Heating Resin Printers During Winter

When it is warm outside the main concern with resin printing is ventilation. During winter we have to make sure the resin stays at an adequate temperature (usually 20°C+ for budget resin and 25°C+ for engineering resin).

A balanced option is to have the printer in a garage while not venting till after printing has finished. This keeps fumes outside the residence and provides the opportunity for efficient heating. A printer in the residence can be heated but heating air that is instantly vented is not efficient.

Our recommended method for heating resin during winter uses a grow tent enclosure, 500 W ceramic heater, and a temperature controller.

The 30x18x36" grow tent pictured is affordable and suitable for a single resin printer. It can barely fit multiple printers, so consider larger sizes if that is your plan.

The 500W ceramic heaters rapidly heat the entire enclosure. They can also be used to preheat resin in bottles.

The controller maintains a stable temperature with a sensor. The controller's sensor probe should be placed low and away from the heater.

Add-ons that can be useful are a hanging circulation fan and a timer power strip. The circulation fan promotes even heating, and the timer power strip will save energy by turning off all of the equipment after printing has concluded.

This simulation example demonstrates that a 250 W heat source, in combination with the cycling 45 W of the resin printer, can reach a maximum steady-state resin temperature of 35°C at 0°C ambient.

An efficient method to manage a 250 W heat source uses an inline controller. You will be able to place the controller within the enclosure and set your desired temperature.

The lower winter temperatures will lower the variance in the resin temperature. In this and the prior example, the target for the controller was 30°C. The prior example allowed the resin to rise ≈5°C above while this one is ≈1°C above.

The temperature-controlled heater will provide the best results to keep the resin at your desired target, but this method is more expensive to employ and uses more energy than the heating pads. Make sure that the controller you choose is rated for the power draw of the heater.

This thermal image showcases the temperature gradient of a printer when inside a grow tent with a ceramic heater. Heating the air of the enclosure provides a stable resin temperature, ensures that the build plate is warm, and heats multiple printers together.

We recommend preheating your resin before putting it into the vat in order to speed up the pre-flight check. The air temperature of the grow tent reaches 30°C in under 10 minutes, but the resin can take quite a while longer if left in the vat.

If you leave your resin in the vat, it can easily take 20-30 minutes to heat the resin to 20°C+ when the ambient temperature approaches freezing. When resin is preheated in a bottle in front of a ceramic heater, it should only take a few minutes.

This simulation demonstrates that a 250 W ceramic heater with no controller pointed directly at the printer will heat the resin towards 60°C. Beyond ruining the resin, this can damage electronics, warp plastic components, waste electricity, and start a fire.

This stresses the importance of a controller and properly positioning the equipment. The heater should not be pointed directly at the printer or sensor probe. Instead, the airflow should be parallel or away from the printer, and the printer should be on the opposite end of the enclosure.

This thermal image showcases the damaging heat that builds up within seconds when a ceramic heater is improperly positioned. The heater should be placed parallel to the printer.

With proper positioning, the enclosure can reach a stable temperature that is reliable for printing no matter how cold it is outside. A hanging circulation fan will assist in uniform heating.

A small heating pad is a safe and cheap method to raise the temperature of the resin during printing. Raising the temperature in a warmer environment can still be useful for engineering resins and reducing the exposure time on budget resin.

This simulation shows that at 20°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 33°C.

Resin at 20°C will take time to reach 33°C, or it can be preheated.

When temperatures begin to drop, even the 6.5 W heating pad will be able to adequately support budget resin.

This simulation shows that at 10°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 24°C.

The small heating pad becomes insufficient near-freezing temperatures. For a cold garage, an enclosure and a higher wattage heat source will be needed.

This simulation shows that at 0°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 15°C.

This thermal image shows that even after 15 minutes of operation, a small 6.5 W heat pad struggles to raise the resin temperature with an ambient temperature of ~12°C. 

This example stresses the importance of preheating the resin, ideally while it is in the bottle. The 500 W ceramic heaters excel at preheating the resin in bottles.

Another item of note is that any heat pad will not directly heat the build plate. If left cold when starting a print, the plate will chill the resin until it reaches equilibrium with the resin and the heat pad.

A grow tent enclosure provides only a minimal increase in the resin temperature during the warmer times of the year. However, it will aid in proper ventilation.

This simulation shows that at 20°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 34°C, while in a grow tent.

When temperatures begin to drop, the added insulation of the enclosure becomes apparent. There is a ≈1°C increase in the resin.

This simulation shows that at 10°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 25°C, while in a grow tent.

At freezing temperatures, the enclosure will bump the resin temperature up by ≈2°C, but the ≈17°C resin is still below the recommended levels. The resin can print at this temperature but the exposure times and risk of failure will be higher.

This simulation shows that at 0°C ambient, a small 6.5 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 17°C, while in a grow tent.

The resin in this thermal image was preheated to ~20°C. This showcases the inconsistent resin temperature when heating with a small heat pad or band. 

A temperature gradient forms within the resin, resulting in cold pockets. While this won't necessarily cause any problems from a top-level perspective, the varying resin temperature will have differing exposures, which can affect the print locally.

As stated earlier, a vat heat pad will not directly heat the build plate. Instead, while printing, the cold build plate will dip into warm resin, chilling the resin with each layer. 

Swapping a small 6.5 W heat pad for a larger 18 W variant will keep budget resin in its recommended range.

This heating pad can be attached to the interior or exterior of the acrylic cover, with the interior being more efficient. You can use various attachment methods such as kapton tape, nylon string, or zip ties so long as the pad is not punctured.

This simulation shows that at 0°C ambient, a large 18 W heat pad and the cycling 45 W of the printer can heat the resin to a maximum temperature of 20°C, while in a grow tent.