[grinling]

Can I use a parrafin heater in polytunnel. Potting shed does not stay warm enough. Would use heater at night only. This is for seedlings.
Thanks

[DD.]

A polytunnel gets cold at night as well.

Depends how big the tunnel and heater is.

[grinling]

Still warm in it this morning, car said 3.5. Using 2 heaters one small one big.
Fingers crossed.

[DD.]

Overnight temps here are forecast to get lower, fortunately not below freezing. What have you got in the tunnel?

[grinling]

Prob everything which shouldn't be there, but it would be impossible to heat a room warm enough in this house. If it grows great, if not will try when it is warmer.