Відео

Thanks for all you do, Mario - love your explanations!

I have 8kw mono and my dt is set to 5 but it runs at around 2.2 , is there any problem ? I think my main pipes are undersized 14m long and 22mm (copper) :/

Zdravo Mario, opet ja. Moji 140 kvadrati su pokriveni sa 17 krugova u prosek po 70 metara po krug, podno je na 10cm. Koristim Panasonic Aquarea TCAP 9KW. Primetio sam da protokomeri ne mogu vise od 1.5 - 1.7 L/min. Ali to nije dovoljno, neke sobe su mi malo hladni 19C, a najtoplija sobe je neki 23.5C pri temperatura na polaz od 35C. Interesue me dali postoi mogucnost postoeca recirkulaciona pumpa da se zameni sa jaca, ili dali ima mogucnost seriski da rade dve pumpe. Ili pa najbolje resenje bi bilo puffer i dodatna pumpa?

I have around 4kw heat loss , the installer was pushing for a 10kw , and i ended up with 8kw heat pump , there is option for upper power limit , do you think it would be better to run it on 6 or 5kw?

If you ad more radiators instead of aditional buffer wont be better ? You can even run on lower flow temp after

Thanks for the great video. If you have time to check my comment (questions) below, I would be happy. Keep doing the great job!

Pojasnite kolika bi trebala biti temperaturna razlika (delta t) u samim radijatorima? Znači idealna temperatura na ulazu i na izlazu iz radijatora (balansiranje) Da li je to 3°C, 7°C ili možda 10°C? Uzimamo u obzir da se radi o toplotnoj pumpi vazduh-voda, gde je idealni delta t oko 5°C ili niži za efikasni rad toplotne pumpe.

Zdravo Mario, imam panasonic tcap 9kw, 140m2 podno bez pufer. Dali je ok da se pumpa gasi u prosek nakon 3 sati?

It is not only the system volume, it is the volume in combination with the temperature of the volume. If you have 300 litres at 10 degrees, it will not defrost your unit, or it will take a lot of time compared to 30 litres at 90 degrees for example. I run a 7KW Panasonic J series, The pump will use its 3 KW backup heater for a defrost cycle for 10 minuutes if the inlet water temperature is below 27 degrees. I have enough volume (about 80 litres) but the temperature is too low. On a humid day at around 2 degrees outside when the inlet temperature is arround 22 degrees, i can expect a defrost cycle every hour. That is 12 KW consumption on the backup heater alone in 24 hours! The house does stay warm, no problems there, however the COP drops like a rock. The hidden cost of running on low temperature.

Appreciate your videos. Very helpful. can i know the technical reason why heat pump output power drops when the flow temperature increases? I do know the efficiency drops as the input energy to the compressor will rise, but why would the output drop?

Another very important issue (as well difficult task....) is to combine the heating and cooling loads, so as to select the proper heat pump capacity, so as to avoid oversizing....In Mediterranean regions, cooling loads are the important and usually define heat pumps' selection, while other parameters like coincident factor in cooling use are challenging in the final decision....Selecting heat pump so as to cover cooling loads hides a risk to oversize in heating.....I suggest to prepare a video on this too....

Perfect explaining video! In fact, I opted for undersizing my heat pump! I put 16kw instead of 19kw... Let me explain, in Greece we use 0oC to calculate heat losses, but in my area 0 is happening 1-2 days/year, for 1-2 hours...so 99% of the time is > 5oC, and for the rest 1% the heat inertia of the house will Keep it warm enough so I don't have a problem. Indeed, 2 years now and the heat pump really hasn't reached its full power, ever!!! I don't suggest anyone doing it specially in more northern countries, but it proves how catastrophic oversizing is!!!

Excellent video, thank you. I think that after calculating heat losses in the software, it is advisable/essential to analyze the results to identify which elements have the highest heat losses. This helps to account for the imperfection of the initial data and improve insulation within a reasonable budget.

Another excellent video, just to clarify in the example I assume that the 250 m'" 2 house is the floor area only or is it the floor, ceiling and outside walls representing 0.24 W/m'2? though you right that a great many heat pump installers do not do the sums or mis understand the principals of low temperature heating and so totally oversize the heat pump, it is very common problem in the UK( but is getting better) are you having a similar problem in Croatia?

Excellent, thank you very much for that information.

