JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 26 minutes ago, Declan52 said: Yeah any that would normally be sold back to the grid is used to heat the water. The device is one of these. https://www.marlec.co.uk/product/solar-iboost/?v=79cba1185463 Last year I got near £480 for the amount I generated plus £65 for the excess I sold back. Not sure how I would calculate the amount it saved me by heating the water. As the tariffs have all changed you would get less though. Thanks again @Declan52 this is really useful. Can you give me a bit more info? What size is your house What size is your PV setup? Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 55 minutes ago, JohnW said: According to the as-designed SAP report... (which uses 0.15 U-value for external walls, which will actually be closer to 0.19 now we've changed the spec) DHW - 2500 kWh/year Space Heating - 5200 kWh/year Sorry @dpmiller I'm not sure if I have supplied the correct figures, here. Which section of the SAP 2009 report should I take them from? Link to comment Share on other sites More sharing options...
Declan52 Posted March 11, 2018 Share Posted March 11, 2018 39 minutes ago, JohnW said: Thanks again @Declan52 this is really useful. Can you give me a bit more info? What size is your house What size is your PV setup? House is 220sqm and the PV is a 4kw system. Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 4 minutes ago, Declan52 said: House is 220sqm and the PV is a 4kw system. Thanks, similar to ours then. Who installed your PV, and are you able to give me some idea of installation cost? Link to comment Share on other sites More sharing options...
dpmiller Posted March 11, 2018 Share Posted March 11, 2018 is the roof tiled yet? Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 2 minutes ago, dpmiller said: is the roof tiled yet? No, we're only at foundation stage Link to comment Share on other sites More sharing options...
Declan52 Posted March 11, 2018 Share Posted March 11, 2018 39 minutes ago, JohnW said: Thanks, similar to ours then. Who installed your PV, and are you able to give me some idea of installation cost? They cost around £5k and where installed by sun renewables from dromore but I think they have ceased trading. Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 Thanks @Declan52 Link to comment Share on other sites More sharing options...
Nickfromwales Posted March 11, 2018 Share Posted March 11, 2018 3 hours ago, JohnW said: If I scrap the "intelligent heating controls" what's the best way to operate the UFH whether it's on Oil or ASHP? Some basic reasonably priced controls that don't operate the garden sprinklers via thumbprint or voice recognition . They call them programmable room thermostats and they start from as little as £60. . Link to comment Share on other sites More sharing options...
Declan52 Posted March 11, 2018 Share Posted March 11, 2018 I just put in a standard heatmiser room stat. Yes I wanted to be able to change the room temp on my phone when I was driving home but in reality it takes maybe 2hrs for my slab to warm up and increase the room by a single degree so that aspect is never needed. I set my room temps when I moved in and they are more or less the same over 3 years later. 21 degrees in the living rooms and kitchens and 19 in the bedrooms and hallways. Ufh heating just works away in the background and won't need much attention once you have it set up. All that intelligent heading control stuff is class to look at and to show off when you have visitors but really do you need it. Keep it simple always works out best. These are the stats I have and at a £10 cheaper than @Nickfromwales reckons they do my job the very best. https://www.amazon.co.uk/Heatmiser-PRT-Programmable-Room-Thermostat/dp/B000S0I2D4 Link to comment Share on other sites More sharing options...
