Gas or ashp . both available, but which is cheaper to run?

[saveasteading]

I have been visiting in-laws. Their 2 bed bungalow has gas CH. The council have been along with money to spend and have fitted an ashp into the existing system. As far as i can see, they can use either the gas  or the ashp.

They don't really know what they've got or how it works, so neither do I.

 

I created some confusion in suggesting that it may be better value to continue burning gas, and ignore the ashp.

 

They also had insulation placed in the attic which is better value than the ashp.

The bungalow is 1960 ish, and is cavity wall with eps pellets.

 

Wondering what you clever lot think. Hunches are acceptable. Gas or ashp?

 

 

[SteamyTea]

6 hours ago, saveasteading said:

Hunches are acceptable

I suspect that gas is cheaper at the moment.

Just divide their electricity price by the gas price and see if the number would be acceptable as a CoP number i.e. 3+.

 

I wish the council down here would spend some money on my house.

[S2D2]

It depends which ASHP and tariff. I think at the new variable October rates it's around a cop of 3.6 needed to be cheaper, easily achieved by a well installed system and modern ASHP. Any time of use reductions to electricity rate likely to make it a no brainer if that works for them. 

[nod]

I think most will concede that gas will be cheaper to run than ASHP 

But in saying zig The local authority will cover the whole cost of ASHP 

Its a no brainer 

[Dave Jones]

7 hours ago, saveasteading said:

I have been visiting in-laws. Their 2 bed bungalow has gas CH. The council have been along with money to spend and have fitted an ashp into the existing system. As far as i can see, they can use either the gas  or the ashp.

They don't really know what they've got or how it works, so neither do I.

 

I created some confusion in suggesting that it may be better value to continue burning gas, and ignore the ashp.

 

They also had insulation placed in the attic which is better value than the ashp.

The bungalow is 1960 ish, and is cavity wall with eps pellets.

 

Wondering what you clever lot think. Hunches are acceptable. Gas or ashp?

 

 

 

do the heat loss calcs. then do the math!

[JohnMo]

Get the manual out, if a proper hybrid install there will be an algorithm in the controller.  You basically input the tariff info for gas and electric and it sorts our when to run, based on the cheapest for the end user.

 

Combi boiler?

[ProDave]

Are you saying they have installed an ASHP and left the old gas boiler?  or have installed a proper hybrid gas boiler / ASHP (first i have heard if that is the case)

 

Do they use gas for anything else e.g. cooker?  If not they could have the gas disconnected to save the standing charge if the ASHP proved adequate.

[JohnMo]

38 minutes ago, ProDave said:

Are you saying they have installed an ASHP and left the old gas boiler?  or have installed a proper hybrid gas boiler / ASHP (first i have heard if that is the case)

I know Daikin do an ASHP specifically designed to be installed with an existing combi boiler. Boiler does DHW and heating. But heating can be done by ASHP only or mix of gas and ASHP or gas only depending on energy cost and CoP of ASHP.

 

There are lots of advantages to a hybrid system, basically very little plumbing or radiator changes. System runs on weather compensation, it's only when temps get close to zero that the boiler kicks in. You don't need a cylinder, which can be a big issue in a small property and ASHP can be tiny.

[saveasteading]

1 hour ago, ProDave said:

Left the old gas boiler?  

As far as i know, this is the case. The residents don't seem to know anything about it really. So i've no idea how it switches over.

All they know is that the ashp option takes a long time to heat up....makes sense with the existing rads retained.

 

Cooker is electric.  Next time im there i will try to poke around a bit more, if permitted.