Hanksy

Latest update now really cold weather has hit us and some reasonable data points now in Sweet spot for heating is 4 degrees and above. Once you hit 3 for any length of time elec usage rises sharply.At zero degrees pretty much all day and night running costs are £5.45 day pellets would be £4.48. Suspect its defrost cycles causing the increased usage. Plus point however is that as they are 4 separate units they defrost at different times so you don't notice any heating drop. Running pellet boiler this week now to confirm usage of pellets is as I remember Overall still way cheaper to run than pellets but looking to maximise savings so hybrid running may well be the best solution overall. That said wouldn't be upset running A2A full time if didn't have pellet boiler in.

Quick update now turned really cold here -2 last night 0 in day £4.65 total cost for the 24hrs Still pleased overall 94days in now

Quick update on running costs so far Average/Day now £1.01 over 73 days Actual running costs chart added (aug only last 2 weeks) Currently saved over £90 by not using biomass boiler in 73 days Still rally pleased with performance and costs

Hi Iceverge it’s a Flir E5 unit but I got it with a tweaked firmware so it has the resolution of a much more expensive one. Flir use the same imaging chip in all the pro units they just cripple their resolution with sw. ebay had some modified ones a while back but haven’t checked recently though

Also have a nice thermal pic of conservatory unit in operation

Just a quick update now data is growing a couple of charts showing average cost per day V's night temps and one that inc kWh's used. General observation - still very efficient overall running costs now average £0.89p per day (up from 79p/day) pellets would have averaged at 3x this cost so very pleased.

Hi severnside I will try to answer your questions below 1. Start up is very low they are all inverter units and as small units biggest is 5kW when running all of them consume less than 1.5kW on a cold night so far. Pp depends on where you live here no issue but supplier should investigate all that for you if it’s needed and deal with it. 2.not turned it off since installed it’s on 24/7 at24 degrees so can’t really answer but it can kick out some heat if required so would not see it as an issue if off for awhile 3.we have gravity drained needs an external wall or a corner next to external wall pumps make a noise for about3-5seconds every 15-30mins I would find it annoying in a bedroom I think. 4. Total cost for all 4 units (these are top of the line units) inc power supplies etc etc was just under 10k from Midland Air Conditioning a very professional outfit they travel all over as well. I did get lower quotes but was lower spec kit and cheaper brands the company’s reminded me a bit of used car salesmen if you know what I mean. Also comes with 7 year warranty. service as domestic is only every 2 years as well with them (they do a lot of commercial installs eg Birmingham Bill ring etc). hope that helps

Sorry forgot to post the solar edge 6kW data as promised. Don't have an easy way to add the other PV 2 images 2021 to date and 2020 only installed in November

Hi Chris see below for answers as best I have so far 1. why switch - Brief history No gas in Village (north Shropshire) was on Anthracite boiler 2K+pa running cost. RHI came out so fitted pellet stove in place of anthracite boiler had for 7 years RHI finished in April this year. Pellets were costing me c1200pa (4 tons). Been looking at ASHPs as house is well insulated. Then we had the warm weather and house was too hot which led me to A2AHP's so we could have free cooling in summer as loads of excess PV. That really was the logic. Oh and to top it off wife has MS and so cannot fill boiler and she pointed out if I died she would have to move as cannot do the heating! using heat pump at least solves that one ? 2.Why A2A - Cooling in summer, If one unit fails still have 3 working so heat/cool still works, efficiency of the Mitsubishi units is really good and have a great installer in Midland Air Conditioning. Too many cowboys out there just wanting your cash without the skills and service to ensure a good solution. Didnt need water heating as solar thermal and PV. 3.Where - North Shropshire SY13 area not particularly warm 4.Hours a day - 24/7 its just on and set to 24 degrees on every unit 5.PV has covered all the running costs so far apart from £1.91 if we used it all 100% for heating . Reality is it is used for other things too eg car charging water heating etc but it has definitely contributed. In my figures I have assumed zero input from PV so just raw imported energy costs The AC total cost is simply total kWs used x elec rate. 6. PV array - had 3.7KW at start of fit then added further 6.3kW last year. really pleased with it. Will attach a graph showing the6 kw garage array for the last year easy as on app) overall winter is generally poor but it really depends on how many dull days we get eg dull overcast day typically 6Kw day sunny winter day c16kW day (summer 60kW/h day regularly). For me well worth outlay especially if you have an EV and or battery storage (we have both). 7. Prediction - I only have data on temps so far lowest is 5 degrees that's averaging at £1.33, 6=£1.22, 7=£1.15, 8=£1.06 will get more accurate as number of days at that temp increases 8 Heat calc - Sorry no I used my EPC to estimate heat and water loads Will post updates each month no problem Hope that helps

I have had 4 Mitsubishi LN A2AHP's installed roughly 2 months ago. they total 15.5kW output (2x5kW Kitchen and conservatory, 3.5kW in lounge and 2.5kW in main bedroom - we are in a bungalow 120sq/m). My heat load for the property is 12,500kw and water 2000kw. Until these were fitted I was running a pellet boiler for the past 7 years typical pellet cost was £1200pa I have been logging my daily running costs and room temps since the A2AHP's have been installed and comparing costs to pellets. From what I can see so far (only end Aug/Sep and uptown today) the running cost is averaging 79p a day (elec cost is19.3p/unit btw) Observations Temp set at 24c on all units (wife has illness needs high temp) all rooms in property achieve 23.5c or above. The airflow via the 4 units flows into other bedrooms, bathroom etc. I honestly thought we would need another small unit to balance the heat in all rooms but so far this clearly is not needed. running costs are very low in 65 days saved over £75 over pellets. Heat is far more comfortable than using boiler/rads stays very even No draughts or noise as always on they just tick over. Also the Mitsubishi LN units have a built in thermal camera that is used to detect people and can direct the airflow so that it doesn't blow on you (or you can set it to blow directly on you if you like) this also works as you move around the room really good feature. Down sides 4 units outside - you need the space for them or use a multi split unit ( I was advised against this as I had space - with one unit all internal units are on either heat or cool, with separate units you can mix and match eg 1 heating with 3 cooling etc etc. Also if one outdoor unit fails unlikely but possible the other 3 can continue to heat/cool) Cost wise only a few hundred quid between a multi split and 4 separate units. Water heating not possible with A2AHP - we have solar thermal and 10KW of PV so water heating is covered for us but something to consider if going this way. Below is a snapshot of my summary data I plan to continue to monitor for the full 12months and extrapolate the data to be able to predict my running costs based on outside temp eg 6 degree = £1.10 day, 12 degrees = 60p/day etc Feel free to ask any questions I will do my best to answer them.