Topic: Polytunnel heater - advice please

[plot76]

I have two small poltyunnels, you can see them here http://plot76.info/poly.html

Does any one have any advice on what type of parafin heater I can use, or I am mad to think that I can?

Thanks

[Larkshall]

The Parasene heaters are quite good. Your poly-tunnels look to be 1 metre X 3 metres so I would suggest a twin burner model (you can always keep the wicks low if its too hot). Pity you're not near me as I have two spare ones now that I've gone over to a thermostatic fan heaters.

[plot76]

Thanks for the tip, my local garden store has twin burners for about £15, I only want to heat one tunnel (they are 3.5m by 2m not a bad guess from looking at a photo!!)

[tim]

What are you going to grow in them?

[plot76]

The tunnel I wish to heat will have chili peppers(several varieties) planted in the ground and then racks with seeds, the other tunnel I don't intend to heat, so I guess I just need enough heat to germinate seeds.

[Larkshall]

I note that your polytunnels are remote from your house. This being the case an electric propagator in out, but it may be possible to fix up a propagator by having a sheet of aluminium or galvanised steel fixed up with say, a couple of hurricane lamps underneath with a layer of sand on top (to spread the heat) and normal unheated propagators on the sand. As my Stewart electric propagator is only 20w and takes 2 standard seed trays, it should be possible to make the propagator bench on the basis of 4 standard seed trays per hurricane lamp. It should do the job and be pretty economical.

[Larkshall]

I carried out an experiment today. Checked the temperature of the Stewart propagator, result 25C. Made up a propagator with a galvanised butchers tray with about 1" of sand in it, standing on twelve bricks (slightly higher than the hurricane lamp), temperature 20C. I've put two trays of cuttings in it.

[Larkshall]

Update on the hurricane lamp propagator.

It is still working well, maintaining a temperature of 60F (16C). Paraffin consumption is moderate. Using a Chalwyn Tropic lantern I refill night and morning, there is oil remaining when refilled. Cost for paraffin is around 50p a day, this is more expensive than electricity for the Stewart electric propagator.