JohnMo Posted October 20 Share Posted October 20 Just been looking at ASHP monitor system, it shows the flow and return temperature among other things. Sun has been out since lunch time. You can see the floor absorbing house heat. For context the UFH pipes are at the bottom of 100mm of concrete, the main rooms to get solar gain are covered in glued down oak floor or carpet. The ASHP is in full WC mode with no mixers etc and circulation pump runs 24/7. Rise in temp is 0.5 degs on flow and return (green/red line) over 2 hrs. Link to comment Share on other sites More sharing options...
SteamyTea Posted October 20 Share Posted October 20 Do you have a log of room air temperature? Link to comment Share on other sites More sharing options...
JohnMo Posted October 20 Author Share Posted October 20 I have a log of the temperature in the hall. Which is behind the rooms that get solar gain. Our lounge got to 24 peak, currently at 21.2 (5pm), dip in temperature is when I opened the door to outside (OAT peaked at 13 degs) and coincides with the hottest temp in lounge. Link to comment Share on other sites More sharing options...
JohnMo Posted October 20 Author Share Posted October 20 The things I find interesting The floor consists of UFH pipes in 56T of concrete. So a lot of stuff to heat up. Looking at this in a bit more detail Last time the heat pump ran it stopped at 0630. Sun came out at 1300. Flow and return temperature was slowly falling from the heat pump stopping (circulation pump stays on), and flow temp started to rise at 1400. The flow and return temperature started to rise 1 hour after the sun came out, all window blinds were closed as room temperature started to rise. Link to comment Share on other sites More sharing options...
SteamyTea Posted October 20 Share Posted October 20 From your PV generation data, along with a bit of trig, you can probably get a good estimation of the direct solar beam power that is hitting your floor. That may account for the modest temperature rise. You may also find that your MVHR is supplying air at an elevated temperature as the OAT rises. It is often very hard to unpick what is happening. Correlation and PDF charts of the different inputs may show what is having the greatest effect. Link to comment Share on other sites More sharing options...
ringi Posted October 23 Share Posted October 23 (edited) The solar gain maybe on external walls resulting in them losing less heat then the weather compensation assumes. Remember people and electrics etc are also adding heat to the building. Edited October 23 by ringi Link to comment Share on other sites More sharing options...
JohnMo Posted October 23 Author Share Posted October 23 31 minutes ago, ringi said: The solar gain maybe on external walls resulting in them losing less heat then the weather compensation assumes. Remember people and electrics etc are also adding heat to the building. Today no sun, UFH not gaining temperature, very slight fall. Sunny side of house is timber clad on a 100mm ventilated cavity, but sunny side of house also has 50m² of glazing. Walls are externally insulated ICF. Although heat losses would be slowed down, air temperature rise through solar gain is at play. Floor just soaking it up and showing in the slight uplift in UFH temperature. Link to comment Share on other sites More sharing options...
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