I haven’t tried it, but I did look, and the UFH cooling is limited to 18. I assume you’re running it with coil fan as the emitter in the settings? Is it a matter of using a shelly with humidity and temp to adjust the target temp? The unfloor lag might need a safety buffer, I guess.
Yeah the cooling controller automatically changes the circuit type to fan coil.
You can use any humidity/temperature sensor to calculate dew point, ideally you have one per room and then use the maximum dew point.
Managed to enable cooling in econet, but couldn’t get “Auto detect cooling” on MyHeatpump app (emoncms.org) to persist.
I extracted the (read/write) apikey from local emonhub config, went to https://emoncms.org/app/view?name=MyHeatpump&apikey=xxxxx, clicked the spanner, and enabled “Auto detect cooling”. Clicked on ‘Launch app’ and it shows the cooling periods, but if I refresh the page, use the readkey (as on the hub QR code), or go via heatpumpmonitor HeatpumpMonitor.org , it doesn’t show the cooling period.
Not the worst thing, but it means my local hub is showing SCOP 4.09, but HPM SCOP has now dropped to 3.99.
You need to rebuild the data by clicking on “Reload Daily Data” then Launch App on the MyHeatPump config after enabling cooling. Is your system shared on HeatPumpMonitor? If so, can you share a link? I’ll take a look
Yup - https://emoncms.org/app/view?name=MyHeatpump&readkey=3bef8848b5d49193c2f87a87d95e4629 and https://heatpumpmonitor.org/dashboard?id=876
Reload daily data gives me a popup “Failed to clear daily data”
Has anyone looked into using water cooler cassettes with the grant? Can you another circuit for cooling off the grant and use cassettes as opposed to rads for cooling?
Have you tried fitting fans to the bottom of the rads?
I have a Vaillant, and PWM-controlled fans (courtesy of @Andre_K 's controller) installed on a few rads, which do an excellent job of increasing radiator output when heating.
I have a cooling chip for the Vaillant, but haven’t got round to installing it; intrigued how it’ll work with rad fans as a ‘poor man’s fancoil’.
This definitely works nicely to shave a few degrees off in hot weather. There can be a lot of condensation though, which in older rads can cause rust to appear despite visually intact paint.
Does the dew point hysteresis not prevent condensation from forming?
I don’t have the dew point sensors, so no idea how they work. But in my experience any flow temperature above 15°C doesn’t do any appreciable cooling and once you go significantly below that you enter dew territory no matter what (at least with the typical German summer climate). If you’re desperate enough to run your system at 10°C flow rates you will see massive effects with a few fans below the rad. However, most radiators are not made for cooling so the cold water will not fully circulate through the rad but rather only sits in a small cold region. After playing with it for two summers with my type 33 and 22 rads I’d say it can work but with quite a few caveats. I’m looking to get an actual AC fitted in the house to take the edge off in summer.
Thank you, helpful to read some real world experience.
Would you be willing to share the caveats in greater detail? Trying to work out if it’s worth investing time in getting cooling working…
In my experience, it’s a waste of time with radiators. I don’t have first hand experience of using UFH for cooling, but I’ve heard that it can at least provide a psychological benefit of having a slightly cool floor. You really want to stay above the dew point to avoid damage due to condensation.
Fitting a fan coil circuit with fully insulated pipework and condensate drains is the way to go if you need cooling. But fitting a mini-split would probably be cheaper? Or use something like Midea Portasplit 12000 BTU Mobile Air Conditioner, Cooling A++/Heating A+, 42m², 39dB Silent Mode PortaSplit
Thanks; I enabled cooling yesterday, and as you say, the cold UFH feels nice but that’s about it.
Have you tried fitting fans to the radiators?
In hot humid weather, the dew point can be as high as 20C, the radiators won’t be able to provide significant cooling running at 20C even with fans
A large K2 will require a sets of 3 fans, which cost over £100 for a set, fitting these to all the radiators in my house would cost as much as a cheap mini-split while still providing an insignificant amount of cooling.
I’ve fitted 8x 140mm Noctua fans with a PWM controller courtesy of @Andre_K to a 1400mm K3 in our living room; running the fans at 100% does produce a noticeable cooling effect, so it’s not completely useless, even at the current humidity levels.
Running 2K above dew point hysteresis for the flow temp.
I have a metric ****ton of spare high-end 120mm/140mm fans, so will slowly fit them to the rest of the rads in bedrooms, especially our son’s which is south-facing and receives significant solar gain… in combination with an ‘aluminet’ external reflective shading fabric.
Does anyone know how to best calculate the total kW volume of fan coils I would be able to run for cooling purposes on a 6.5kW unit? If that’s even the right question…(SEER?). I am building a 230m2 house and have a 3.5-4.3 kWh estimated heat loss (MCS). I would like fan coils in the three bedrooms upstairs, the home cinema, my study, and ideally a big one onto the landing upstairs to try and cool the property down but don’t want to get too many that I don’t have the power to run them!
I was looking at Megawave’s fan coils, e.g.: 7KW Concealed Fan Coil Unit for Heating & Cooling
I tried cooling today. Yesterday my house stayed around 22.7 degrees, as I have good solar shading and low g-value on my tripple glaze windows. The house was around 20.6 today with the underfloor in cooling mode. We still haven’t moved in yet. The cylinder does have hot water in it, but there are no fridges running and no people in the house. Still encouraging enough. I reckon if I point a fan at the floor it will mix the stratified cool air around and help bring the temp down further.
It looks like cooling is showing correctly on HPM: https://heatpumpmonitor.org/dashboard?id=876
I noticed the monitor started showing properly last week, thanks! @glyn.hudson
UFH cooling here across 3 floors, new build detached, UFH across all floors, cooling set at 18-20C target temp depending on dew point of the day.
- Top floor with 2 fans pointing at the floor (27-28C, still lot better than outside)
- Middle floor around 25C, having a fan pointing at the floor does make a big difference. Around 28C if no fans
- Ground floor, feels damp, but otherwise a very comfortable 23C with no fans
- Relative humidity peaks at 75%
edit*
It looks fine on https://emoncms.org/app/view?name=MyHeatpump&readkey=3bef8848b5d49193c2f87a87d95e4629 which is the one I look at.
But not via https://heatpumpmonitor.org/dashboard?id=876
SCOP seems to be treating the cooling SEER as a positive, although the window COP still goes negative
Jaga, who have just opened an UK subsidiary down the road from me, appear to be supplying fanned units with condensate management that allow you to run below dew point. I’d certainly be looking at them if I was specifying for new build, or could be sure to insulate all pipework. Briza Net Zero - Jaga for Net Zero