Revisiting an Air To Air installation: How Much Energy Has It Used?

This week I’m revisiting our recent installation of air to air heat pumps (and a slightly unusual hot water solution) to see how the customer has been getting on.
You might recall in a previous video that we completed the removal of this customers' complete gas fired central heating system and the retrofit of a whole house Daikin air to air heat pump installation. The system consists of seven Daikin FTXA Stylish units and two Daikin MXM series high efficiency outdoor multi split air to air heat pump outdoor units. We also installed a new - and cost effective - instantaneous hot water system by Japanese manufacturer Rinnai. The previous video is here for anyone who wants to catch up - • Air to Air Heat Pump: ...
I’m particularly keen to see how the whole system has fitted around the customers lifestyle and whether it has met their expectations so far. We will also be looking at the all important energy usage over the past couple of wintery weeks. Let’s hope I’m met with a warm welcome.

[@Paul-XCIV2]

Someone needs to make brick coloured ducting for the A2A installs.

[@gsum1000]

Good to see that Heat Pump AC units are gradually gaining ground. It's a pity the Gov. doesn't provide financial help with their installation.

[@starbuk138]

They are VAT free, which helps. Just no BUS.

[@richardlewis5316]

Minimal disruption, lower cost to install, heating and cooling and leave the combi and radiators installed for backup and hot water .

[@Metallifux5150]

House is lovely and warm says man with t shirt and two fleeces on😀😀😀

[@markramsay6399]

Nice video! Followed Mike for some time with his radio videos. Was very interested in the videos he / you did as we have a heat air to water system for the whole house. Very impressed with the install. Mark.

[@BenJandrell]

Great video... I'd love to see more videos from you as you're a great communicator. 👍

[@markgaudie80]

Really enjoyed watching this 2 part episode and Mike seems like a really top guy too. Nice to have lovely customers like Mike I’m sure Dameon. Loved the comment “had to snap the dog off a lamppost earlier!” 😂😂😂

[@gino2465]

Wow great video great chat and honesty, about heat pumps and talking Sence about a gas boiler.

[@jitheshak1]

Very nice video and great to see real world experience. Our Daikins always overshoots the temperature by 2 C and makes things very tricky to set, but we don't have this problem with Mitsubishi.

[@sjdiy8230]

Would good to see more content from your channel.

[@tonyfrewin4822]

I guess the true cost is a bit lower as he has some solar PV already installed so this looks like a really good choice. Nice well thought out installation and in my opinion, better than air to water any day.

[@kevinseymour3725]

Hi Very interesting couple of videos, so thank you. Our old electric immersion tank is on its last legs, so interested in the Rinnal as a replacement, wonder what showers are used?

[@darrenwalker6006]

Great information, could I ask what the usage has been over the past 14 days

[@CharlieStyr]

Not sure on the argument of "wasting" hot water that's heated to 60C for example when mixed down with cold water in a shower to say 40C... surely you need less 60C water mixed with cold for the shower vs just having a 40C flow of hot water? I guess there are losses in there and a hot water tank presumably loses more heat at a higher temp but still, I don't think there's as much waste as being suggested - please correct me if I'm wrong...

[@stevenfrazer46]

Hi Demeon, Great video thank you very much for covering this. We have a house which gets a big temperature differential during the extremes of the seasons, particularly summer. Will these systems also redistribute the heat around the property? And just to clarify, do Daikin allow some systems to tap one HP output to a hot water cylinder? their's or other manufacturers? Many thanks

[@lookoutleo]

Ive been given a 6kw Fujitsu Siemens air to air heatpump , now to find someone to do the pipe work :)

[@fredflintstone1428]

I'd love to know how the system faired over the period just before Xmas where we had -10C in Manchester.

[@gramamg100]

Great video. Have you had any experience with the Sunamp heat battery for water? Also like the fact I could keep my oil system in place until I’m totally convinced. Just out of interest what would a ASHP setup like that cost to have installed, Roughly.

[@fdsa3f3cas3w]

Got a quote for a 5 indoor unit, 1 outdoor unit of £13.5k - but routing the pipes is hard - are big with the insulation and need a pipe from each indoor unit to take to away water too.

[@peteg8920]

Decided to go air to air . How do the floor units compare to the wall mounted units ? My house is open plan and I have decided to replace a couple of radiators with unobstructed floor units. I think I would prefer the heat coming out at floor level but am uncertain if they are as price effective as the wall units.

[@97catalunya]

What about the water pressure of the hot water? We have a high pressure hot water tank and love the invigorating showers it gives.