Great presentation as always. Really to the point, from skillful guys. Congratulations ! Same story here in Greece....oversized heat pumps, selected from commercial companies or plumbers, using only rule of thumbs because "they know"....Even though nZEB regulation is really close for new buildings in Greece (according to the current legislation, low energy buildings are the only way for someone wants to build a new home in Greece, even though it is still not so energy efficient as nZEB)

Hello Mario, I’m in the UK, and all the things you outline in this video are true for the UK too, with building regulations, insulation requirements, SAP certificates etc. Please keep producing the content, it is very useful and detailed. People are still being given lots of misinformation about heat pumps.

Very clear and well explained.

Clear and simple. Just right.

It is worth to mention that Panasonic Heat Pump can use water from domestic hot water tank ( ili PTV na hrvatskom ) for defrosting.. There you have more than enough hot water to do defrost with less interference on heating. Anyway - its always good to have something form you Mario as we learning that way. thanks..

Zdravo Mario, imam tcap 9kw i radi samo podno i sanitarni boljer bez pufer. Reci mi koji radni tlak treba da pokazue onaj manometar koji e na unitrasna edinica. Kod.mene e 1-1.5 bari.

Thank you for this lesson, it is very important and useful information. I learned a lot of new things.

Thank you for this video! Really informative, good job. 👏👏

If a buffer is installed due to needing more head pressure than is capable from the heat pumps own pump, from what I understand the flow rate should be balanced in and out of the buffer to avoid water mixing. Since the after buffer pump is set to a constant flow, should the heat pumps own pump also be set to a constant flow? Or should it be allowed to modulate? Thanks

Pozdrav majstor Mario. Upravo sam uradio sustav bez puffera, uglavno sam pratio vashi kanal i vashi upute. Rec je o 9kw Panasonic TCAP, na 140 m2 sa sanitarni spremnik. Kuca ima sendvic fasada, dva bloka i izmedu tervol. Cevi za podno grijanje su na 10cm. Kuca ima malo starija pvc stolarija mozda od pred 15 godina, obicni termopan staklo i Rehau profil. Plafon nije izolovan, a ispod cev je 5 cm stirodur. Zapravo grijanje vozim po kompenzaciona krivulja. Dok van je bilo neki 11 stupnjeva, ishao sam sa voda u polaz 35, kod kuci je bilo pretoplo, ambientalna temperatura isla i do 26 stepena. Ali kada je doshlo nula, ambientalna temperatura ne mogu da povecam vise od 24.5 stepena, a delovi gde su vanski zidove su prilicno hladni i idu do 21 stupanj, a ispod prozora idu i do 19. Kada prolazis pored vanjske zidove i nje bas ugodno, oseca se varijacija na temperatura i hladni valove. Uglavno rad kompresora je izmedzu 32HZ a jedan put je bio 53Hz. Potrosnja varira od 20 kwh u topli dani, a kada je hladno i do 40kwh, voda grejem u opseg od 32 - 40, a temperatura poda je 26-28 stupnjevi. Recite mi po vase iskustvo, dali ovaa potrosnje od 20-40 kwh je razumna a josh nisu negativni temperaturi. I dali ove izlazne parametri koji sam nabrojao su slabi ili su ok. Dali mislite da bi mogao nekako da poboljsam performans na celi sustav. Pozdrav

Your videos are awesome BTW! On a standard uk system where bedrooms have TRVs or a new build where the upstairs is zoned (and we can’t guarantee customers won’t turn them off) Some installers therefore install a buffer to protect the ODU. Is an alternative to disregard the zoned volume from the system volume calculation and potentially install a volumiser (if required)? That way the defrost and start/hour are met by the section of the system that remains open and if the upstairs rads/zone is open the system gains additional volume and reduces cycles/hour. Is there still an issue regarding the output of the unit if the heat load is potentially halved? Or if minimum system volumes are met is this minimised?

Panasonic is known for "under-reporting" electricity consumption for up to 15%. And who knows what is it "reporting" on heat production side. Without buffer tank (you can easily calculate how much heat has been produced) and without external electricity meter all those COP from heat-pump computer are nonsence. Only heat pumps on the market who report consomtion and produced heat in 5% margin of error are Junkers/Bosch, all others ar reporting COP with up to 20% error.

Pozdrav, Mario, planiram da ugradim LG monoblok 5kw u stan od 60kvm, imam 4 radijatora 600x1200, da li mi je potreban bafer, ja ga ne bih postavljao iz estetskih razloga?

So how do you calculate system volume?

Ako zelimo da dodamo vise vode sistemu u vidu volumizera da li ga dodajemo na hladni ili topli vod?

Mine froze solid last winter so had boiler installed again . Avoid heat pumps !

