Lin Posted December 27, 2017 Share Posted December 27, 2017 Hello everyone ! A post just to introduce myself Doing a conversion using builders. I'm new to a lot of this energy saving building stuff and overwhelmed to be honest. Impressed by the knowledge and advice given on the forum. Main problem as i can see is that hub and i do not have time to do a lot of the detailing required to get things as "right" as a lot of you guys would do on your own places. And we only have a year to complete the build . Still dithering about what energy source to use gas (mains close by) or ASHP. gas would be an easy quick cheap decision but ASHP seems to be another nightmare of beaurocracy for RHI, a more 'unproven' technology, lower water temps and therefore slower heat up time for UFH etc, yet we feel the future of green energy is electricity. My head hurts. I dare say I will post for advice on this and other stuff soon. Be gentle and speak slowly ! Link to comment Share on other sites More sharing options...
Redoctober Posted December 27, 2017 Share Posted December 27, 2017 Hi @Lin and welcome to the forum. I'm sure others will be along once they have surfaced and or sobered up but from my understanding, if you are able to connect with gas, then that should be your preferred option. But please don't take my word for it, as I too am on here to educate myself as much as possible, from this wonderful friendly resource. Enjoy and good luck with the project. PW. Link to comment Share on other sites More sharing options...
Gone West Posted December 27, 2017 Share Posted December 27, 2017 Welcome to the forum and good luck with the build. I would also go with gas if it was available. Link to comment Share on other sites More sharing options...
MikeSharp01 Posted December 27, 2017 Share Posted December 27, 2017 Hi and welcome to THE forum. Yes gas is a good option even if a bit counter intuitive, there is an old item HERE that sets out the issues and takes a reasonably big picture view of the costs and emissions. The whole field is somewhat shifting as government policy and global understanding of ecological systems evolves. The article suggests that provided you can keep your COP (Coefficient of Performance) above 3.05 then you might beat natural GAS however to achieve this may well be hard work and if you take a look at the @JSHarris blogs you can perhaps see that to keep the COP high requires careful control and some luck with environmental factors. There is, of course, nothing to stop you having both - many here do, this would in theory allow you to run the ASHP when you can get above 3.05 COP and the GAS at other times but once you factor in the climate costs of making both items of plant, the ASHP and the Boiler, along with the dual infrastructure and mixed infrastructure you may well arrive at other conclusions and go for just the one. However to run a gas heated UFH (Under Floor Heating) system for instance requires quite a bit more infrastructure if you want the boiler to work at its most efficient output and there is also the interesting, and perhaps most challenging, complication of DHW (Domestic Hot Water) to add to the mix which tends to swing it more in favour of GAS but this is dependant on the size and type of boiler. Finally and perhaps most crucially there is the option of free electricity, after you write off the cost of installation, to run the ASHP if you have PV (Photo Voltaic) generation system. This then brings the cost of the electricity down and makes the ASHP an improved option with the additional possibility of storing excess electricity in something like the SUNAMP system (Other options are available) that can be used to provide DHW from the excess electricity. Essentially - not straightforward and dependant upon your feelings about how 'eco' you want to be and whether that is on a global warming scale, big picture, or local scale - just you keeping your costs down and doing as much as possible. Hope that helps many other will pile in. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted December 27, 2017 Share Posted December 27, 2017 Welcome. Yes, at the moment if you have gas, then use it. The problem with all heat pumps (excepting hybrids) is that they don't give great efficiency when heating hot water. The RHI is also a nightmare, as to claim it you been to jump through a lot of hoops, including using a certified installer, and the certified installers charge WAY more to install the kit because they know you're claiming the RHI......... If you opt to use a gas combi boiler, then you can also use energy stored from the excess from a solar panel array, using a Sunamp PV. This effectively fits ahead of your combi for hot water and either means your combi doesn't have to run at all (perhaps in summer) or that it runs less at other times, using preheated water from the Sunamp PV. It's a good compromise, as it allows the use of gas to get decent hot water temperatures, yet reduces gas use by utilising excess electricity generated from solar panels. Link to comment Share on other sites More sharing options...
Lin Posted December 27, 2017 Author Share Posted December 27, 2017 Thanks for the welcomes and really helpful replies everyone. Very helpful summary Mike and JSH I am interested in tha sunamp concept being married up with a PV system. The fog is lifting. 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted December 27, 2017 Share Posted December 27, 2017 Another option to consider if you are looking at using a low grade heating system, like under floor heating, is a hybrid ASHP, such as the Daikin Altherma Hybrid: https://www.daikin.co.uk/en_gb/product-group/hybrid-heat-pump.html . These combine an ASHP to give low temperature water, (so the efficiency is pretty much always very high) and then boost that temperature to usable hot water temperatures using a small built in gas combi boiler. The result is that the heat pump always works with a high COP (coefficient of performance) and the amount of gas used is decreased because the water is preheated. The downside is that they can be costly, and there is no provision for making use of excess electricity from solar panel generation, if you are looking at fitting them. You could add a Sunamp PV to such a set up, but the costs are beginning to stack up, and you may well be better off with a straightforward Sunamp PV and gas combi system. Link to comment Share on other sites More sharing options...