[@jasonsanderson3612]

What were the total costs involved in changing over from the gas boiler/radiators/hot water tank system? Hence what is the pay back period?

[@richardlewis5316]

Why remove the combi and radiators and install air to air heating and cooling. Minimal disruption and cost and continuous hot water when needed.

[@hywelmackie255]

I’ve just installed Daikin air to air heat pump and plan to install a Sunamp heat battery for hot water. Has this been considered? I have PV and a house battery. I’m on Octopus Go tariff so charging the heat battery overnight in winter will be very cost effective.

[@adammiles526]

I had Mitsubishi Electric & Sunamp installed around Easter 22 following the PV and battery installation. Has been fantastic! Central heating stripped out, all rads gone and gas supply capped off. Very happy and it was coping well when it was -7 outside!

[@starbuk138]

What are the bathrooms like for temperature? I assume there aren't A2A units installed in the bathrooms, and doors to bathrooms often stay closed.

[@richardlewis5316]

Good point and how do we dry the mats and towels!! Radiators are a simple way to move heat around a house so all that is needed is a heat source to make them hot. ASHP systems do not seem to provide the flexibility of a simple combi boiler which can be on or off to suit the occupation of the house and the weather which in the UK can have frost in the morning and warm sunshine in the afternoon!!

[@leesmith9299]

i would have thought mixing with cold water just means less water needs to be heated so it's a zero-sum game. surely the inefficiency comes from losing heat while it sits in the tank but i think i heard him say that's minimal nowadays.

[@johnrush3596]

550 for the direct gas boiler compared to maybe solar with batteries and maybe a mixergy or sunamp ? It would be interesting to see the cost difference. Really interested to see the running costs over time but air to air sounds like a good alternative to air to water. The cooling aspect makes things really interesting.

[@richardlewis5316]

I have just posted a similar comment. My idea is to install air to air for heating and cooling and leave the combi and radiators in situ for back up and hot water. And no big tank to accommodate.

[@usefulrandom1855]

In regards to cooling, if you run your air con over summer as nice as it would be, surely you then just wipe out any savings made in winter though haha

[@richardlewis5316]

@@usefulrandom1855 I am in the UK so we could need A/C for about a week a year!

[@usefulrandom1855]

@@richardlewis5316 As am I , good point haha. Maybe a couple of days a day for a week over the year I suppose wouldn't make a dent a bills but would be handy for those rare very hot days.

[@richardlewis5316]

@@usefulrandom1855 A stand alone A/C is all that is needed for those few days when BBC News makes a temperature or 30 degrees sound like the end of the World!! I'm off to Dubai in a couple of weeks for just that - maybe 34

[@ovehansen7111]

Would have been great to have them comment on the comfort in the house, one thing I hate when travelling is noisy air conditioning units blowing in my face, what level of comfort does air-to-air units provide in the house, apart from the obvious heat?

[@gsum1000]

Our Samsung indoor unit produces a very low level of innocuous white noise when running at maximum heating rate. When the room is up to temperature the unit goes into low power mode and the sound is virtually inaudible.

[@RobFisherUK]

There are probably inefficiencies from heating water more than you need, but they don't come from the moment you add the cold water. See the first law of thermodynamics ;)

[@MrBradfordbiker]

He has a look that says, "I'm not getting any pv and it's a dear doo to heat with electric" 😂

[@MagicianMan]

Why a direct gas water heater like the Rinnai rather than a traditional "combi boiler" with or without Gas Flue Recovery Unit? What's the benefit?

[@effervescence5664]

Smaller, don't have to worry about a pressure gauge, heat losses from main heat exchanger to plate heat exchanger before heating hot water. That Rinnai is around 600mm tall, most Combi's with GFR are almost 1400mm tall which means mounting the boiler lower to get the flue out so you'd loss kitchen counter top and under counter space.

[@richardlewis5316]

I have posted the same. I would leave the combi installed and available to heat the radiators if needed and to heat the hot water as any combi does. A to A seems ideal as it can cool when needed and may cost less than gas but electricity is getting very expensive

[@nhojnhoj6767]

Have you made an update video?

[@nhojnhoj6767]

Any chance of an update?

