Can I calculate savings for turning down/off individual radiators?

Reed_Richards

ChasingtheWelshdream said:

I am sitting in a room with the largest radiator which is set to 3. It is cold so presumably TRV has activated and turned off. The room thermometer says 13.9 degrees. 

Either the TRV has activated to turn off the radiator or the valve is stuck in the off position (valves that are off all summer occasionally stick).

ChasingtheWelshdream said:

The boiler thermostat is elsewhere (upstairs hallway) and set to 15. It is still firing as that room is currently 14.8.

It's possible that your upstairs hallway is cold and draughty and its radiator is too small so it struggles to reach the set temperature.  Are any of your other radiators on or is the one in this hallway the last one still on?

ChasingtheWelshdream said:

The thermostat can’t go anywhere else sadly. It is a new Hive system that has been problematic from the outset (on another thread) and won’t communicate with the boiler anywhere else.

The normal modern configuration is that there is a control box that is wired to the boiler and a room thermostat that communicates wirelessly with the control box.  It must be the wireless part that is giving you problems; perhaps the control box position could be moved to make the wireless communication better?

ChasingtheWelshdream said:

I am genuinely scared for the future. 

Our house is large and old with 12 radiators, most of them undersized for the rooms, which I am gradually upgrading. The only warm room is when we have the woodburner lit.

I'm afraid that upgrading the radiators will make your house warmer but may increase your gas usage.  If you can upgrade the radiators and turn down the boiler flow temperature you may be able to get your boiler to operate more efficiently.  You have my sympathies.  There has been a massive increase in fuel prices and I fear some people will find that they can no longer afford to keep their homes adequately warm.    

  

 

markin

For that thermostat location you will have to have it around 2-4c higher to account for heat raising, Keep bedroom doors closed and bedroom trvs set low to get the downstairs close to your desired temperature.

Mstty

You mention changing radiators one at a time.

Are you doing this yourself or getting someone it?

Do you drain the system first and follow the correct procedure?

Maybe this is why you have trouble getting some radiators up to temp.

markin

The system may need to be balanced again so all rads heat up at the same time.

ChasingtheWelshdream

Reed Richard: The TRV isn’t stuck, I have checked. The upstairs hallway as yet has no radiator but is close to an open bedroom door.  This is the closest I can get it to the receiver box.

The Hive issue is essentially the hub, signal booster, receiver and thermostat will not maintain a reliable connection. Hive tech support have said it is due to the layout, distance and thick walls our the house and have been very little help. It was discussed in detail on another thread I won’t bore you with it now.

Most radiators are very old type 11, I am upgrading to larger type 22. My hope is they will radiate more heat over a possibly shorter period, or at least be effective in heating each room if not. Boiler flow is set to 60, lower than this they do not get beyond warm.

Markin & Mstty:

I am doing the radiator work. Yes, system is drained down each time and do it properly.  I take time to rebalance when needed and the system itself is in good order. 

I should clarify, the issue isn’t with the radiators not heating up, or heating up irregularly. But that despite a large gas useable the house itself is rarely warm. 

My original question was whether the economies I had thought we were making, can be quantified in any way on a room-by-room basis.

I appreciate all your thoughts, thank you.

Mstty

I think your original question was answered in post 2 then👍

Olly_J

ChasingtheWelshdream said:

I should clarify, the issue isn’t with the radiators not heating up, or heating up irregularly. But that despite a large gas useable the house itself is rarely warm.

I know you mentioned wall insulation, but what is the loft like? I live in a 1930's semi and had to put a lot in to stop excessive heat loss through the ceilings, up to around 500mm over most of it now, and that works well. Over December it looks like you were averaging around 80Kwh a day, so the heat has to be being lost somewhere

ChasingtheWelshdream

The loft itself is 300mm as it was increased to meet building regs when the roof was replaced. There are other areas of coombed ceilings in the bedrooms which will be overboarded with Celotex in the near future. There is a grand plan.

The only places we can’t insulate eventually are two solid floors which would cost too much.

getmore4less

I think calculating micro changes won't be easy due to too many variables

You would need to be capturing quite a lot of data to have chance of interpreting at gas use level.
Temps in all rooms, outside temps, temps of the rads and perhaps multiple readings a day for consumption.
that means buying sensors.
 
I have bought some temp/humidly sensors that record hourly 24hrs and then store max min for month
That is showing us what the temp is to what it feels like, we can start turning down everything down to a comfort point.
(once we get heating back)

They were £5 each(ebay UK seller) got 5 we have 12 radiators to play with 2 have been off for years in rooms we don't use
https://ams.buy.mi.com/uk/item/3204500023

What you might be able to do is more macro measurements.
turn off completely in a room monitor temp and use for a day or two then add heat and see what happens

As you need/want to cut use it may be a case of prioritising sell rooms have some on frost only and keep the main one more comfortable.

Even with more clothes 15c has been too low for us in the room we use. 


For your room not getting warm you need to calibrate your TRV
This is where a recording thermostat comes in handy to see the range and tell if it is coming on/off during the test period

See what temp range the room gets too for each setting
if it has been consistent say 3~=13.9c  try it on 2 and 4 and see what happens. 

As you have been upgrading have you not gone to smart TRV that do their job better  and can have multiple temp time settings a day.


It might be you need to dump your hive or as said review the location of the parts or get something that will work.

Might have to go wired or mesh based options.
(one for the home automation and more experienced heating  guys)

Reed_Richards

ChasingtheWelshdream said:

Most radiators are very old type 11, I am upgrading to larger type 22. My hope is they will radiate more heat over a possibly shorter period, or at least be effective in heating each room if not. Boiler flow is set to 60, lower than this they do not get beyond warm.

Boiler flow at 60 will give you good economy of operation but from what you describe it is too low for your current radiators.  Traditionally boiler flow was 80 C and return 60 C and your radiators may have been specified for these temperatures.  Incidentally, a touch test is not a reliable indicator of radiator effectiveness.  I have a heat pump and my radiators never get "beyond warm" but they are large enough in surface area that they still do the job.