so on. This alone can make a good improvement. We also meddled with the weather compensation settings and now that has helped improve results. Link to comment Share on other sites More sharing options...
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