Suitable Heater for largish propagator ?

Hi,

Have a home made propagator that needs about 200w to heat, so we fitted a 180w tubular heater ( with overhead fan) and while it does have the output to maintain the heat needed, because of its slow heat up and the long release of heat after the desired temp is reached and power removed, it does cause quiet a large temperature swing.

A fan heater normally does the job, but not found anything readily available with an output of 200/250w.

Have seen the reptile infra red ceramic heaters , are they suitable for plants or would they just destroy them ?
Swell Ceramic Heat Emitters

Any other type of more instant heater we could use ?

thanks

 

How about soil heating cables?

 

Hi,

Thanks, but would need several cables and they are equally 'slow' devices.

 

I would be concerned that the infrared emitters could "toast" the young plants. In my opinion the advantage of soil heating cables is that they are buried in a layer of sand and although slow to heat and cool with a thermostat in the sand layer; they would give a constant temperature due to the heat storage capacity of the sand layer.

 

You can get soil heating cables up to 600watts here,Soil Warming Cable only place I've looked, so you can probably find cheaper elsewhere.
I've been running one of these,with a thermostat for about 25 winters, and it still works.
You just bury most of the cable and leave some exposed around the edges.

The question of getting a steady temperature is in a great part down to using a really good thermostat.
Forget the correct term, but you need one that reacts quickly to temperature rise and fall, and keeps to one or two degrees of the temperature set.

The other advantage of soil warming cables is the heat is spread evenly without hot or cold spots.

 

This is my ''little'' propagator, it is very old and I bought it second hand from a nurseryman who was retiring. It has a heated base and a thermostat - and a probe to stick in the compost. I think it is 93watt. I cover the base with capillary matting.
You can buy similar roll out mats to put on the greenhouse staging (or the kitchen table if you like)
Heat mats to help germination

 

This is the kind of system I really miss....

 

Would love one, but don't think my neighbours would ! (small urban back gardens)