[@gavinmackie1460]

Some more vids guys love your work

[@CheshireRing]

I don't question the honesty of this report, but I would better understand it if you told us what floor area the air to air system is heating and what the average temperatures have been for the two week period. Is the house occupied during the day? What rooms are heated? What is the target temperature in the bedrooms during the day and at night? I have an air to water system, Ecodan, that required 300 kWh of energy for a 170m² house, about 1800ft², during the same UK period, but I supplemented that periodically with about 50kWh of electric radiators to obtain faster response heating. Most of our underfloor heating in the reception rooms is at night on the Octopus Go off rate of 7.5p per kWh. Underfloor is fine but is slow to respond unless you have a hard floor (tiling, etc). So, I would like to understand the relative efficiency of the two types of systems on a 24/7 basis.

[@stevelympany3203]

Thanks. Interesting video. Not sure I agree with the hot water system and "diluting" it with cold water. If you have a well insulated tank, you lose little energy. If you mix it with cold water, you'll use less volume of hot water. Just energy balance. With Octopus I pay 7.5p /kwh. About the same as gas.

[@kadmow]

- indeed, swings and roundabouts, double the temperature, use half the water (losses through the insulation vs lower efficiency of a flash boiler) - storage hotwater tanks are probably best suited to being powered by electricity (or solar thermal) where there is a variable tariff - for offpeak heating overnight, saving money no the heating cycle - vs peak daytime rates (gas is rarely dual tariff)... We indeed live in a world where options abound, finding the absolute best system for everyone is not really possible, adequate is usually pretty good.

[@ecoterrorist1402]

get blanks in the fuse boards

[@dameonhill]

You're the first one to have noticed - I wondered how long it would be :)

[@Loopyengineeringco]

I worked it out because I'm sad. For the space heating: 190kWh electricity use total Would have been good to calculate the real cop. Let's assume it's 3.2. In reality, it should be higher. 10p/kWh gas rate 90% gas boiler efficiency equivalent 190*3.2=608kWh delivered energy for 15 days 608kWh/15=40.53kWh/day delivered 40.53*1.1=£44.58 gas boiler equivalent kWh usage adjusted for 90% efficiency 44.58*0.1=£4.458/day So it would have cost around £4.458/day in gas, which is almost the same as the electricity cost. So if the cop is better than about 3.2, air-air will become cheaper.

[@Lewis_Standing]

Yup that's the same for A2W systems too

[@benjiro8793]

You also forgot, if they switched 100% to elec, they do not have the fixed monthly fees of the gas supplier anymore. People tend to forget that the more delivered forms of energy, the more extra costs you get with each extra system.

[@waqasahmed939]

@@benjiro8793 Some may forget, but some may see it as an acceptable charge for the time being My own journey does involve replacing all my piping, and my radiators :( I won't be getting a heat pump straight away. It is something I'd want eventually but it's an incremental thing

[@jasonrhl]

I nearly fell of my chair when they said the cost per day. I want to know how much a heat pump radiator heating would cost per day?

[@Chris-hy6jy]

Need to compare that against the same timeframe using gas to get a true comparison. Also something people need to be aware of when running A2A heat pumps is that as soon as it gets below zero and you start seeing multiple defrost cycles per day, that electricity usage will increase by quite some margin.

[@gsum1000]

Our 3.5 kW HPAC has just completed its first test. During the recent big freeze, our heat pump went into its defrost cycle on a couple of occasions each day. The cycle consumes 2kW for 15 mins so is not too expensive. To avoid any possibility of recycling cooled air, which will increase the number of defrost cycles, it's really important to ensure that the airflow around the heat pump is not impeded.

[@richardlewis5316]

@@gsum1000 I used to have an office of 48 terminals which made the room so hot!! We installed window coolers but they frosted up every 2 hours in the summer!!

[@ccemcoffingonzalez5304]

Daiken now do an air to air heating + hot water

[@nixonsmateruby1]

If I have to wear a fleece in the house then I would just by a skip full of tealights and some plant pots.

[@timfallon8226]

It just makes sense. Spend huge amounts of money installing a heat pump to avoid using gas so you can buy more expensive electricity where the electricity was made burning gas in a power station. Pure genius.

[@stevenfrazer46]

Wind alone will be 30% of uk electricity production by 2030, more than all fossil fuels, these things will be running for the next 20-25 years so I don't think that over simplified comment is really very relevant.

[@effervescence5664]

The heating may have gone down but without comparing it to the gas consumption over the same period for the hot water you're unable to gauge quids in or out.

[@RobFisherUK]

I kept my gas central heating so I'm able to compare. In one experiment I ran on consecutive days with similar cold weather around 0C, it cost £2.63 for 23kWh of gas vs. £1.62 for 4.6kWh of electricity. That was for 9 hours of heating just a large kitchen diner where I was working. The ability to focus better on specific rooms helps too, since I don't have TRVs on every radiator.

