ASHP or oil?

[slidersx200]

Our NI based build will be heated by a LPG combi boiler, feeding into an UVC, supplemented by the PV driven immersion heater.

 

We are choosing LPG over oil for a few reasons:

 

*Grid gas is due to pass our house in the next 2-5 years

*Calor supply the tank and concrete base

*They supply 1500 litres of LPG to new customers

*The LPG boiler can be converted to natural gas cheaply

*Gas boilers are quieter and odourless (ours will be in the house)

*Gas boilers can modulate their output

*You can leave Calor without penalty if you change fuel source (grid gas being acceptable)

*Lower capital costs

*Much lower likelihood of theft with gas

 

My main reason for moving away from an ASHP was that it is most efficient in the summer when heating is needed less and PV will be producing most, and least efficient in the depths of winter when PV output will also be lower. 

Edited August 15, 2016 by slidersx200
Additional bullet point

[DeeJunFan]

38 minutes ago, slidersx200 said:

 

*You can leave Calor without penalty if you change fuel source (grid gas being acceptable)

 

 

This is our main reason for not considering Gas.  There is no chance of mains gas ever coming to our site.  

 

And if you change from Gas to Oil of ASHP then you have to pay the full costs to get the tank de-commissioned and removed.  I'm pretty sure they would be very punishing on the costs for this.

[ProDave]

1 hour ago, Declan52 said:

Can he not say he is going all electric but put in all what's needed for oil and install it once it's passed.

That's what he wants to talk to me about.

 

I am thinking of persuading him that a GSHP is a lot of work for little gain, and a monoblock ASHP would be a "better" option and easier to swap later on for an outside oil fired boiler.

 

Then when he's signed off I could buy the hardly used ASHP from him 


 

[DeeJunFan]

5 minutes ago, ProDave said:

 

Then when he's signed ff I could buy the hardly used ASHP from him 

 

 

Evil Genius

[slidersx200]

53 minutes ago, DeeJunFan said:

 

This is our main reason for not considering Gas.  There is no chance of mains gas ever coming to our site.  

 

And if you change from Gas to Oil of ASHP then you have to pay the full costs to get the tank de-commissioned and removed.  I'm pretty sure they would be very punishing on the costs for this.

The Calor rep told me that you can change to oil, electric, grid gas or biomass etc without penalty at any time and you can change LPG supplier after 2 years.

[DeeJunFan]

2 minutes ago, slidersx200 said:

The Calor rep told me that you can change to oil, electric, grid gas or biomass etc without penalty at any time and you can change LPG supplier after 2 years.

 

They told my brother the same thing, and i was very suspicious so i read the terms and conditions and they state that you can switch supplier without any penalty but if you move away from gas they will remove the tank as it remains their property and you will be charged the full costs to de-commission and remove the tank.

[Declan52]

1 hour ago, ProDave said:

That's what he wants to talk to me about.

 

I am thinking of persuading him that a GSHP is a lot of work for little gain, and a monoblock ASHP would be a "better" option and easier to swap later on for an outside oil fired boiler.

 

Then when he's signed off I could buy the hardly used ASHP from him 


 

There's always a way round it. 

If his house is not built to pretty close to pH standard would a gshp even touch the sides of meeting his heat demand. Considering the very large outlay to start with it would be a non runner for me.

Could you not combine the two, ashp for low constant heat and an oil system to provide the dhw. Or is that too complicated a system to install.

Or even an ashp with a stove and back boiler to give the large tank a boost from time to time.

Edited August 15, 2016 by Declan52

[joe90]

I considered having LPG to top up warm water from the ASHP to give hot DHW as like you we will have LPG for cooking. But doing the numbers I reckon direct electric ( using e7 as well ) works out better.

[DeeJunFan]

8 minutes ago, joe90 said:

I considered having LPG to top up warm water from the ASHP to give hot DHW as like you we will have LPG for cooking. But doing the numbers I reckon direct electric ( using e7 as well ) works out better.

 

Thats were i'm drawn towards at the moment.

I will be having PV, stove with boiler and then everything else with E7

 

May get a small ASHP down the line but not sure,  i'll see how the bills look.

[joe90]

4 hours ago, DeeJunFan said:

 

Thats were i'm drawn towards at the moment.

I will be having PV, stove with boiler and then everything else with E7

 

May get a small ASHP down the line but not sure,  i'll see how the bills look.

Yes, we plan an ASHP running from E7 during the late night to bring the slab and tank up to temprature just before E7 stops and topping it up as required later ( if required) lots of south facing glass to warm slab during sunshine, as per JSH an electric inline  modulating heater to bring warm water up to hot as required only for kitchen, shower and bath, for all others warm is sufficient (storing warm water rather than hot gives much less heat loss from a tank). Also as per JSH circulating water round the slab even when the ASHP is off to even out the temp within the slab and take heat from hot places to cooler ones. We will be having a wood burning stove but only a tiny one as the house will be very insulated and quite air tight and frankly a short burn will be more than enough to keep even SWMBO warm