Topic: Easy cold frame heating

[dicky]

I built a cold frame for this year, with no plans to heat it but tried a little experiement that might interest someone.

I put 2 2 litre bottles of hot tap water in the frame to see how much it could raise the temprature and it made a difference of nearly 3 degrees.

Over night with a blanket over the top to add protection this could make quite a difference on a cold night.

Hope it helps someone.


Dicky  8)

[katynewbie]

Sounds like a great idea...also free!!! My favourite price!!!

 ;)

[glow777]

As we take bottled water (tap not mineral  :-*) for our chickens this seems like a good idea. I could bring up the hot water when i shut my chickens in for the night, heat my coldframe and use the chilled water the next day.

[SMP1704]

Dicky  I tried your tip this morning and it definately is a top tip :D :D

This morning the temp in my mini greenhouse (4 shelves) was 3 c, so I put 3 2 lt bottles of hot water inside and within an hour the temp had risen to 10 c, when the temp outside was still around 4 c.

When I got home at 1pm, the temp inside the g/h was at 15c - at least 5c higher than it has been over the weekend, although the outside temperature was higher than today.

Thanks for the top tip ;D.  Since Thames Water have announced the hosepipe ban, I thought I would use my son's bath water to fill up the bottles this evening.  I know we should all be showering, but a nice warm bubbly bath at night sends him right off to sleep  ;D ;D

[John_H]

Using old vacume flasks for slow heat release is a good method too.

You can regulate the heat loss by how much you unscrew the top.

[dicky]

Hi

I did consider the bucket of hot water but I thoguht the effect of condensation could cause fungal problems for young plants. Any heater will cause a bit of condensation but that is technically steaming them.

still deciding whether to invest £9 in a small parafin heater that should help

[Hyacinth]

As we take bottled water (tap not mineral  :-*) for our chickens this seems like a good idea. I could bring up the hot water when i shut my chickens in for the night, heat my coldframe and use the chilled water the next day.

How neat is that?
Useful top tip AND recycling!
 ;D

[Robert_Brenchley]

I used a paraffin heater in a greenhouse for years; it should work in a cold frame, but you do need a bit of ventilation. It's not only a matter of getting the oxygen in, you're also producing large quantities of water vapour, and need to get it out.