Thanks for these videos. 5 degrees is fine, but the lower the better. (I guess at some point you are spending money to run pumps, etc). I think on hydronic in floor heating its easier to hit high flow rates. On my hydronic heat pump, with 200m^2 of 1/2" Pex in concrete in floor heating, there is a lot of thermal mass, and upon starting the heat pump, the delta T is like 1C. It's a 3T 35,000BTU water to water, COP is about 4 or even 5. Circ temp is 34C.

I used to commission industrial units and it was always considered to be poor practice to have two or more pumps on the same circuit without a low loss header or similar and also some form or measuring device (FMD) such a device takes the guesswork out of the equation, heat pumps are a great invention but it is usually it is the installation that lets the technology down. Great vid as is said great food for thought.

Great video! I have a Daikin 16kw Heat Pump, with 11 fan coils and 3 towel radiators in the bathrooms. Never got a heat flow problem, no buffer. But when I installed it (made the heat loss study myself as a mechanical engineer, but I had no experience with HVAC at all) the shop owner where I bought the HP advised to use Φ25 pipes for the larger fan coils, because in cooling we need unobstructed flow. So that's how we went, Φ25 for the larger fan coils, Φ22 for the medium, Φ18 for the smaller ones. So, with 11 fan coils and so many meters of good diameter pipes, I have enough liters in the system (even with the 3 radiators out, to avoid condensation) the heat pump works perfectly, it modulates between 15 and 30 liters/hr as far as I have seen, with miminal start/stops. I don't have buffer and no 2way or bypass valves on any fan coil (just the fan motor modulates when they reach the set temperature). I am pretty satisfied.

How the heat pump manage to make hot water for shower ? Is switching from cooling to heating automatically ?

Hello. Very interesting calculation. I have a Vaillant arotherm plus Hp, and I simulated these calculation on Vaillant figures. Flow rate is fixed (860l/h), DT in 5 most of the time, and is 2 or 3 only when warmer outside. I have some 135l system, no buffer, and I do not see cycling upto ~ 10C outside. Are these calculation maybe only for Panasonic HP?

Greetings from Uruguay. Your videos are very informative and with good technical background!

Mario, I think you made a mistake a 3:50. Temperature difference is 11°C, desired indoor temp. is still 21, so maximum outdoor temperature for modulation should be 10°C (21-11=10)... Am I correct? Pozdrav i hvala!

Pozdrav, može li kontakt?

I have a house in construction with aprox 154m2 of radiant floor (which is also prepared for cooling). The house is divided into two floors. I plan to use an heat pump for, heating, cooling and hot water. I have two questions, 1.how many kw would recommend for this house given it is well isolated and located in Portugal. And 2. would you run a the system in open loop? I don't mind heating or cooling the whole house at the same time since me and my girlfriend both work at home. Thanks in advance.

Very Clear Explanation. TKS

Hello How i contact you. Our house is 900 m2. i can't calculate heat pump. help me

Zdravo Mario, interesuje me koja ja razlika izmedzu trofazni i monofazni 9KW TCAP model.

High temperatures are no good for heat pumps. To obtain the highest SCOP and therefore get the full benefit of using a heat pump it needs to be run at low temperatures, typically no more than 35degC for UFH or 45degC for radiators. At these temperatures, R32 is far superior to R290, based on evidence from both research papers and the UK MCS test database. The MCS test results clearly show that R32 heat pumps are far more efficient than their directly equivalent R290 counterparts, for example the Mitsubishi R32 6kW model (PUZ-WM60VAA) has SCOP of 4.81 at 35degC, compared to the Mitsubishi R290 6kW model (PUZ-WZ60VAA - a much newer model) which has a SCOP of 4.39 at 35degC. If you look at the new "Cosy 6" R290 heat pump offering from Octopus, the MCS test result for SCOP is even worse at only 3.98 at 35degC, a surprisingly poor result.

Hi Thanks for sharing such informational video. I have a question.in the start you explained that coil surface should be 0.5 m2/KW to 1.5 minimum but in the calculation it is not used anywhere so how does it have an impact for heating the domestic hot water requirment. you used the formula m x sch x (tout-tin) for finding the energy.

Really important issue. It is true that the old approach still exists....the designer adds 15% as safety factor to calculated losses and sends the KW to the installer, who adds another 15% and sends it to heat pump provider who also adds some KW to round at the closer larger heat pump of his catalogue.....heat pumps are not cast-iron boilers with large thermal mass....

Super video.

great job, man!

Hvala imenjak za dobru prezentaciju!