logo for print

Evaporator Heater for Vending Enclosure

We have a customer that makes air conditioners for product vending enclosures. These A/C units drip water. When evaporation doesn't happen quickly enough the drip tray overflows and the enclosure leaks water on the floor. This project had many tough requirements and no takers. Tutco-Farnam stepped up to the challenge.

Project and Challenges

The intention of the heater is to expedite the evaporation of condensate in the drip tray, preventing an overflow of water. This project required a heater (including the entire assembly) that would fit into a very tight location within the tray.

The heater will be sitting in water and needs to be submersible, which also means we can’t use any fiberglass in our silicone. The drip tray is not always filled with water though. When empty the evaporator heater is going to get very hot. Some method of temperature regulation would be required. Because of the small space, there is no room for a sensor to tie back into the control system. We couldn’t even put a thermocouple for feedback.

Solutions and Their Impact

Tutco-Farnam came back to the client with a custom flexible waterproof heater. We bonded raw silicone rubber (no fiberglass) and sealed the edges to ensure it is submersible. We put a PTC thermistor on the surface of the heater with a cut-off switching temperature and PSA on the bottom for easy installation.

Now we’ve got a small self-regulating silicone rubber heater that will switch itself off if it gets too hot. Our heater fits into a tiny space and helps the water to evaporate fast. In the field, a technician is easily able to install the heater. No more water running on the floor and the heater never gets too hot.

Related Content


  • Powerful Heater / Small Package
  • Waterproof
  • Self Regulating
  • Easy to install
  • No controller required
A HIGHER °DEGREE 8.8 2.4 1.5 12.5 16.2 of Support Find Out More

Engineering service and support is a big part of what we do. Offered on an application by application basis. With over 2,000 unique heating element designs, chances are we have done something similar to your project.

Engineering Questions Answered

    Question: How do I prevent the drip tray from overflowing?

    Solution: One possibility is to use a submersible silicone rubber heater. This means no fiberglass in the silicone and the edges must be sealed. Either tie that back to a controller or include a thermistor. We have been successful piggybacking a PTC to the silicone.

Feel free to Contact Us and tell us about your heating needs.
Calculators +
Menu +