Ämne: Air to air heat pump: what to choose and consumption

[mcbota]

Hello!
 Happy blessed Christmas to all of you!
 I am from Romania, having a house where I have installed underfloor electric heating. The house is not yet finished , but I live there; only the exterior is  not painted ( I have  10 cm of polystyrene insulation over a 38 cm brick wall); the electric underfloor heating system works good enough, but I think with not enough heat in the rooms to heat the walls substantial and so keep the warm for a long period. I compare this system with my fireplace which I have in living room and I can see that the walls there keep the heat much better being heated with woods. I have read about air to air heat pump efficiency, and I am thinking  at this system. The house is about 160 sqm on 2 floors, almost equal divided. Please tell me if this system can be much cheaper than the one that I have? Which is the best solution for such a system to choose and  please tell me if you consider is a good choice and is worthy to make an upgrade to my heating system! What consumption can have at such an air to air heat pump for my house considering that the average outside temperature during the winter is around - 5 degrees Celsius!
  Thanks for answering and me
   All the best,

[Carl N]

It is usully to assume that an air/air heat pump needs less than half as much energy as direct electricity, maybe one third if the climate and the house plan is beneficial. It can be combined with electric floor heating as comfort heating, but more comfort will of course cost a little more.

[mcbota]

What I am not sure it is the fact of running cost and especially because of the house which has 2 floors. Do I need two small air to air heat pumps or one with 2 indoor units? What kind of heat I will feel: radiant heat . or just warm the air or also the objects? Has anyone an example of consumption at different outside temperature and indoor , for a house?
P.S
  Sorry for so many questions and sorry because I dont know swedish language

[TUCSONOR]

A bit warmer climate were you lieve. http://www.yr.no/place/Romania/Bucuresti/Bucharest~683506/statistics.html
With "only" 10 cm insulation, 160 m2 and -5 ºC you are pretty close to the need for heat as scandinavian standard insulated house. How is you window? Modern well insulated? how much insulation in the roof?
I pressume you house will need approx 200W/ ºC difference in/out. So , when having -5 ºC and 22 ºC, you are in need of 4.4kW, minus the heat from light, fridge etc.
If you got a pretty open house, one pump like MB FD25 VABH in first floor would be enough. But for improved comfort you could buy two smaller pumps, for instance cheap selfmountig split on/off Zibro pumps. www.zibro.com

[mcbota]

Thanks Tucsonor for the answers!
  The windows are triple glazed and the roof is a flat one with 10 cm insulation of polystyrene high density! My options are the same as yours but I am not sure if the performance/quality of Zimbro are good enough. Can you estimate a consumption for my house at 22degrees inside and lets say -5 outside.?

[TUCSONOR]

Thanks Tucsonor for the answers!
  The windows are triple glazed and the roof is a flat one with 10 cm insulation of polystyrene high density! My options are the same as yours but I am not sure if the performance/quality of Zimbro are good enough. Can you estimate a consumption for my house at 22degrees inside and lets say -5 outside.?

If my estimate is correct for your house (Never seen it ) you are in need of 5.4kW at -5 ºC. An average heatpump got approx a COP round 2.5 at -5, so your consumption would then be 5,4/2,5= 2,2kW.
Two Zibro SC1332 would give you the heat needed.
If you are a "handy man", you can easy tweak the cheap pumps performance so they became better, as for instance this norwegian guy have done: http://www.byggebolig.no/index.php/topic,34566.0.html

[mcbota]

The house is not so opened; I have tried to attach a picture but is bigger than 400 kb; however if this or around this will be the consumption, will be very nice. I will look better at that Zibro SC 1332 and see if is good enough and I will manage to buy two from Sweden or Norway, at a good price, because here are not very popular.

[mcbota]

What I dont know exactly is why on some details is written that Zibro is air conditioning and on other that it is heat pump? ( and this is available for other brands too) Here are the attachments of my 2 floors house! Do you think is enough one or do I need two heat pumps to be efficient?

[styrman]

Hi

I would believe that 2 completely separate units will turn out to be cheaper than 1 with two indoor uni
Check this out: http://www.comfortableclimates.co.uk/

I would also suggest extra insulation to the roof....
Maybe extra 20cm with cellulosa fiber 

Good luck

Robert

[mcbota]

Because I have a flat roof and I have already made an 10 cm insulation with polystyrene high density and put the insulation against water, I was thinking to make an extra insulation of the roof but the only possibility is to make on the inside part of the roof, in the rooms. So I am still thinking to the best solution, to not make too many changes and disturb the paint and everything  that is OK in the rooms. Thanks for the advices and for the link, Robert! I saw also MB FD 25 VABH and MB FD 25 VA, the first being the nordic option and the second saying that is only an air conditioning. Which are the difference and performance, between such products, generally speaking?

