Kitchen Garden Forum

hi all,i have an 8x6 greenhouse at the top of my garden,its fully insulated with polythene using the appropiate clips to leave an air space between glass and polythene.down to the heating now
i use 1 thermo controlled propane heater,this runs of a 47k bottle (£30).the thing is i dont heat the whole greenhouse,the heater is positioned central under the right hand side staging,which in turn is fully cladded with polythene around it.the top bench of the staging is built of 3/4" ply which is also covered with polythene.on top of this is a layer of sharp sand covered with a sheet of micropore black polythene.i normally sow into module trays which are then covered with yet another bit of poly (to retain heat and moisture.the heater only heats the small area underneath the staging with the heat rising upwards.i can maintain a bench temp of 60c whilst the greenhouse temps never drop below 45c.i have 3 wireless thermometer probes,1 is positioned on the bench 2 is free standing in the greenhouse,the 3rd is outside.all max min and current temps are displayed on a little monitor in front of my pc.i know it sounds complicated but its so simple to operate and didnt cost that much.thers also a temperature alarm which sounds if somethings going wrong,i may have not explained it very well in words but if anyone wants some pictures of the setup id be more than happy to send some.it all makes sense when you can see it, sorry for going on a bit peterf

Very interesting. It is much on the lines of what I am doing except the source of heat for the main 3x6ft.propogator bench section is a 250 watt element sandwiched between the aluminium bench and an overlay of duplicate panels. The main part of the greenhouse is merely heated against frost to protect stock plants.
I am intrigued by the remote sensors especially the necessary to get the data onto the PC. With 3 propogators and the inside and outside temperatures that makes 5 channels and now we are on Euro systems one can only use 3 channels, besides which that system has insufficient range to reach my greenhouse. It seems that some complete data transmitter is needed, I would be prepared to wire in a serial link if necessary. The other possibility is a data collection in the greenhouse for later analysis. I look forward to your reply with great interest.
Allan

hi allan,sorry for not explaining in more detail,the temp readings are displayed onto an acctim base unit that i have sitting in front of my pc.it has 3 channels so can monitor upto 3 sensors.they are brilliant for keeping an eye on things and save them trips to the greenhouse to check thermometer.your setup seems to be based on the same principal as mine.i was going to buy an electic heating mat also,but i thought they were a bit expensive for what they did,so i just set about making my own its worked very well for the last 2 years.i find it excellent for taking cuttings of summer bedding.using 84 plug modules i can have upto 700 cuttings on the go at anyone time,by keeeping them well misted and with the bottom heat they root very quickly.all the best peter.