Author Topic: Heat mat experiences  (Read 1720 times)

Plantinyum

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Heat mat experiences
« on: April 16, 2022, 05:30:11 PM »
I bought a heat mat theese days ,to help germinate some cacao seeds. Its just the usual type one, cheap and with no controller. I tried it for one hour and at room temp it got quite warm, at the surface close to 40C. Funny enough ,i find myself scared and cautious of using it since i have read at places people had bad experiences with them.

Anyone had a modern horror story with a heat mat ??

brian

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Re: Heat mat experiences
« Reply #1 on: April 16, 2022, 08:40:00 PM »
I've used these fairly extensively to warm seed trays, bagged seeds, and quail/eggs.  I have a half dozen of them, various no-name chinese types from amazon, all same basic design. 

They seem to work reliably as in I've never had one simply stop heating, but they tend towards too being too hot so you might want to verify with thermometer to be sure you aren't cooking your seeds/plants.  I had one melt a bit of polystyrene foam insulation once.  I'd avoid putting it near anything highly flammable.  If you're really worried you could find one with a fuse or buy a fuse and wire it in so it can't consume more than the rated wattage.

simon_grow

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Re: Heat mat experiences
« Reply #2 on: April 17, 2022, 12:58:23 AM »
Do yourself a favor and get a digital heat mat thermostat. It’s relatively cheap and you’ll be able to dial in the temp.

Simon

Plantinyum

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Re: Heat mat experiences
« Reply #3 on: April 17, 2022, 02:56:41 AM »
I've used these fairly extensively to warm seed trays, bagged seeds, and quail/eggs.  I have a half dozen of them, various no-name chinese types from amazon, all same basic design. 

They seem to work reliably as in I've never had one simply stop heating, but they tend towards too being too hot so you might want to verify with thermometer to be sure you aren't cooking your seeds/plants.  I had one melt a bit of polystyrene foam insulation once.  I'd avoid putting it near anything highly flammable.  If you're really worried you could find one with a fuse or buy a fuse and wire it in so it can't consume more than the rated wattage.

Yes, i had put it on top of a styrofoam piece and had little space between the seed tray and the heat mat. I thought i must suspemd the heat mat in the air somehow and not touch any surface so the heat does not overheat the surfaces. Wonder if cooking aluminium foil can be placed at least at the bottom of the mat to radiate the heat from the surface....


Do yourself a favor and get a digital heat mat thermostat. It’s relatively cheap and you’ll be able to dial in the temp.

Simon
i am thinking of bying a more expensive one, that has a controller in it.OR  I found a bunch of cheap to expensive controllers in alixpress, any brand or characteristics i should be searching for ?

Jagmanjoe

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Re: Heat mat experiences
« Reply #4 on: April 17, 2022, 05:46:15 AM »
For those that want to have a larger surface area to heat, anyone ever consider a single waterbed with a waterbed heater.  It would include a thermostat and I would think they might be readily available used.  Or perhaps one of those heaters under a flexible kiddie pool with a little water and perhaps very light dose of liquid fertilizer for periodic nutrient uptake of potted plants, slightly warming the solution to help encourage the root system uptake.

Crap, now my mind is really going - overthinking possibilities.  What about adding an underwater speaker, lol.  But seriously on the sound issue, has anyone tried utilizing music?  This is an article that not only talks about it possibly help plants grow but also gets into the way it affects insects, etc.
https://pistilsnursery.com/blogs/journal/music-and-plant-growth-heres-what-the-science-says 
« Last Edit: April 17, 2022, 09:05:05 AM by Jagmanjoe »

Jack, Nipomo

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Re: Heat mat experiences
« Reply #5 on: April 17, 2022, 10:07:03 AM »
Had a thermostatically controlled heat mat burn a hole in the mat and left a burned spot on the greenhouse wooden shelf.  Internal part apparently shorted out.  It had been in use over 2 years.  Replaced it with another, but aware of the potential danger.  It is not near the house.  Mat does speed up germination of seeds and offer warmth during winter for sensitive plants.

Plantinyum

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Re: Heat mat experiences
« Reply #6 on: April 17, 2022, 10:55:50 AM »
Had a thermostatically controlled heat mat burn a hole in the mat and left a burned spot on the greenhouse wooden shelf.  Internal part apparently shorted out.  It had been in use over 2 years.  Replaced it with another, but aware of the potential danger.  It is not near the house.  Mat does speed up germination of seeds and offer warmth during winter for sensitive plants.
well that sure adds some fuel to my fear of using the mat, eather way until i find a way to make the usage as safe as possible,i made a greenhouse for the cacao seeds, i covered the radiator with nylon and that keeps the temp around constant 25 C.
Yes i would not be as hessitant to use the mat outside, but i have the seeds now, and now its still wintery weather here so i cannot place the tray anywhere outside.

