Category Archives: Projects

Heat & Grow Machine – Growing veggies during winter

Who said growing veggies during winter was impossible?

What if creating a perfect climate for your plants during winter would cost just no electricity at all?

This is the first prototype I made two years ago of my Heat & Grow machine.


Since most houses are electrically heated these days, heating the house with the heating system or from the heat dissipated by the lights in the Heat & Grow machine will not cost you any additionnal electricity bill and plus, you have a bonus veggie season inside your house!

These are some other experiments I made. everything grown on those pictures were grown under artificial lights. at some point, corn was just too high to fit the machine!


I figured out here that aluminum paper was not a good idea, using PAR directional light pointing straight down is way more efficient!




Here is a graph combining the spectrum of various light sources and the plant absorbtion spectrum. All lines are from various sources, they have been added and scaled to fit all together. What’s interesting here is that, plant absorbtion spectrum is totally out of HPS light bulbs spectrum. Knowing that, I don’t know at all why everyone keeps growing under HPS. All the generated light from these ultra powerful bulbs is just not absorbed by the plant which is just pure energy waste.


I fugured out after many light bulb pattern attempts that the more efficient pattern would be to combine halogen and LED. The more efficient halogen bulbs for this purpose are PARs. PAR20 or PAR38 are best suited for these projects. Be sure to employ “Spot” instead of “Flood” for the beam width.  In addition to that, Bring up some bluest 6500k LED bulbs.

Sylvania 16743   70PAR38/HAL/S/NFL25 70w 1305lumen Medium 1500hrs  120v  5100cd  25° 2925k


It will need about double the brightness of halogen than LED to achieve a perfect natural white balance.

Let’s say in a closet like the first one, 6 halogen PAR would be needed (420 watts) and about 40-50 watts of LED Par as well in the 6500k part of the spectrum.

Osram 78551 seems to be a good product but not powerful enough, some more research would be needed.



Let’s talk safety. Since the whole machine will use and need to dissipate about 500 watts, if you keep all that heat inside, you’ll literally have an oven in which your veggies will be cooked before grown. Some ventilation will need to be taken in consideration as well as an over heating shut off protection system. Depending on the kind of veggies you want to grow, temperature must be set differently as well as the number of lighting hours.

I think it could be a great idea also to soft start the whole lightning in order to mimic the sunrise and sunset effect. I am not sure of that but I would pretend that instant blow of light under leaves that haven’t began yet to work on clorophyll could result into cell burns. Some experiment will have to be made on that as well.

I am planing on building the beta 4 version of my Heat & Grow machine soon. I just need a place to make it work where someone will have time to take care of it and add some daily water as needed.

In the 5th revision, an automatic water system will also be installed.

I may never sell a fridge to an Eskimo but who knows if I could sell them someday a Heat & Grow machine!