Heating a single room

[ricky678]

Hi All,

Could sure use some help with a little heating / cost problem.

The house has gas central heating, a conventional system with a 40k btu boiler and radiators of about 25k btu / 6.3kw + h/water cyl.

I have a small room containing some delicate plants which must be kept at no lower that 15deg C - day and night.

Normally the central heating would be off at night and when out at work.

It would be too expensive to keep all the central heating on all the time, and have been using an electric fan heater to cover the times when the main heating is off.

However this is proving expensive in this colder winter so I wondered is I could use the central heating instead.

Thought about laying in a separate valve, pipes and thermostat for just this one room; ( not too difficult )
However would this cause too much strain on the boiler as I would have thought it would cause a lot of cycling ?

From my simple obersvations / calculations, the electric way needs about 750w per hour, worst case, which costs about 10p a hour.

Gas costs seem a bit hard to establish but running the whole gas central heating for 1 hour, say when getting in, uses .55 units on the gas meter or about 3p per hour for the whole 6.3kw, which seems a much better value if my figures are correct ?


thanks

Ricky678

 

[plummerman]

Doin this would not cause your boiler to cycle in fact it would do the opposite. But to do this you would have you establsh if your system is fully pumped or not. It would be a lot easier to convert a exisisting y-plan to a s-plan plus than altering all the gravity sercs etc. Then again there is the c plan plus if your water is gravity and your heating pumped this would allow you to keep the gravity srecs and zone your heating. hope this helps

 

[EliteHeat]

Assuming you are fully pumped then a cheap way of doing this would be to install an RF thermostat - programmable or not - and during the day manually shut down all other rads and move the RF stat into the delicate flower room and let it control this single room.

When you get home, put the stat wherever you want.

 

[mogget]

Gas costs seem a bit hard to establish but running the whole gas central heating for 1 hour, say when getting in, uses .55 units on the gas meter or about 3p per hour for the whole 6.3kw, which seems a much better value if my figures are correct ?

No, that doesn't sound right, 6.3 kWh worth of gas would be about 30p I would have thought, not accounting for pipework losses and efficiency (and not checking my tariff).

One thing I've noticed is that my gas bill uses two different definitions of 'unit', one being a kWh of heat, and the other being a cubic metre of gas. I think there's about 11kWh in a cubic metre of gas - no doubt someone else here will be able to give more exact figures.

 

[ricky678]

Plummerman

Doin this would not cause your boiler to cycle in fact it would do the opposite. But to do this you would have you establsh if your system is fully pumped or not. It would be a lot easier to convert a exisisting y-plan to a s-plan plus than altering all the gravity sercs etc

Sorry, should have said - its a fully pumped system, with 2 M/valves to rads / hwater pipes - think thats S system in todays language - so sounds like laying in an extra valve and thermostat for just the one radiator will work ok then - don't think I could afford those fancy RF thermostats EH mentions


Mogget

No, that doesn't sound right, 6.3 kWh worth of gas would be about 30p I would have thought, not accounting for pipework losses and efficiency (and not checking my tariff).

Thats why I was wondering if my figures were right ; - have just checked the gas meter readings again - and leaving out the btu and kw figures, the bottom line is if the whole radiator load only uses 0.55 units on the gas meter for a hours running from cold, thats only costing either 5.3p or 3.1p per unit according to my last gas bill, so just running the boiler for one radiator should be very cheap compared to the electric fan heater.


thanks

Ricky678

 

[plummerman]

you can pick an rf stat up for about 70 quid, it would be the easiest to install but then you have the trouble of going round turning valves off/on each an every time you go out. then you come home and house is cold cause heating didn't come on cause valves are shut etc etc. In my opoion the extra valves will be worth the extra money in the long run

 

[mogget]

Thats why I was wondering if my figures were right ; - have just checked the gas meter readings again - and leaving out the btu and kw figures, the bottom line is if the whole radiator load only uses 0.55 units on the gas meter for a hours running from cold, thats only costing either 5.3p or 3.1p per unit according to my last gas bill, so just running the boiler for one radiator should be very cheap compared to the electric fan heater.

Bear in mind that you will be charged per kWh - this is the 3.1p or 5.3p charge. Your gas meter reads 0.55 units (cubic metres) for an hour. There are roughly 11kWh (also called units!) in a cubic metre of gas, so you will be charged for 0.55 cubic metres x 11kWh per cubic metre = 6kWh (ish). 6kWh is 18.6p at 3.1p per kWh.

 

[ricky678]

mogget wrote:

Bear in mind that you will be charged per kWh - this is the 3.1p or 5.3p charge. Your gas meter reads 0.55 units (cubic metres) for an hour. There are roughly 11kWh (also called units!) in a cubic metre of gas, so you will be charged for 0.55 cubic metres x 11kWh per cubic metre = 6kWh (ish). 6kWh is 18.6p at 3.1p per kWh.

Ah - missed the kw conversion bit on the bill - see what you mean now.
Still think the price of the extra pipe work etc will be soon repaid by the lower running costs of the c/h.


many thanks

Ricky678

 

[oilman]

Why not just have a propagator tent in the room for the plants? You could rig it yourself to save expense if necessary. All this other unnecessary sophistication is pure waste. You need a solution to a problem, not a compounded problem.

 

[ricky678]

Oilman wrote:

Why not just have a propagator tent in the room for the plants? You could rig it yourself to save expense if necessary. All this other unnecessary sophistication is pure waste. You need a solution to a problem, not a compounded problem.

Yes, that would be true for a few plants but I am talking about a small room and a lot of plants - a greenhouse or conservatory would be ideal but thats a lot of dosh for buying and heating.

 

[rssteve]

are these cannabis plants?

 

[oilman]

I wonder why I thought the same

It would still be cheaper to use an electric heater, and it would be far more reliable than a CH boiler.

What happens if your heating system breaks down?

 

[Agile]

A friend of mine grows delicate plants in a secret corner of his 12 acre wood in Devon.

But they live outdoors but as quantity is not a problem presumably the growth rate is not important.

Since these delicate plants need a lot of light the usual way would be to use electric lights to provide the light with heat as a byproduct.

I cannot see how anything other than electricity is going to be cost effective.

I suggest you add lots of insulation to reduce the heat loss.

Tony

 

[ricky678]

are these cannabis plants?

A friend of mine grows delicate plants in a secret corner of his 12 acre wood in Devon

Just hope I never go to court when you 3 are on the jury

Actually the plants are tropical orchids - they are better suited to indoors because they do not want direct sunlight - this would soon burn them up - they do however need a minimum temp of 15c to grow well - hence my need to keep the room at that temp - as the room has a southern aspect I do not need provide any additional lighting - the reverse actually, using a net curtain to provide the needed shading.

Like me you might think that keeping Orchids is a fringe thing, but as I found it is a low key but very popular interest and hobby worldwide - worth a look if plants and flowers are of any interest to you.