ASHP or MAINS GAS?

[Steve Williams]

Hi and thanks for reading my query

I am renovating an terraced Edwardian house which will be well insulated. The gas boiler is old and the entire Central Heating system is a mix of ugly rads, normal piping and microbore, in short it needs replacing.
I will be fitting UFH regardless of the ASHP/Gas question as I prefer it and the floor boards need lifting and insulation installed anyway.
We have a mains gas supply.
Is an Air Source Heat Pump a better choice than gas?

Steve

 

[Jimbob]

At the moment, I would stick with mains gas. ASHPs don't really financially add up when compared to natural gas at the moment

 

[markfxy]

I'd go with gas and when your boilers kn-ackered in 5 years time go for an ashp they'll be even more efficient then

 

[Pipes Plumbing]

If you're on mains gas it'd be mains gas for me over an ASHP sadly, for the following:

1- More costly per kW/h output compared to mains gas.
2- Even at 3.5 COP the CO2 out per kW/h is hight from ans ASHP at the moment due to power production being so dirty and transmission losses so high (up to 90% in some remote areas!!)
3- More expensive upfront for the ASHP compared to a gas boiler.
4- With the new standardised energy tariffs on there way in, unless the gas supply is totally disconnected, you will be liable for a standing charge anyway, even if it is used for cooking only...

Just my take on it... I struggle to make them stack up when anyone's on mains gas at the minute (and I'm a biomass engineer so favour renewables!)

 

[eaton]

Got one to do, I'm looking at hybrid it, so hw is off gas boiled and all heating on heat pump, then if ever needed gas can kick in. Works well, will be very good as he has 4kw pv, lad I met at Samsung other week said his 4kw pv pretty much powered his 9kw ashp for whole of April which is impressive

 

[eaton]

Ill add I've got a 16kw Samsung at my house now, 1975 4 bed detached all rads, ive specced rads for 45c as it works out £90 a year better than 50c so was worth tiny outlay. Double glazed and insulated 20 years ago, loft too. I'm actually logging it with Samsung as a trial unit. I've got a separate elec meter that is reading everything on heating side ie ashp, immersion, controls, pumps the lot. I'm saving daily data and its looking great against the oil I had when I moved in 2 months ago, I'm posting most of results on twitter page @kfiskplumbing and Facebook page Kfiskplumbingandheating.com so if interested take a look. At least I can give actual real time results. Cost to heat my house yesterday inc hw was 69p, day before 78p

 

[Jimbob]

Have you got a heat meter to see what you're actually producing?

Definitely starts adding up when comparing to oil I must admit.

 

[eaton]

No don't see need for it, end of day you just want to know run cost. I can work out cop at any time using a calc

 

[Jimbob]

Worth looking at though, we've got a Panasonic setup with meters and heat meters, give a better indication of how efficient it is rather than just averaging with a COP factor. And it could be that you may require a heat meter to get any future RHI payments

 

[eaton]

I offered mcs to send me one they said no! Said ok sod you then

 

[peteheat]

My advice to the OP is insulate very well forget todays regulations and double up if possible, draught proofing, good quality windows screen doors etc.

Top quality heating controls especially for UFH, preferably a thermostat in every room back to a manifold as your heating control centre.

Now you have a foundation for the future, today you fit a quality gas boiler, however you leave the pipes in place to fit your heat pump to so the installation cost is not crazy.

From my experience the majority of failures with heat pumps are caused by salesmen who don't understand their product or construction in general so they sold them as a "one solution suits all".

The new way of thinking should be future proofing our homes, from what I can see there is no free heating system coming along in the near future and our traditional fuels (even wood) are getting more expensive be it gamblers on the stock exchanges, political turmoil or the fact that as gas and oil get more expensive homeowners just won't be able to afford them.

 

[Howsie]

An air-source heat pump is a good choice. Yes it is a more expensive little bit but well worth.

Cricket and rice?

 

[Steve Williams]

Thanks to everyone who responded! We opted for a gas boiler with a solar thermal. UFH downstairs, rads upstairs. Very effective.

 

[Phil_Plumb]

excellent choice, the solar thermal will heat up the water in the cylinder by x amount of degrees C that the required energy from the boiler will be less to heat up the cylinder to the correct temp.

Saving gas and saving energy using a tried and trusted tech!

That being said, if gas keeps going the way it is, my boiler will be coming out and all 3 out of 4 fireplaces will be opened up (frontroom already done) i will put in a back boiler with pump to an indirect cylinder to provide my HW via a 3 port valve for the rads.

have a plentiful supply of free logs anyway!

 

[Steve Williams]

Oh and a woodburner in the front lounge and a rainwater harvester for toilets and washing machine to up our Eco-credentials, the water tank only went in in May do is now nearly empty, doh!

 

[Dickie]

Not having read all the posts, but a good few. None of you so called ASHP experts have mentioned the COP of these units!! Also, if you had any small insight as to how refrigeration actually works you'd know that volume circulation is required for the optimum output & efficiency, so LLHs are not worth fitting, a buffer tank is always required.

A ASHP would never be as cheap to run as a modulating Nat Gas condensing boiler. OP don't listen to the ex-used car salesmen, it's all mince they talk.