[mcbota]

http://www.eclimatizare.ro/catalog/split-de-perete-140029
From this products , available in Romania, do you consider that any of its are good as performance and quality for heating my house with a confortable temperature. running costs?

[TUCSONOR]

http://www.eclimatizare.ro/catalog/split-de-perete-140029
From this products , available in Romania, do you consider that any of its are good as performance and quality for heating my house with a confortable temperature. running costs?

All of them will do. Out of the prices, I would recommend getting two of these: http://www.eclimatizare.ro/cumpara/sistem-mitsubishi-msz-fd-25va-muz-fd-25-va-1261451 instead of cheaper ZIBRO that do not have the electronic expantion valve. Note, the cheaper MB pumps then the model FD25 might have capilar expation valve, so no better then the ZIBRO. You will be very happy with the FD25, and I believe it will give you good payback as you probebly have many days with between 0 to 10 ºC were you need heating, and the FD25 have very good COP in that range.



 

[mcbota]

I will appreciate you forever if you said that just one is enough!!!!! I understand that I need two, to have the best performance. Is there any difference between this one and the nordic FD 25 VABH? Do you think that two of these will be the best solution and best effciency? Many thanks for all your and advices!

[TUCSONOR]

I will appreciate you forever if you said that just one is enough!!!!! I understand that I need two, to have the best performance. Is there any difference between this one and the nordic FD 25 VABH? Do you think that two of these will be the best solution and best effciency? Many thanks for all your and advices!

You should manage with one, but for the comfort two is recommended. There is long discussions on this forum for what is the differences. The VABH modell have better defrost (more secure defrost) then the VA, and higher output on lover temperatures then -5.
If I were you I would installed one FD25VA in the first floor, and seen what happened the firts winter. The payback for one more will be some better comfort, and very little in the total cost as I believe one pump will cover 80% of your need.
Use the search on the forum, there is a lot about how to improve the FDVA25 for defrost if you experience build up of ice. Good luck.

[mcbota]

Where I can find the exact covered surface sqm for heating, for MB FD 25 VA , because some as polarpumpen, gives up to 160 and others give only 35 sqm?  Thanks !

[TUCSONOR]

Where I can find the exact covered surface sqm for heating, for MB FD 25 VA , because some as polarpumpen, gives up to 160 and others give only 35 sqm?  Thanks !

It is the heat lost due to low outside temp that is of interrest, not the sqm. A non insulatet room of 60sqm, can need more energy then a house of 180sqm. One MBFD25VA will do the work in your house down to -5, as you also have ligth, TV or other electric equipment that give heat.

[mcbota]

My fear is not about  efficiency of the system because of the poor insulation but because of the fact that the system cannot push the hot air and distribute all over the spaces that I need to be heated. From this point of view are them efficiently? In my case , I want to install it on an opened llobby( hall), which communicate with ground level and first floor and frm there make the distribution of the air!

[TUCSONOR]

I think you will do fine with one in the lobby. Keep doors open so the air can move around.
However, if you find this is good enough after one year, buy one more and install in second floor.

[mcbota]

Here in Romania  isnt imported the nordic product for FD 25, so the man from a shop presented me this product:
http://www.celsiusair.co.uk/equipment/mitsubishi/05/pdfs/product/mseries/MSC-GA-VB~MSH-GA-VB%20HP%20PI%20Sheet.pdf
  The GA 60 VB he said that will be almost enough for what I need. What do you think  about this? Is any problem because isnt an inverter product? It is worthy to make the investement in it or to wait and see how can I take the FD 25 VABH? The price is much lower, almost half from FD 25 VA?
   Thanks!

[TUCSONOR]

It will do, but is not as efficient as an inverter. (Look at the COP, 2.9)
But for half the price you will need many years with an inverter to gain the extra investment (4-5 years perhaps)
What is more conserned, having a on/of pump with that capasity I would be a bit conserned about the temperatur fluctation due to the high output that for a while is not present, then putting out 5-6 kW again.
This pump will cope for all you heat needed. An inverter model would give some more comfort as more even temperature output from the indoor unit. For instanse, I got an inverter with almost same compressor capasity, now with +1 outside it heat the hole house and the basement with continous 800W, in stead og intermittent running 0W-2200W.
Summary?: It will do, but for comfort it will not do.