[@richardlewis5316]

For once a heat pump and water heater is shown as a perfect solution. Why then do people not do air to air heating/cooling, leave the existing combi and radiators in place for emergency use and for hot water? Minimal disruption and no big tank for hot water which is always a retrograde step

[@Lewis_Standing]

Air to air can do hot water in a tank too, see VRZ and VRF systems.

[@richardlewis5316]

@@Lewis_Standing My main concern is the cost of running any heat pump especially if its working most of the day. I have established that a heat pump will run at between 0.8kw per hour up to 7kw /hour so if my house needs 2 kw/hour this is 74pence per hour (UK fixed tariff) 16 hours a day will be about £11 per day or £355 per month. My current gas bill is £120 per moth for heating and hot water.

[@richardlewis5316]

@@zlmdragon. Dear Vicki, Thank you for your informative answer to my question about the hourly cost of running a heat pump. I think the 7kwh was based on the start up current. All I am trying to evaluate is the cost of a heat pump running - it doesn't matter what the output is as its the ongoing cost of it operating maybe 16 hours a day. If the heat pump uses about 1kwh this will mean 16kwh used in a day which at my current EDF price is about £6.00 per day which equates to about £180 per month . Where is my calculation going wrong?

[@richardlewis5316]

@@zlmdragon. Thanks for your reply. You miss the point!! All I want to know is how many Kw a heat pump uses when switched on. I do not want to compare it with the cost of gas or the amount of heat a heat pump produces. As I said previously - if a heat pump uses 1kw to run this is a fixed cost which will cost me 37pence per hour so for 24 hours 8.88 so for 30 days £266.

[@richardlewis5316]

@@zlmdragon. This is why I assume a usage of about 2kw for a normal winters day heating so this will be about 24kw per day which is about £9 per day ie 270 a month. My gas and electric are £120 per month total as it heats the house in about an hour so a heat pump is a non starter. Thanks for your information

[@frankwitten7881]

Erster.

[@Kallenator1988]

Both pumps total 191kWh for 14-15 days, jeez, is this a big and poorly insulated house?

[@gsum1000]

Doesn't sound excessive to me. If he installed house batteries and used the the Octopus Go rate of 7.5p, that comes to a mere £14.33 or £26.65 for the whole month for space heating. Even cheaper if he had solar panels.

[@griffithsheating]

13kwh a day that's just over a cubic meter of gas. So assuming a cop of about 3 you're not that far off or beating a gas boiler. My weather comp'd combi will burn about 3 cubic meters a day to keep the house comfy but that's hot water also - so 33kwh.

[@wobby1516]

Don’t follow this chap’s analogy, heating water to cool it down is energy wasted? No it’s not wasted because if one has lower temperature water then one needs to draw more of it from the tank, that means the same energy used. If one has a larger storage of hotter water it goes a lot further and the only difference is the energy losses through the wall of the tank.. in our case it’s not that much but more to the point it’s in a cupboard that is used to air our clothes, that small heat loss is also inside our house.

[@BenIsInSweden]

There's about a 20% difference in heat loss between 50C and 60C stored in a cylinder due to the greater difference between the water temp and the surrounding area. So unless you're using all the tank and at a rate faster than it can be heated, you're better off making use of more water at the lower temperature. Because during the time you're not using it you're wasting extra energy on keeping it at 60C.

[@richardperry5538]

It's 2am and it's below freezing outside, I've cranked the heating up to 48 on the heat pump in the cupboard and the bloody thing is screaming it's nuts off outside keeping the neighbours up no doubt, and still this house is freezing. These things are a total waste of money, can't believe the government are pushing these things.

[@markramsay6399]

Costs aside - our heat pump is keeping the whole house at 20C and water at 55 (without any heating element). So if installed correctly (where the "install" is the whole system, not just the heat pump) then I think they work. Now with costs - I think our system is costing us £10 a day at the moment (!) based on 10-15 December 2022 (freeeeeeeezing). Then again, spring and summer it costs pence to heat a whole tank of water.

[@Lewis_Standing]

Sounds like you need larger emitters pipes or heat pump.

[@nhojnhoj6767]

No update? I suspect if the claims made about heat pumps were true there would have been an update crowing about it.

[@singlendhot8628]

Say what you want about the efficiency, the look of the residence has been transformed to 3rd world country spec with those external pipe runs and units.

[@Lewis_Standing]

It really hasn't

[@mikew4122]

The way you take your time to explain the details is what I love the most about your videos 😍😍❤️ . You are missing out = *Promo sm* !