Nickfromwales Posted March 11, 2018 Share Posted March 11, 2018 To have a stove with a boiler you'll need a whopper of a TS ( thermal store ). You'll need a lot of additional heating / plumbing / control paraphernalia which will cost much more to buy, install and maintain. You'll also need a heat leak ( dump ) radiator too, unless it's not a 'solid' fuel burner. Have 'the chat' and see if a WBS ( wood burning stove ) that doesn't heat water, will suffice? Anyhoo. Gas is a box-ticker. Easy, neat and simple. If your dead sure gas-is-a-coming-to-them-there-parts then I'd seriously consider it, just because getting an ASHP fitted may be difficult, but getting it repaired / maintained may be even harder to achieve. ( I just realised you have a hot press not an airing cupboard ). Most plumbers can fit a gas boiler so you'll find much more support available for that. FYI if you go for a Vaillant boiler then converting between LPG and Natural Gas is literally a 5 minute job with a flat blade screwdriver and a U-gauge. No stripping of the boiler / changing of jets etc . Other manufacturers may do similar but I know the Vaillant does. I fit mostly Baxi or Vaillant. Great appliances. Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 21 minutes ago, Nickfromwales said: Some basic reasonably priced controls that don't operate the garden sprinklers via thumbprint or voice recognition . That made me laugh - Keep it simple, a rule that can be applied to absolutely everything. 24 minutes ago, Nickfromwales said: They call them programmable room thermostats and they start from as little as £60. . Thanks the Salus IT500 has caught my eye - have you any experience of it? 9 minutes ago, Nickfromwales said: To have a stove with a boiler you'll need a whopper of a TS ( thermal store ). You'll need a lot of additional heating / plumbing / control paraphernalia which will cost much more to buy, install and maintain. You'll also need a heat leak ( dump ) radiator too, unless it's not a 'solid' fuel burner. Have 'the chat' and see if a WBS ( wood burning stove ) that doesn't heat water, will suffice? Thanks for the marriage guidance - we both want a real fire and have assumed that we might as well be heating the water at the same time, but it sounds like we would be introducing quite a bit of complexity and therefore cost. If I'm not back by tomorrow send help!! 12 minutes ago, Nickfromwales said: Gas is a box-ticker. Easy, neat and simple. I'm coming round to this conclusion. Back to Keep it simple. What's an "airing cupboard" Thanks for the heads up on the Vailiant boilers. 1 Link to comment Share on other sites More sharing options...
Declan52 Posted March 11, 2018 Share Posted March 11, 2018 Can you move the position of your wbs to somewhere more central so it will heat the whole house when it's lit. Mine will keep mine warm for over 3 days when it's lit. A wbs with a back boiler will need a lot more wood/coal as well. Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 25 minutes ago, Declan52 said: I set my room temps when I moved in and they are more or less the same over 3 years later. 21 degrees in the living rooms and kitchens and 19 in the bedrooms and hallways. Does this not use loads of fuel? (are you using Oil?) 26 minutes ago, Declan52 said: Keep it simple always works out best. I couldn't agree more. Thanks for the heads up on the Heatmiser controls. Would you mind telling what your whole setup is? I suspect I'll end up with something very similar to yours. Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 8 minutes ago, Declan52 said: Can you move the position of your wbs to somewhere more central so it will heat the whole house when it's lit. Mine will keep mine warm for over 3 days when it's lit. A wbs with a back boiler will need a lot more wood/coal as well. Unfortunately not, but I have toyed with the idea of having an MVHR extract above and in front of the wbs, to help distribute some of the heat around the house. I've absolutely no idea if this is sensible or not, it's a question for another day. Link to comment Share on other sites More sharing options...
Declan52 Posted March 11, 2018 Share Posted March 11, 2018 if you put the work in now and spend the money on the fabric then you vastly reduce your heating needs. Then it's only the dhw that you need to worry about. I have ufh on the ground floor and rads upstairs. I heat a 350l thermal store using a wood pellet boiler with excess PV used as well. In the winter the pellet boiler is set to come on in the morning for 3 hrs. During this time I have the rads set to also come on for 30 mins to warm upstairs. Just my luck my wife and kids are cold people so they need heat in the morning to put their clothes on and brush their teeth. I used just over 1.5t of pellets this year which was £340. Your system should work just the same. You heat a large body of water and then use it for ufh/rads or for dhw. Won't matter if its oil or gas heating it up. 2 Link to comment Share on other sites More sharing options...
Nickfromwales Posted March 11, 2018 Share Posted March 11, 2018 9 minutes ago, JohnW said: Unfortunately not, but I have toyed with the idea of having an MVHR extract above and in front of the wbs, to help distribute some of the heat around the house. I've absolutely no idea if this is sensible or not, it's a question for another day. Do not do that. The heat won't transfer but the smoke will. MVHR flow rates don't lend themselves to transferring heat about. @JSHarris had elaborated on this more than once, so read and evaluate.....it's all here if you ask or dig . Link to comment Share on other sites More sharing options...
