canalsiderenovation Posted January 30, 2020 Share Posted January 30, 2020 I'm really liking the look of in roof solar for our bungalow and as we need to have all new tiles on the existing roof as well as the new extension roof it seems to make sense for an in roof system. Our plans don't have this on it for planning permission but do we need to specify this for building regs? Our slowest-architects-in-the-world are working on them currently and I've been reading about in roof solar with interest. We will have an ASHP (around 220m2 bungalow) with UFH which I've not explored yet makes, models etc but early conversations with builders we have noted insulation a priority (will post specs) and I'm thinking the in roof solar would be good for our own electrical use (work from home) and potentially divert some of this to a immersion heater. We would have a shower room and bath and another shower in a bedroom which would be frequently occupied by family. I love hot steamy baths as does my wife and long hot showers. Does anyone else have this set up? ASHP and in roof solar which diverts to immersion? Link to comment Share on other sites More sharing options...
ragg987 Posted January 30, 2020 Share Posted January 30, 2020 Yes, on our (now not so) new build. Works very well. See my profile for basic info. Just beat on mind ASHP will not get DHW as hot as gas boiler, so slow for that in you cylinder sizing to support your hot steamy habit. Our council planners told us that PV was permitted development so we did not have to show in the planning application. We mentioned it as a note with no detail on fit method. And if you should get a battery car or storage later the PV can support those too for lower bills. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 30, 2020 Author Share Posted January 30, 2020 13 minutes ago, ragg987 said: Yes, on our (now not so) new build. Works very well. See my profile for basic info. Just beat on mind ASHP will not get DHW as hot as gas boiler, so slow for that in you cylinder sizing to support your hot steamy habit. Our council planners told us that PV was permitted development so we did not have to show in the planning application. We mentioned it as a note with no detail on fit method. And if you should get a battery car or storage later the PV can support those too for lower bills. This is one of my worries re hot water. In our previous house I use to have a bath every night (gas). At the moment I crave working away from home in the hope I get a hotel with a bath (and heating)! Link to comment Share on other sites More sharing options...
SteamyTea Posted January 30, 2020 Share Posted January 30, 2020 Water at 48°C, which is not an unusual temperature for an ASHP to get too. Is too hot to bath in. So just a matter of sizing the store directly. In summer the ASHP will probably become redundant. Link to comment Share on other sites More sharing options...
joe90 Posted January 30, 2020 Share Posted January 30, 2020 I have a 5K ASHP with UFH and DHW cylinder heated to around 48’, I also have a large bath that I occasionally soak in. I have to add a small amount of cold water to it as @SteamyTea says! 48’ is too hot for even me. Because I don’t have to add a lot of cold water I have a fairly large 300litre DHW tank and even with visitors have never run out yet. Link to comment Share on other sites More sharing options...
ragg987 Posted January 30, 2020 Share Posted January 30, 2020 (edited) 2 hours ago, canalsiderenovation said: This is one of my worries re hot water Having lived with a 7kW ASHP that provides all our water and space heating for 330m2 and 6 people, I would say it is not a worry, just size the cylinder appropriately. As above from spring to autumn our solar PV provides a reasonable proportion of DHW requirement. Mrs ragg987 loves her very hot showers, through trial and error I found a setting of 45C to be the point at which she does not complain about it being cold. Easily achievable by an ASHP. If you intend to soak in the bath for a very long time and hence want top up the water temperature occasionally, I suspect you need the water to be delivered at a higher temp, maybe 50C. Not something I have tried with our system. Also consider lagging your bath to reduce heat losses. Edited January 30, 2020 by ragg987 Link to comment Share on other sites More sharing options...
Pete Posted January 30, 2020 Share Posted January 30, 2020 4 hours ago, joe90 said: I have a 5K ASHP with UFH and DHW cylinder heated to around 48’, I also have a large bath that I occasionally soak in. I have to add a small amount of cold water to it as @SteamyTea says! 48’ is too hot for even me. Because I don’t have to add a lot of cold water I have a fairly large 300litre DHW tank and even with visitors have never run out yet. If you do not mind me asking what is your elec bill on average? Link to comment Share on other sites More sharing options...
joe90 Posted January 30, 2020 Share Posted January 30, 2020 1 hour ago, Pete said: If you do not mind me asking what is your elec bill on average? very difficult to tell as the house is still settling down, during most of the year it’s DHW only and a typical month was £30, but I have a workshop with many many tools so can’t separate that out, our last jan bill was £120 . Link to comment Share on other sites More sharing options...
SteamyTea Posted January 30, 2020 Share Posted January 30, 2020 39 minutes ago, joe90 said: but I have a workshop with many many tools so can’t separate that out, I can, if I remember when I get home. 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 30, 2020 Author Share Posted January 30, 2020 When I adjusted the thermostat on the shower in the hotel when I was in a hotel this week it was somehere over 40 degrees but under 50, and I normally have my baths hotter! I blame living in a cold house for so long and I'm nesh. Well that puts my mind at rest. The builder we really are hoping to use has just installed a 4.5kw in roof system so is familiar with this which is bonus and working from home means I could make use of the solar PV running appliances etc. Link to comment Share on other sites More sharing options...
Pete Posted January 31, 2020 Share Posted January 31, 2020 23 hours ago, joe90 said: very difficult to tell as the house is still settling down, during most of the year it’s DHW only and a typical month was £30, but I have a workshop with many many tools so can’t separate that out, our last jan bill was £120 . ? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted January 31, 2020 Share Posted January 31, 2020 On 30/01/2020 at 10:36, canalsiderenovation said: Does anyone else have this set up? ASHP and in roof solar which diverts to immersion? Yes, this is pretty much our set up. We have 25 PV panels built in to the roof, with a peak output of 6.25 kW. We divert excess generation from them to heat our hot water, which needs ~6 kWh/day. We find that the PV supplies around 59% of our annual hot water requirement, so we only pay for about 41% of it. Our ASHP is only used to heat and cool our ground floor, but we could use it to heat hot water if we had a hot water tank (we use a Sunamp). 1 Link to comment Share on other sites More sharing options...
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