[mcbota]

 Thanks for clarifying the problems. To make a short resume: the price for FD 25 model is about 1000 euros and for this GA 60 model is around 750 euros. It is more important the power or the COP, in my case, to have an efficient system for almost the entire house? The guy from the shop told me that this non inverter, blows the air more warmly than inverter so will be useful in my case considering that I want to put the system in a hall and circulate the warm air all over the house.

[TUCSONOR]

Go for the GA60. Good price, enough power to cover the coldest period, and when installed in the hall long way from were you normally stay most of the time, the temperature will even out so you probebly will not notice any temperature move up or down any were else but close to the pump indoor unit.   

[mcbota]

Thanks for all your advices. I know that I have just a small amount of money and I  have to take the best decision to not waste the money useless. So I am still thinking, to Bosch EHP 6 A A, at Toshiba  ras 10 PVAP, Panasonic HE9LKE and other very competitive. Till I will take the best decision, which are the best online shops in Sweden where to search  for good prices? ( I know polarpumpen only)?

[TUCSONOR]

Thanks for all your advices. I know that I have just a small amount of money and I  have to take the best decision to not waste the money useless. So I am still thinking, to Bosch EHP 6 A A, at Toshiba  ras 10 PVAP, Panasonic HE9LKE and other very competitive. Till I will take the best decision, which are the best online shops in Sweden where to search  for good prices? ( I know polarpumpen only)?

I'm norwegian, so here some swedes have to jump in to fill out for were to search. Remember, getting a non quick connect pump requier that you have someone vacuuming the system when mounting. Perhaps best is to get a pump from the local shop.

[mcbota]

 I understand what you say but the problem maybe can be solved by searching someone to mount the heat pump. I am searching in Nordic countries because I saw are very popular in your area and are better products.
  Thanks, Tucsonor

[styrman]

Thanks for all your advices. I know that I have just a small amount of money and I  have to take the best decision to not waste the money useless. So I am still thinking, to Bosch EHP 6 A A, at Toshiba  ras 10 PVAP, Panasonic HE9LKE and other very competitive. Till I will take the best decision, which are the best online shops in Sweden where to search  for good prices? ( I know polarpumpen only)?

Hm... have a look around and consider http://www.comfortableclimates.co.uk/

That's where we got our Mitsubishi.... Not a NORDIC modell with bottom plate heating but it has worked to -15, -20 ºC
And there price difference was not neglectable...
They delivered the pump at the door... and the mail contact and support was
very professional....

If I still lived in Sweden I would go fo a domestic supplier having all guarantees and installation included in the final price.... but in your case maybe the UK solution is worth considering. Just look for equivalent modells that you find in all adds on this home page.... check the specs... last letter may differ as that's what they claim is the NORDIC conversion with bottom plate heating etc....
But then again... there's a lot of heating cable and aluminum tape( sheet ) that can be bought for 300-500Euro 

Possibly some modells have diffrent software that regulates the defrost cycles...
But I can't tell as I don't know that.
Our pumps works in a climate just as rough as the Swedish one so... 

And I would definitely go for an Inverter....maybe little bit more epensive but more comfortable.... at 5 ºC our Mitsubishi was giving off pleasant heat using 264W/h
Look at lowest consuption ( a lower value will prevent the pump to stop frequently )

Google around nd check out some tests.... COP @ +7 ºC is not as interesting as
the output and COP @ -7

As TUSCONOR mentioned.... buy 1 , see how it works... save up for another one and get 1 more

Hope you find a good solution

Happy New Year

Robert

[rocas]

Buy a machine from a local installer. Then you get when the machine needs service.

[mcbota]

I would like to buy from here, from Romania, such a good product considering that I will have all the benefits such as installation, services and other stuff. But considering the diversity of the products and some big or small differences between the heat pumps imported to Romania and those from western and nordic countries, I am wondering what is  more important. For sure I will look to the COP obtained at lower temperature because for this reason, to heat during the winter days, I will buy it. Thanks for advicing me to look at a small power consumption. I will search and with your , I hope that I will find the best solution regarding needs/quality/price.
   I wish you all to have a better year, regarding health, spiritual, wealth and whatever God want to give us!