JohnW Posted March 11, 2018 Author Share Posted March 11, 2018 14 minutes ago, Nickfromwales said: Do not do that. The heat won't transfer but the smoke will. MVHR flow rates don't lend themselves to transferring heat about. @JSHarris had elaborated on this more than once, so read and evaluate.....it's all here if you ask or dig . Thanks @Nickfromwales, sounds like that's not a questions for another day after all. I dread to think how much time I've spent reading posts on this site, but still feel I know very little. Thanks again. Link to comment Share on other sites More sharing options...
Nickfromwales Posted March 12, 2018 Share Posted March 12, 2018 10 hours ago, JohnW said: I dread to think how much time I've spent reading posts on this site, but still feel I know very little. Me too. . Better to read and ask than pay and regret. Keep reading. It's free....but priceless. . 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted March 12, 2018 Share Posted March 12, 2018 All a bit tricky, but 4 things to know first. The energy demand of your house The energy split e.g DHW and Space heating The installation costs Energy prices. Energy pricing for NI is here: Electric https://www.nihe.gov.uk/latest_tariffs Oil http://www.consumercouncil.org.uk/energy/home-heating-oil/#recent Gas (with a lot of digging) http://www.consumercouncil.org.uk/energy/gas/ You also asked about the difference between an ASHP and a gas boiler installation. It really just comes down to the different temperatures that are delivered. ASHP has a lower temperature delivery to keep the efficiency high, a gas, oil or electric boiler delivers at a higher temperature. All that means in practice is that you need different surface area for the emitters (radiators). Lower the temperature, larger the area. For space heating via under floor heating it may just come down to a different size buffer tank and a few valves. Plumbers can give better detail on that. Link to comment Share on other sites More sharing options...
dpmiller Posted March 12, 2018 Share Posted March 12, 2018 Not convinced the average plumber is any use for anything other than oil/gascombi/ rads. Finding one as good as @Nickfromwales truly is a needle in a haystack. 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted March 12, 2018 Share Posted March 12, 2018 20 minutes ago, dpmiller said: Not convinced the average plumber is any use for anything other than oil/gascombi/ rads. Finding one as good as @Nickfromwales truly is a needle in a haystack. 1 Link to comment Share on other sites More sharing options...
JohnW Posted March 12, 2018 Author Share Posted March 12, 2018 54 minutes ago, SteamyTea said: All a bit tricky, but 4 things to know first. The energy demand of your house The energy split e.g DHW and Space heating The instillation costs Thanks @SteamyTea, I have the as-designed SAP report but I'm not entirely sure which figures to lift as our energy demand, maybe you could tell me which ones from this selected extract; Section Water heating (kWh/year) Space heating (kWh/year) Calculation of Energy Ratings 2573.0868 5214.5496 Calculation of dwelling emissions for regulations compliance 2573.0868 6375.9114 Calculation of target emissions 2901.8514 18840.2881 Calculation of energy ratings for improved dwelling 1573.4793 5219.229 1 hour ago, SteamyTea said: Energy pricing for NI is here: Thanks for this info - it's very helpful. Thanks also for explaining the differences based on ASHP & gas/oil boiler. Link to comment Share on other sites More sharing options...
JohnW Posted March 12, 2018 Author Share Posted March 12, 2018 27 minutes ago, dpmiller said: Not convinced the average plumber is any use for anything other than oil/gascombi/ rads. Finding one as good as @Nickfromwales truly is a needle in a haystack. I tend to agree...on both counts. Link to comment Share on other sites More sharing options...
SteamyTea Posted March 12, 2018 Share Posted March 12, 2018 1 minute ago, JohnW said: Calculation of dwelling emissions for regulations compliance 2573.0868 6375.9114 That one I think. Link to comment Share on other sites More sharing options...
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