I realise now that I was replying to an earlier message! I was replying  to your brain knot comment. Sorry! It's not surprising you didn’t understand what I was saying. Well done for making so much progress and getting the right wattage pump and 2 bigger radiators out of Octopus! 

@jancold I'm dying to know how they respond to that 45º request - it will also be interesting to hear about the spec they offer you. 

Please do tag me or add it here. 😁

@judith I hope it's ok but I think for the price it's not bad. And the comments here are reassuring. 

I will try to post the docs when I'm not so tired and overloaded with work. 

I now have a radiator schedule - total output 5353w [with 6kw Daikin + Daikin water tank 180 litres] Yes, I have a couple more upgrades. [🤫]

They've designed for 50º and are absolutely refusing to budge on that.

The bathroom is keeping the towel rail and I'm adding a small aluminium 'designer' radiator at 493w @ d30 - my expense. 

I think the rads now give me a bit of room for manoeuvre on the flow temps - what are your thoughts please? 

Why is the bedroom rad over twice what is required yet the lounge barely covers the heat loss.  I may be talking rubbish but logically doesn’t that say to keep your lounge at 21C your bedroom is going to be very hot unless you turn the rad off with a trv which defeats the purpose don't you just fit a smaller rad in the bedroom and you will need bigger in the lounge if you want to run at lower flow temps?

This is the reason they won’t lower the design flow temp as then the rads in the lounge won’t cover the heat loss.

Thats my interpretation hopefully someone else will come along and make more sense of it. 

@gary

You are absolutely correct! They won't lower the design temp because they want to keep costs low.

I had a discussion on Twitter with one of their head honchos the other night - he freely admitted that they tried to plot a path that keeps installs lower cost. 

The bedroom rad was upped because it's an office too but I agree about the living room it's a pain they're not bigger. 

Basically what they're doing is slot-ins - they don't want to do any pipe work - even though my pipes are visible/easy access in my cellar. 

Originally they were only going to change the two living room rads. The rest I've negotiated since. 

@gary I can’t help feeling that the surveyors have a phobia about fitting the minimum size emitter that might possibly provide enough heat (as long as the system has a design temperature of 50 degrees C) in any given room. Maybe they fear that if they even suggest a larger emitter, the customer will run shrieking from the room TOO BIG - TOO BIG!

When our surveyor sized the emitters, I expressed my feelings that I wanted the emitters to be fit for the task as well as fit the room! As it happened, most of the emitters are the same width and height as the ones they replaced but deeper which I felt was a minor loss of space. I reviewed the list when I received their suggestions and *‘shrunk’ one and enlarged another - the result is very satisfactory to us, and we like it warm!

*The shrinking of one was because I knew the room stayed warm by conduction from the hall and the adjacent room and I felt the emitter left insufficient room to access drawers in a dressing table.

Despite MCS guidelines, I feel there should be more communication between surveyors and the users-  a few minutes talk and explaining could save a lot of agro later! Regards, Toodles (Or was I just lucky?!)

hopefully the heat loss is less than calculated and the living room will be warm enough at lower flow temps not a lot else you can do you seem to have squeezed as much as possible out of them so kudos to you for that

@gary I agree. It's a lot better than it started out. I have been insistent throughout that 50º was passing the running & maintenance expense on to me.

I was miffed that it flies in the face of the entire theory of low flow, efficient heat pumps and I told them that. Repeatedly. 😁

But it has become a 'papal edict' from HQ I think.

The rads are a bit out of balance particularly those in the living room. However, it is a bungalow with all the rooms coming off a square central hall and hopefully leaving doors open & running a totally open loop system should allow me to level it out and run it at 40º at least. 🤞🏻

Posted by: @lucia

↑

@gary I agree. It's a lot better than it started out. I have been insistent throughout that 50º was passing the running & maintenance expense on to me.

I was miffed that it flies in the face of the entire theory of low flow, efficient heat pumps and I told them that. Repeatedly. 😁

But it has become a 'papal edict' from HQ I think.

The rads are a bit out of balance particularly those in the living room. However, it is a bungalow with all the rooms coming off a square central hall and hopefully leaving doors open & running a totally open loop system should allow me to level it out and run it at 40º at least. 🤞🏻

Overall you seem to have done as much as you can to get a good deal.  In fairness to Octopus they have decided on a broad methodology and they are sticking to it.  A minimum upgrade route compensated to some extent with tariffing has the merit that it gets the transition we need to make done at a price more people can afford.  It could be argued these the latest building regs take a similar approach by specifying a max design temperature for the flow (whatever the heat source) of 55C, not ideal from the point of view of a later heat pump retrofit, but not a disaster.

I guess one might argue for a subtle variation, namely that those emitters which are upgraded to meet the chosen design temp of 50 should be sized for 45 or even 40 thus paving the way for future improvement. However otherwise it's a valid design philosophy imho, certainly no less valid than the 'rip everything you can out and start again' approach taken by the grant chasing fraternity, that seems to make up the majority of the industry.

@jamespa 

I agree about their strategy. They're plotting a middle route. Their Cosy thingy is a step further along with that thinking. Heat Pump as plug-and-play gas boiler substitute. 

I couldn't afford anyone else and I think that's fairly representative of lots of potential customers. The problem however, is that most people won't want to go deep into it and thus will be left running 50º systems that will cost them in energy bills. Lets hope Mr Miliband starts to shift the weight off electricity tariffs and onto gas. 

Meanwhile, as someone pointed out in one of Mars' videos, this will then reach a level where it has grid impact. 

@lucia My efforts stalled as the Octo surveyor did not supply enough information for the tech designers. So they want to resurvey next week. In the meantime I was contacted by an installer who is doing a survey on Thursday. I am hoping that this guy has practical experience rather than the Octopus guy who came from a software background. If octo come through (though maybe they will decline if the installation does not suit their rigid criteria) then I will upgrade more radiators myself so I can run way cooler than 50C. The next hurdle is which tariff to go for in conjunction with a battery or solar or even an EV!! I will update next week.