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Why are Octopus flogging AWHP exactly?

Posted: Tue Nov 15, 2022 12:40 pm
by Mr Gus
Missing out on the ability to control cool, dry air & heat to deal with all season energy demands?

I rang up, that's what is being flogged as Daikin models (4 sizes i understand)

So, still likely to endure summer power stress via all the fans on in summer moving hot air around inefficiently. ..compared to a reversible heat pump.
Still likely to have the octopus units hooked up to under the window radiators peeing heat to the outside, not core room inner walls.

Just replacements for "whole house" heating & nothing inbetween ...how poxy! ..tis at a time when we ought be looking at moisture control & not heating empty rooms beyond a certain point.

The lad I spoke to on their dedicated ashp line didnt know what COP was, but was able to trot out the line between 3-4 times the energy for the same price, ..ouch.

Not enough clout as a company to take on govt & get proper useful change, merely a swap out for something a bit less pish I guess.
Aimed primarily at the gas boiler market.

Re: Why are Octopus flogging AWHP exactly?

Posted: Tue Nov 15, 2022 1:21 pm
by Oldgreybeard
Daikins are usually reversible. I'm pretty sure all ASHP are, as they need to reverse in order to defrost the evaporator. There is an issue with any MCS installed ASHP taking advantage of any government subsidy, though, in that the government insist that the cooling function be disabled.

I use our ASHP for cooling in hot weather. Works a treat, cools the floor down, usually to around 18°C, and that seems to be very effective at keeping the ground floor cool.

Re: Why are Octopus flogging AWHP exactly?

Posted: Tue Nov 15, 2022 1:30 pm
by Mr Gus
Understood, & I don't have a problem with diakin as a brand.
By reverse, I mean to the room (beyond defrost cycling) useful cooling more in line with modern living & the climate ambiguities,, & dangerously hot summer heat, be it a heat island or merely in direct sun.

We are not going to achieve much room cooling via water filled radiators on a hot summers day right !? (I'd love to be wrong about that mind you)

A real COP out one *might* say.

Re: Why are Octopus flogging AWHP exactly?

Posted: Tue Nov 15, 2022 1:39 pm
by Oldgreybeard
Mr Gus wrote: Tue Nov 15, 2022 1:30 pm Understood, & I don't have a problem with diakin as a brand.
By reverse, I mean to the room (beyond defrost cycling) useful cooling more in line with modern living & the climate ambiguities,, & dangerously hot summer heat, be it a heat island or merely in direct sun.

We are not going to achieve much room cooling via water filled radiators on a hot summers day right !? (I'd love to be wrong about that mind you)

A real COP out one *might* say.
I'm pretty close to 100% sure they will all run backwards and cool the house, on ours there are two dry contact connections for switches, one is the on/off switch the other is the heat/cool switch. I'd be surprised if Daikins are any different.

Cooling with radiators doesn't work very well unless the radiator pipework is changed. Most modern radiators have the flow and return at the bottom, and rely on the natural tendency for the hotter incoming water to rise to make sure the whole radiator is at even temperature. If you make the flow cold then it just shoots across the bottom of the radiator and out the return. The only way to get the whole radiator to be cool is to re-jig the pipes like old fashioned radiators and run the flow to the top.

Need to watch out for condensation, too, the flow temperature needs to be below the local dew point. This is much easier with UFH, as the water can be a fair bit colder and still have the floor surface above the dew point (as long as the short bits of exposed pipe are well-insulated).

Re: Why are Octopus flogging AWHP exactly?

Posted: Tue Nov 15, 2022 2:02 pm
by Mr Gus
Yup, exactly because of that! (nice context OGB) ..ergo restrictive & ill thought / under-utilising expensive kit, like buying a pint & finding you actually only get to drink half!