Hi,
I am having so much fun manually balancing my underfloor heating (UFH), but just to ruin my fun, I think it is ripe for automation.
I have found two options, has anyone got any experience with either of them? Does anyone know of any other options?
Would I trust these?
Not so sure..
Yea I am wondering that, I have contacted them to ask what delta T they control to, haven’t got clear answers from the manufacturers.
To be honest, all I really want is a thermocouple on flow and return for each circuit that I can use while adjusting the flow regulating valve (FRV) and also to monitor them as things will change over the long term such as room layouts or the short term like rooms getting a lot of solar gain dropping delta T.
For the long term changes I would just re-balance using the FRV but for the short term changes the auto-balancing valves would be very useful. I don’t like the idea of just trusting these devices to balance correctly though, particularly when they claim to be using AI…
I guess I could just use a couple of Terminal Block Breakout for DS18B20 - Shop | OpenEnergyMonitor to monitor, does anyone know of an actuator that is not just open / shut and not a black box so I can control it myself?
I’ve found that different floor coverings and perhaps sizings of rooms (number of heating loops that fit in) and where doors are and perhaps windows that are losing a bit more heat than the walls do, required different flow rates to get balanced comfort.
For example kitchen / hall floor is all travertine tile. In the lounge we have a very low tog carpet.
Without balancing the kitchen floor is around 1°C warmer than the hall and around 2°C warmer than the lounge.
The kitchen and hall need lower flow rates / throttling a bit to allow the lounge to be the same comfortable temperature.
Perhaps these auto systems can take that into account or work with temp readings you take and input?
You are right, the thing that is missing from these devices is measuring floor temperatures.
Not all floor temperatures are supposed to be the same though, it depends on the target room temperature and heat loss for that room.
| Floor Output (W/m^2) | Floor T (℃) | Room T (℃) |
|---|---|---|
| 29.87 | 23 | 20 |
| 40.99 | 24 | 20 |
| 52.39 | 25 | 20 |
| 64.02 | 26 | 20 |
| 75.85 | 27 | 20 |
| 87.85 | 28 | 20 |
| 100.01 | 29 | 20 |
| 112.30 | 30 | 20 |
| 124.71 | 31 | 20 |
| 137.23 | 32 | 20 |
| 149.87 | 33 | 20 |
| 162.59 | 34 | 20 |
| 175.41 | 35 | 20 |
| 188.32 | 36 | 20 |
| 201.31 | 37 | 20 |
According to this manual, Salus actuator holds 7°C dT at temperatures above 30°C and dT of 4°C below that. https://saluscontrols.com/wp-content/uploads/resources/THB2430/es/Quick-Guide.pdf
As I see it, these are useful when you don’t want to balance the loops if their length are different. Such actuators will handle that task automatically by monitoring the flow and return.
Thanks, that guide is very useful and confirms what I was told but wasn’t able to confirm.
The only thing I am wondering now is what would these valves do during defrost cycles? I don’t want the valves to shut and not have enough water left in the primary for the heatpump to defrost.