Mad Idea? Just a waste of time?

[Rorschach]

We don't have a radiator in our kitchen, we had to remove it in order to allow us to fit appliances and cupboards in a U shape right around the room (the kitchen is tiny, less than 4 sqM I think).

As such, the kitchen is the coldest room in the flat and we do get some condensation and mould on the outer walls at times.

The radiator feeds are still on the wall behind a cabinet. I wondered, is it a mad idea to run a loop of pipe under the cabinets, behind the kick stands, attached to the rad feed? The idea being the pipes would inject a bit of warmth into the room when the heating is running.
I reckon it could be done quite cheaply and easily using plastic pipe and a run of that length would probably put out almost as much heat as a small towel radiator would.

What do we think, mad?

[dewaltdisney]

Have a read up on Hydronic plinth heaters https://www.cef.co.uk/library/hydronic- ... 20solution.

These convector fan heaters are connected to the radiator circuit and work a bit like a car heater. We had a Myson convertor heater on the landing in a house we had. It had a diverter flap that blew through a duct into the bathroom or out onto the landing or blew both areas at the same time. It was very efficient as I recall, the thermostat would keep an even temperature.

I would say that you could easily fix one yourself as you could easily run the pipework and connect it for a couple of hundred.

Certainly worth a look.

DWD

[Someone-Else]

I didn't read the whole of the link given by Dewaltdisney as you have missed the point.
Yes the pipe would get hot, but it has too little surface area to work.
Take a towel rad, what does that have that your idea doesn't ?

RUNGS, the bits that go from one side to the other. If you were to add several rungs, and do it all in copper it may work, you would also have to add a bleed valve, or you will get an airlock.

[Rorschach]

Have a read up on Hydronic plinth heaters <span class="skimlinks-unlinked">https://www.cef.co.uk/library/hydronic- ... tion</span>.

These convector fan heaters are connected to the radiator circuit and work a bit like a car heater. We had a Myson convertor heater on the landing in a house we had. It had a diverter flap that blew through a duct into the bathroom or out onto the landing or blew both areas at the same time. It was very efficient as I recall, the thermostat would keep an even temperature.

I would say that you could easily fix one yourself as you could easily run the pipework and connect it for a couple of hundred.

Certainly worth a look.

DWD

Yeah it's the price that's the problem. I did look them up but they are several hundred £ and would require power which isn't easily available in the location I would need to fit it.

Oh and I probably don't have the depth needed, the kitchen is so small that only one side has full size base units, the other side has wall units and a slim worktop, so limited depth.

[Rorschach]

I didn't read the whole of the link given by Dewaltdisney as you have missed the point.
Yes the pipe would get hot, but it has too little surface area to work.
Take a towel rad, what does that have that your idea doesn't ?

RUNGS, the bits that go from one side to the other. If you were to add several rungs, and do it all in copper it may work, you would also have to add a bleed valve, or you will get an airlock.

I reckon the length of the loop I could run under the cabinets would have a greater surface area than a towel rad and would be spread across the kitchen. Could run it in copper I suppose, just thought plastic would be cheaper and easier so I could create a larger loop.

[Someone-Else]

Plastic would be cheaper, but copper conducts heat better.
If you look at Underfloor heating, it does use plastic pipe, BUT there is lots of it, and it is run up and down at close centres, you would get the same effect with a "ladder" of pipe work. Like wise look at a radiator, it's a series of channels close to each other for water to run through. Only saying.

[Rorschach]

I can get 25m of Polybutylene for about £50 and I think it would be flexible enough to not need any joins, could just do a single back and forth loop multiple times under the cupboards. I reckon even with it's low conductivity the sheer surface area would be enough.

[Rorschach]

Theoretically that could transfer 4kW

[dewaltdisney]

You need to have some form of convection. This can occur naturally if the warm air can rise and draw the cold air in to be warmed and create a cycle. This means finding a way to allow this air to pass upwards, not easy with worktops and plinths. If this is not achieved then the warm air will simply be trapped in a box under the cabinets and serve very little warmth transfer. That is why I suggested a plinth convector but as you say positioning would be difficult so it is not an option for you.

DWD

[Rorschach]

One end of the run of cabinets has an open gap to allow for the washing machine fill/drain hoses, also a couple of the cabinets have had their backs removed for ventilation purposes (to help deal with the condensation problems and let me deal with mould on the wall) so there is quite a lot of space for air movement around the backs of the cabinets. I could also add a couple of louvre vents to the plinth boards.

My main goal is to warm the cabinets really. The room itself is tiny as I mentioned and heat does pass from the adjoining room (sometimes we use a fan to push warm air into the kitchen) but the cabinets obviously don't benefit much. I put temp sensors in and while we have the rest of the flat around 17c the insides of the cabinets are often 9-10c.
Even with a plinth heater like you suggested I am not sure if that would get the heat in the cabinets, my suspicion is it would just blow into the open space and then out into the adjoining rooms.

[dewaltdisney]

Oh, I see,it was hard to visualise. I was thinking you wanted to warm the ambient temperature in the kitchen but I see what you are trying to do now.

DWD

[Rorschach]

Ah my apologies. No not really interested in ambient temp, we are only out there when we are cooking and that is obviously nice and warm.

Did some maths, worked out I can run a 600W heater for 1 hour per day for 12 years (at current elec price) for the same cost as buying the cheapest hydronic heater. This math assumes the hydronic heater is free to run, which it isn't of course.

So I am going to do an experiment running an electric fan heater under the cupboards, see how well that warms things up. If it works ok then I will look at installing something more permanent.

Would be quite happy to run electric for a couple of hours a day in the winter just for that room. Even if it was costing me say £20 a year in running costs, the time saved in maintenance each year would be worth that.

[Rorschach]

Fan heater in and will be doing tests. Once I get an idea of how much heat input is required I will then run a test using 100W light bulbs as a stand in for tube heaters.

If the 100W bulbs work then I will get some tube heaters for long term use.

[dewaltdisney]

I was in Home Bargains yesterday, my eye settled on electric heaters and I was amazed at how cheap they were. These new ceramic gauze-type high-output heaters were very cheap and a convector panel heater was only £15. I wonder if one of those £20 mini heaters might be an idea. I saw them in Dunelm https://www.dunelm.com/product/500w-plu ... 1000229792 Having said that they are probably too high output for what you want. An old electric blanket on a timer shoved under the cabinets would probably work.

DWD

[Rorschach]

That mini heater is pretty much what I am testing with. It's a 600W fan heater (but on a cord). We take it travelling with us as it's very compact and perfect in a chilly hotel room/caravan. It won't make the room properly hot but it will take the chill off a bathroom or supplement the central heating etc. Got it at Lidl for £5.

I will certainly take a look at other heater options. My suspicion is tube heaters will be the safest and most suitable but I am not sure if 100W or more will be required hence why I will do the test with 100W bulbs, I have the bulbs and I have spare light fittings and flex so it won't cost me anything in materials to test. My hope is that 1kWh or so per day should do the job.