Greenhouse Heater Problems

balloo_2

Just another question could any of you proper job Gardeners explain to me when i used to have a Greenhouse i had a parafine heater for the chilly nights but wat used to happen every time i used the damm thing when i got up in the morning the greenhouse glass would be covered in soot i asked some ppl and they said ur flame is too high turn it down. So i did but the same thing happened every time until one day in my temper i threw it out and low and behold no more soot :rotfl: and soon after no more greenhouse either, because i gave it to my father. but i have always thought about it and what was the cause. And now i am older and hopefully wiser i am thinking of starting again. :eek:

Davesnave

If I were you, and you're serious, I'd get an electric heater. Paraffin is a low tech, wasteful and very much outdated solution. I know it costs to have electric laid on (not very much if you know what you're doing) but electric heaters only take energy when the temperature falls, whereas paraffin ones have to be lit in advance and then run regardless of what the temperature is doing. Paraffin heaters also increase humidity, which isn't a good thing in the middle of winter.

Sooty flames on paraffin heaters are caused by having the wick up too high or a dirty, untrimmed wick. The flame should be blue, not yellow.

If you can't/won't lay electric on, then bottled gas is an alternative to paraffin and I believe many gas heaters can be responsive to temperature.

Incidentally, my electric heater has been running for about 15 years now and, because I took it apart & re-set the thermostat (you only need a screwdriver and a cold night!) it only comes on below 0 degrees C. As it is a blower heater, I stick a plant label in front of it, which blows away if it comes on. You be amazed how little it fires-up in the average winter, even though it is protecting a 25' (insulated) greenhouse.

alanobrien

I beg to differ with the previous poster. Paraffin heaters may be low tech but they are also low cost to run compared to electricity and this is after all a money saving site. Keep the wick trimmed and the flame set to the correct height and you should have no problems. I have never experienced soot or excessive humidity - compared to the outside that is and humidity is a parameter i constantly measure as i grow exotics.
Other options like calor gas type heaters are available but i have not looked at those myself. It may be worth doing a direct capital and running cost comparison against all three methods if your serious about heating a greenhouse.

balloo_2

Thank you all for ur advice but you would not have believed the amount of soot that was covering my greenhouse had to wash it all off constanly and the heater was bought new and from day one it produced soot The bit about the blue flame was interesting my flame was always YELLOW so problem solved.:grouphug:

Davesnave

Paraffin heaters may be low tech but they are also low cost to run compared to electricity and this is after all a money saving site.

Sorry, just don't believe it. Paraffin heaters require you to predict when they will be needed & therefore run at times when they are just wasting energy. Also there is the problem of remembering, and being there to remember. A friend of mine had a few drinks one night and forgot: that was costly!

katiel

I have tried many paraffin heaters over the years. I've got frustrated by the wick holders that seem to get damaged really quickly, I've had throw out all my bubble wrap at one point because it went black overnight and couldn't be cleaned, and I was hopeless at remembering to turn it on and off - especially when it meant a run down the garden in bad weather. I've also noticed the price of paraffin rising pretty sharply over the last few years. So my boys bought me an electric heater and heavy duty cable which I plug into my external power supply - and it's brilliant! I've even overwintered two lemon trees in the greenhouse this year. I don't expect it to add much to the electricity bill as it only cuts in below a certain temperature, so I'm all for it.

mjr600

I'd agree with the electric brigade, a cheap portable heater with a temperature cut in/out has to be a better bet. My greenhouse , a small 8x6, never drops below 10 at night, no nasty fumes and never comes on in daylight thanks to the sun and an automatic window opener.

No nasty fumes either.

Davesnave

I don't think i've ever seen parafin burn with a blue flame. It's always yellow as far as i am aware. Anyway, the soot is not something i have seen either, they do say you should turn the flame down just until it stops smoking to eliminate soot.

Well, yes, I agree it is never 100% blue, but there is a point at which it looks blue sideways on with only a little yellow. I'm old enough to remember a whole range of paraffin heaters, including some that used to have a chromium surround and a central dome that glowed red, probably in imitation of some electric fires of the time. As a student in the sort of place immortalised by 'The Young Ones,' these were our only source of heat. Mind you, we had the last laugh during the power strikes in the 'Winter of Discontent!!'

alanobrien

Davesnave wrote: »

Sorry, just don't believe it. Paraffin heaters require you to predict when they will be needed & therefore run at times when they are just wasting energy. Also there is the problem of remembering, and being there to remember. A friend of mine had a few drinks one night and forgot: that was costly!

No need to predict anything thats what the weather on TV is for. I guess it depends how you use heaters and how experienced you are with them. Nothing wrong with electric, but its way to costly even with a thermostat and without one, well a second mortgage may be required given power costs these days.

Davesnave

alanobrien wrote: »

No need to predict anything thats what the weather on TV is for. I guess it depends how you use heaters and how experienced you are with them. Nothing wrong with electric, but its way to costly even with a thermostat and without one, well a second mortgage may be required given power costs these days.

Sorry to bring the big guns in, but 'Gardening Which?' agrees with me:


What are the options?

Electric

If your greenhouse has an electricity supply, a thermostatically controlled fan heater is ideal, provided it's designed for a humid and wet environment.
Sixty per cent of Gardening Which? readers who heat their greenhouse use a fan heater – they're convenient, efficient and safe when used with an RCD (residual current device) to turn off the power if there's a fault.
They're the cheapest to run too.
Bottled gas

If you don't have or don't want to install an electricity supply, go for a bottled gas heater with a thermostat – but bear in mind gas bottles are bulky and heavy.
The heaters are also trickier to switch on than electric ones and have no fan, so cold spots are more likely, particularly at floor level.
Gas heaters also produce lots of water vapour, so greenhouse vents need to be open, otherwise grey mould and the like will thrive.
Good ventilation is also a must to ensure the heater doesn't run short of oxygen and start giving off toxic gases such as carbon monoxide – but ventilation means precious heat will be lost.
Paraffin

These also need good ventilation, and we found the ones we tested needed topping up with alarming and inconvenient frequency.
Also, we're yet to test a paraffin heater we're happy with safety-wise.



I only quote all this to prove I'm not a raving looney as regards the cost, which in my mild part of the country has been minimal for a good number of climate-changed winters. The whole point of my first post was that the thing has been off far more than it's ever been on. Personally, I think 'Which?' are over exaggerating when they say you need 2kw for an 8'x6' greenhouse, as mine at 25x10 has never had more than 1.5kw and nothing's died.

quickstepqueen

I have used a paraffin heater for the last 3 years because we live in a rented house with the greenhouse some distance away from the property.

It is difficult. After lighting the wick I would always turn it down until the flame was almost out. The flame would glow blue but after a couple of minutes it would then rise into yellow and be about the right height (as recommended in the instructions.) I haven't had any soot doing it this way.

I personally find the paraffin heater a pain. For example, if I've had it on over night I have to make sure I'm up first thing (irrespective of the late night I've had) to make sure it's turned off before the sun gets round to the greenhouse and cremates everything! Very difficult as others have said to regulate the temperature.

As for cost. Back in early March I was paying £3.99 for a 4-litre tub of paraffin. By the end of March it had increased to £4.75 and just 2 weeks later had increased again to £6 a tub (from the same garden centre.)

I was using a tub a week which works out very costly!!! The last 2 weeks (now the seedlings have been potted on and had a week or so to settle) I've covered the trays at night with the proprgator lid or newspaper. The cost of paraffin just doesn't make it viable to grow your own anymore. (Dad did manage to get me some paraffin from B&Q using his over 60 card so it worked out at £4.50 for a tub but still expensive.)