Is it worth it?

[Wil]

20 hours ago, CotswoldDoItUpper said:

Ok so it’s looking like ASHP is going to be the way forward. The only thing now is timing.

I guess that prices will keep falling over the winter and the cheapest time to install will be jan/feb next year. Just before the RHI runs out. 
 

Has anyone heard of an mcs installer that can ‘sign off’ a Diy installed system to get the RHI payments? It doesn’t seem to be overly complicated, just time consuming, to run and lag the required pipes? Am I missing something again?

That would be nice, if you find one, let me know. MCS requires some fairly stringent (but not complex) design which the company would have to take responsibility for you having done. I've found so far that even submitting all the paperwork myself and having a friendly MCS number to use, it's an absolute minefield for warranties etc.

[SteamyTea]

21 hours ago, SimonD said:

I simply do not know where to begin commenting on that white paper

Glad you read it, saves me bothering.

[CotswoldDoItUpper]

@Wil even if it’s just the basics of securing the unit down and running pipes to the right places. The really low skill stuff that there is no point paying an expensive contractor to do. I’ll see what I can find!

[Dave Jones]

On 27/07/2021 at 19:14, CotswoldDoItUpper said:

Ok so it’s looking like ASHP is going to be the way forward. The only thing now is timing.

I guess that prices will keep falling over the winter and the cheapest time to install will be jan/feb next year. Just before the RHI runs out. 
 

Has anyone heard of an mcs installer that can ‘sign off’ a Diy installed system to get the RHI payments? It doesn’t seem to be overly complicated, just time consuming, to run and lag the required pipes? Am I missing something again?

 

id really have a think about that. It will be a LOT cheaper to run oil. If you have an old house without massive insulation then you will have an uphill battle. the tepid water from a heatpump needs massive radiators (3 or 4 times the size of normal ones) unless you fig up the floor and put in underfloor. 

 

You will go from limitless hotwater to limited, which may be ok for a small househo9ld but if you have kids etc its like going back to the stone age.

[IanR]

25 minutes ago, Dave Jones said:

 It will be a LOT cheaper to run oil.

 

No it won't.
Heating Oil is 42p per litre and 10kWh per litre so at 90% efficiency of an Oil Boiler = 4.67p per kWh
A heat pump has only got to get to an average COP 3 to be cheaper - that's pretty easy.

 

The OP is actually using LPG, which is more expensive than Oil.

 

31 minutes ago, Dave Jones said:

You will go from limitless hotwater to limited, which may be ok for a small househo9ld but if you have kids etc its like going back to the stone age.

 

That's rubbish. I've never run short of hot water with a family of 5 and a 12kW ASHP.  DWH efficiency is unrelated to insulation and air-tightness, so the same for everyone.

[PeterW]

2 hours ago, Dave Jones said:

the tepid water from a heatpump needs massive radiators (3 or 4 times the size of normal ones)

Factually incorrect. 
 

A radiator size is related to two factors - heat loss and delta-T.

 

Heat loss is the same irrespective of the radiator size, as it relates to room size, shape, insulation levels and windows.
 

Delta-T is the difference between the water temperature and the desired room temperature. All new radiators under BS-EN 442 are sized at dT50°C assuming the flow is 70°C and the desired room temperature is 20°C. 

 

Taking an example room heat loss of 885W (2720 BTU), this would require the following :

 

Using a flow temp of 70°C (std Gas/Oil) then the radiator would need to be something like a 500 x 1000 Type 11 Single Rad

 

Using a flow temperature of 47°C (ASHP) the   Correction Factor of 0.43 would require an equivalent output of 2058W  (6325 BTU) which would require a 500 x 1200 Type 22 Double.
 

That’s 200mm longer, and 25mm deeper than a single rad. Not 3 or 4 times the size. 

 

Let’s stick to facts and not conjecture and guesswork please. 

[SteamyTea]

2 hours ago, PeterW said:

 

Let’s stick to facts and not conjecture and guesswork please. 

It is just @Dave Jones trolling again.