what heat pump for cold winter?

[orientalmed]

Hy , thanks that I found this forum. I live in Romania and in my country very few heat punp exist. The prices are big and people do not know much about them.

MY SITUATION:

I live in an apartment with 2 small rooms about 18 m2 and 13m2 squared meters surface
I want to heat that apartment with one or two HP. My apartment is well isolated at windows and walls.

The main problem is that in my town the winter temperatures is usually about -10-15 Celsius and sometimes ( for about 2-3 weeks /winter the temperatures drop under -20 Celsius, even -25...
I have winter for about 5 month/year.


I know that Mitsu ZUBADAN is the most efficient HP, with the bigges COP at -25 Celsius.
But the price is HUGE for me. about 1700 EURO/unit. I cannot afford it.

I also know that Daikin Ururu sarara is a good unit working range starting at -20 ... and the price is..about 1100 euro/unit. Affordable..

My main concerns is about the COP ( or the efficiency) for the Ururu sarara at low temperature. I do not find what is the COP value for -10, or for -20, or for -25..
I do not want to pay for many KW/h..I just knw that he work at -20, but I do not know the Cop eficiency.
some advices please? or another equipment recommendation..

Dan

[chillerman2006]

Hi Dan

for your ambient, stick with a gas boiler & forget heat pump's

R's chillerman

[orientalmed]

Thank you , In my country the gas price is increased month by month.It is very expensive..Also to install an new gas unit in my apartment it is about 2000 euro. Very expensive.
My Brother have an gas unit in a similar apartment and the bill gas is big.
I know some people that claim that they are happy with the Zubadan air, water pump. and the expenses are cut by 40 %

[brunstar]

put in a 6kw Daikin unit, the min temperature is -15 but if it is that oversized it will be able to cope. A better option would be is to put in a 6kw multi and you could just use one indoor unit when it is mild and when it is colder you could use both which will keep you warm. if it is -20 outside i think a room temperature of 18 to 20 degrees will be nice.

[orientalmed]

vs.png
Based on a 2.7 kw need to worm my room, what from the two mitsubishi uits are suitable for me.

The firs seems to little undersized at low temperatures -5, -10 C outside, and the second seems to be over sized at normal temperatures +5, 0 C. Normaly my winter is about -10, someday -15 C or more.

What is your recommendation?
Thank you

[orientalmed]

Consider desired inside temperature about 21C.
Also I calculated that my room need about 2.5- 2.7 KW

[install monkey]

always go over as its better to oversize as having a 2.5kw unit running constantly trying to heat the room on the coldest day and having a compressor failure, as a 3.5 will reach setpoint quicker

[orientalmed]

Install monkey..
1) thank you for your answer
2) sorry for my poor english and understanding..Sincerely I do not understand your answer.
Maybe I understand corectly your answer: an 2,5 kw unit ( nominal ) is undersized for cold winter..and I must to go for the bigger one?
The smaller units will work hard and at maximum air flow to mantain the desired temp?

muz fd35 va , as in the following table?
Some math said that the bigger unit will be high costing over the normal temperatures..about 0-5C.

vs2.png