New Central Heating system help with working out rad output

[zenculture1002]

I am in the middle of getting quotes for a new central heating system for my 2 bed 1st floor flat. I am thinking of putting in a Baxi duo-tec 28 he platinum, with a ADEY MAGNACLEAN PROFESSIONAL 22MM, because the boiler will have to be positioned in the front bedroom I am thinking of using a GRUNDFOS CONLIFT AUTO CONDENSATE PUMP to pump up into the roof space and across to the waste pipe. I would also like to use a Danfoss Randall TP5000 Si 5/2 Wireless Programmable Room Thermostat with RX-1 Radio Frequency Receiver. my first question will this combination cover my particular type of abode.

the 2nd part is to do with the rads I am looking at putting 5 rads fitted with with a heated towel rail for the bathroom all fitted with Drayton TRV4 Thermostatic Radiator Valves. I am thinking about putting in Aluminium rads because I have heard they tend to be more efficient, although alot more expensive, therefore I am trying to work out the btu/watts so that I can buy the correct rad size. As all the online btu calculators seem to come up with different totals is there any better way of calculating btu/watts.

Anyone who could point me in the right direction would truly be appreciated

[DEEARR2]

Your 5 rad system will be well covered by the configuration you mention.
As far as sizing the radiators, the use of a Mears calculator would be most accurate, this rotary disc takes into consideration all heat losses and gains that require to be allowed for in domestic premises.

Unfortunately I donn't have a Mears, perhaps another member of the forum may offer assistance with this.

[rosebery]

If you are getting quotes ask those you are asking to advise on your ideas and tell you if they are good or not and what their recommendations are for your system.

Cheers