Pocster Posted December 27, 2017 Share Posted December 27, 2017 Hey. Even though we have gas nearby I made a conscious decision not to use it ( or foolish ) . ASAP seems to be our answer. but you have e to call it on cost and ethics ....... good luck ! Link to comment Share on other sites More sharing options...
pdf27 Posted December 27, 2017 Share Posted December 27, 2017 One thing to pay attention to is the gas standing charge - been doing a few fag-packet calculations recently and for a 150 m2 Passivhaus the standing charge means that the running costs of an ASHP and gas boiler are essentially the same. That’s going to make a hybrid system very unlikely to be viable unless you’re going to have a gas connection anyway. In that case, heat pumps make sense if you want cooling, but not otherwise. Link to comment Share on other sites More sharing options...
MikeSharp01 Posted December 27, 2017 Share Posted December 27, 2017 1 hour ago, pocster said: ASAP New acronym in this space - any ideas: Link to comment Share on other sites More sharing options...
MikeSharp01 Posted December 27, 2017 Share Posted December 27, 2017 (edited) 4 minutes ago, pdf27 said: That’s going to make a hybrid system By Hybrid I assume you mean both Gas Boiler and ASHP (Now sometimes known as ASAP) We will have gas because the other half likes to cook with it! Edited December 27, 2017 by MikeSharp01 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted December 27, 2017 Share Posted December 27, 2017 The Daikin hybrid does offer cooling as well as heating, and from what I've heard, it works very well indeed. Not cheap though, and perhaps better suited to those with LPG, because it massively reduces the gas usage. Link to comment Share on other sites More sharing options...
pdf27 Posted December 27, 2017 Share Posted December 27, 2017 1 hour ago, MikeSharp01 said: By Hybrid I assume you mean both Gas Boiler and ASHP (Now sometimes known as ASAP) We will have gas because the other half likes to cook with it! Before you get mains gas, work out how long a 47kg bottle of LPG would last you and at what cost. Hobs use very little gas in real life - even a 47kg bottle is probably too big. Link to comment Share on other sites More sharing options...
Nickfromwales Posted December 27, 2017 Share Posted December 27, 2017 1 hour ago, JSHarris said: The Daikin hybrid does offer cooling as well as heating, and from what I've heard, it works very well indeed. Not cheap though, and perhaps better suited to those with LPG, because it massively reduces the gas usage. Yup. Plus those on LPG still get to cook on gas . Lower consumption when on LPG is something to look into imo. Link to comment Share on other sites More sharing options...
Onoff Posted December 27, 2017 Share Posted December 27, 2017 Was thinking about LPG at one time but I didn't have the bottle... 1 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted December 27, 2017 Share Posted December 27, 2017 2 minutes ago, Onoff said: Was thinking about LPG at one time but I didn't have the bottle... ? ? Link to comment Share on other sites More sharing options...
Ferdinand Posted December 27, 2017 Share Posted December 27, 2017 (edited) Has @Onoff got his windows in yet? Can we defenestrate him for that joke? On LPG, we used to have one for cooking .. family of 4 on electric AGA with gas hob ... and it was roughly one bottle a year. I think it was the red one. Edited December 28, 2017 by Ferdinand Link to comment Share on other sites More sharing options...
Onoff Posted December 28, 2017 Share Posted December 28, 2017 Getting the feeling the LPG joke tanked.... 2 Link to comment Share on other sites More sharing options...
Ferdinand Posted December 28, 2017 Share Posted December 28, 2017 3 hours ago, MikeSharp01 said: New acronym in this space - any ideas: ASAP probably does not have a place in the construction vocabulary. ASAPB, now ... " ... But ... " is probably quite familiar to us all. F Link to comment Share on other sites More sharing options...
le-cerveau Posted December 28, 2017 Share Posted December 28, 2017 6 hours ago, JSHarris said: The Daikin hybrid does offer cooling as well as heating, and from what I've heard, it works very well indeed. Not cheap though, and perhaps better suited to those with LPG, because it massively reduces the gas usage. They do but it is not available in the UK!! I tried. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted December 28, 2017 Share Posted December 28, 2017 6 hours ago, le-cerveau said: They do but it is not available in the UK!! I tried. Officially they don't programme the cooling function, but it is inherently there, as the heat pump uses it every time it defrosts. Our Glowworm (a re-badged Carrier) doesn't officially have a cooling mode, but the reality is that it does, just like they all do, and it's not hard to programme it to get it working. All that's needed with the Daikin is to reprogramme it to enable the cooling function, probably ten minutes of work for someone that knows the intricacies of setting one up. Link to comment Share on other sites More sharing options...
Lin Posted December 29, 2017 Author Share Posted December 29, 2017 On 27/12/2017 at 19:19, pocster said: Hey. Even though we have gas nearby I made a conscious decision not to use it ( or foolish ) . ASAP seems to be our answer. but you have e to call it on cost and ethics ....... I get what you mean. No regrets about spurning gas then ????? Link to comment Share on other sites More sharing options...
Pocster Posted December 30, 2017 Share Posted December 30, 2017 (edited) Nope none ! :-) ASHP of course !! Edited December 30, 2017 by pocster Link to comment Share on other sites More sharing options...
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