Seanny

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Re: Heat mat experiences
« Reply #7 on: April 17, 2022, 12:16:21 PM »
Use a layer sand below and above mat.

simon_grow

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Re: Heat mat experiences
« Reply #8 on: April 17, 2022, 01:19:53 PM »
I use one similar to this one.

VIVOSUN 48"x20.75" Seedling Heat Mat and Digital Thermostat Combo Set https://www.amazon.com/dp/B074N2TTHP/ref=cm_sw_r_cp_api_i_CGG5JQYZ52V1VD7VXW4S?_encoding=UTF8&psc=1

I’ve had it maybe 8-9 years but an older model and it still works fine for me.

Simon

Plantinyum

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Re: Heat mat experiences
« Reply #9 on: April 17, 2022, 03:58:24 PM »
Use a layer sand below and above mat.
What a clever idea, will try that !

I use one similar to this one.

VIVOSUN 48"x20.75" Seedling Heat Mat and Digital Thermostat Combo Set https://www.amazon.com/dp/B074N2TTHP/ref=cm_sw_r_cp_api_i_CGG5JQYZ52V1VD7VXW4S?_encoding=UTF8&psc=1

I’ve had it maybe 8-9 years but an older model and it still works fine for me.

Simon
looks nice, i will go for a set like this , maybe this same one,just need to have more spare money , hopefully the link works in a few months so i can go back to it...

Daintree

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Re: Heat mat experiences
« Reply #10 on: April 18, 2022, 04:45:43 PM »
I use the cheap ones with no controllers all the time in my greenhouse and have never had any problem with them. I set plant trays with ridged bottoms right on top of the mats, put my little pots in the trays, and put a cover on them at night, take the cover off during the day. Been using them for years and haven't killed anything. And I do germinate cacao seeds that way.

Carolyn

pagnr

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Re: Heat mat experiences
« Reply #11 on: April 18, 2022, 05:54:10 PM »
You should monitor the temperature of the germination media, not only the mat temperature.
If the mat has no controls except on/off, can you put it on a plug in timer.
Some of those have day and night or dials to set multiple times.

Plantinyum

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Re: Heat mat experiences
« Reply #12 on: April 19, 2022, 02:05:23 AM »
I use the cheap ones with no controllers all the time in my greenhouse and have never had any problem with them. I set plant trays with ridged bottoms right on top of the mats, put my little pots in the trays, and put a cover on them at night, take the cover off during the day. Been using them for years and haven't killed anything. And I do germinate cacao seeds that way.

Carolyn
thank u, its begginning to sound like not all of them do problems ,but prolly just some deffective ones. I havent had the time to try Seanny's sand idea, but bought trays yesterday and will need to do it. Yeah i am extra coutious about this since i will have to place this in my house, i could place it in my gh but its colder in there and will be more difficult to heat the seeds.
However i am not in such a hurry becouse the seeds are in a tiny greenhouse, a nylon over a radiator and then another layer of nylon over the seed tray with air space between them that is warmed by the radiator heat. They have been there for 3 - 4 days now and they are sprouting up slowly  , the temp stays around 20- 24 .
I a day or tho the heating sistem will be turned off and i will have to use the mat then ...

You should monitor the temperature of the germination media, not only the mat temperature.
If the mat has no controls except on/off, can you put it on a plug in timer.
Some of those have day and night or dials to set multiple times.
well timing is not a problem since i am at home most of the time, its just the max temp that wories me, i tested it for an hour and right on the mat the temp was around 40 C , with room temp around 20. I know that the soil temp will not be as hot, especially when i leave some space between the mat and the tray, so in this case i may need all the heat that the mat can provide. I found by my test of it that anything in contact with the heat mat prevents it from exchanging the  heat, thus creating hot spots.
I have the tendency of complicating things, but i got several ideas form the tread and will post what i ended up doing as a setup with the mat in a day or two.
« Last Edit: April 19, 2022, 02:27:41 AM by Plantinyum »

simon_grow

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Re: Heat mat experiences
« Reply #13 on: April 19, 2022, 11:51:15 PM »
Using sand above or below my help with preventing fires or burning but the insulation the sand will provide will almost render the heat mat useless. Heat mats use quite a bit of electricity and I prefer to put mine on top of lightweight insulation like styrofoam. This will significantly decrease energy usage.

Putting your heat mat on concrete will also help prevent fires and burns but concrete can be a heat sink with relatively high thermal mass.

Simon

Plantinyum

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Re: Heat mat experiences
« Reply #14 on: April 20, 2022, 01:25:00 AM »
Using sand above or below my help with preventing fires or burning but the insulation the sand will provide will almost render the heat mat useless. Heat mats use quite a bit of electricity and I prefer to put mine on top of lightweight insulation like styrofoam. This will significantly decrease energy usage.

Putting your heat mat on concrete will also help prevent fires and burns but concrete can be a heat sink with relatively high thermal mass.

Simon
yes i also placed it right on top of a styrofoam piece and thats when it got the hottest. Dunno i will try the sand and see what happens.  Will place a thinner sand layer on top and a thicker on bottom.
« Last Edit: April 20, 2022, 01:29:37 AM by Plantinyum »

Francis_Eric

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Re: Heat mat experiences
« Reply #15 on: April 20, 2022, 09:01:19 AM »
wouldn't a food cooler be the best it's cheap, and if a fire starts inside it will extinguish it self with no air since lid would be closed.

maybe some seeds need less water , but couldn't not tell you which

I brought 4 or 5  black sapote seed to Florida to Guerilla grow , and one sprouted the seed at home didn't
I do not know if it was in my jeans mini pocket the whole time (or if it ever was plus I changed )
 or in backpack , but was in 40's at night I brought them dry.

Hey you could always put them you know hidden from everyone.

pagnr

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Re: Heat mat experiences
« Reply #16 on: April 20, 2022, 09:34:13 AM »
"If the mat has no controls except on/off, can you put it on a plug in timer."
"well timing is not a problem since i am at home most of the time"
Sorry, I could have been clearer. If the heat gets excessive after while running the heat mat, maybe you could use the timer to run it in an ON/ OFF cycle to let the mat cool, then heat back up again. Not exactly a thermostat, but might control excessive heat ?

Francis_Eric

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Re: Heat mat experiences
« Reply #17 on: April 20, 2022, 09:39:42 AM »
FOrgot PErlite is not a flamable thing couldn't you rest it on some ?

I wouldn't imagine it being a heat sink ?
I know they use it in the swimming pool industry , for insulation but I am no expert on heat sinks)_

Lava rock is a poor conductor of heat it is porous  like perlite (this is where I get my assumption from)

Good Idea Pagner gonna get me one of those plug in timers
 (not for plants at the moment for not over charging Lithium batteries in computers when I go to sleep
the heat it is the most degrading thing for them)
« Last Edit: April 20, 2022, 09:45:24 AM by Francis_Eric »

Seanny

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Re: Heat mat experiences
« Reply #18 on: April 20, 2022, 10:34:27 AM »
I put all inside a picnic cooler.
Extremely low thermal loss.

Plantinyum

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Re: Heat mat experiences
« Reply #19 on: April 21, 2022, 03:02:06 AM »
Thanks for all the help everione, yes i was thinking of using a food cooler, i have one thats guite big and will prolly suffice, but then i will have to place a nylon as a top since when the seeds start sprouting they will need some light.

Again theres a chance that the food cooler is too small for the tray of seeds so i may just assemble one with styrofoam pieces and this will also prolly work just fine.will have to check...
I will take some pics once i organize myself to do the thing prolly saturday, lately i have been very bisy with plant matters,  meanwhille the seeds are comfortable in their present occupation.
I need to do an yard update theese days ,i only do not have plants in my bed, yet ..... ;D ;D
« Last Edit: April 21, 2022, 03:09:14 AM by Plantinyum »

mbmango

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Re: Heat mat experiences
« Reply #20 on: April 21, 2022, 09:03:16 PM »
I have a cheap one, and put it on a piece of foam.  I use an old aluminum food tray on top to spread out the heat a bit. Also makes an effectively larger mat out of a smaller one.  Throw an old clear tote over it all.  I think the sand instead of the tray sounds like a great, and safer, idea though.

W.

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Re: Heat mat experiences
« Reply #21 on: April 22, 2022, 03:13:26 AM »
I have a couple of basic 48"x20" heat mats with no timers or thermostats. I have always kept them on a cedar plank table I made, with nothing between them and the cedar. I have never had a problem with them, and they have never caused a single bit of damage to the cedar table. But, one safety precaution I always take with them is that I never leave them plugged in (on, basically) when I am not at home or am asleep. Since my seedling trays have always been kept inside a climate controlled area (my house) and never get below a certain temperature, leaving them unplugged for hours like this has never seemed to cause any germination problems with citrus, jaboticabas, tomatoes, etc., but I have never tried germinating cacao or other "ultra" tropical plant seeds.