Time for Toyotomi L730 to go to Positive Pressure

[hawkins111]

Toyotomi just announced there new Laser 734 heater. About the only thing new is that this unit has a BlueTooth function.

All other models of the Toyotomi Laser line today, have gone to a "positive pressure " model. This means that "no" exhaust touches the fan. The combustion fan pushes all the air through the heater and out the exhaust. No combustion byproducts touch any fan.

The older Toyos (Laser 56, L73) were what we call "negative pressure units". They had two fans on a common shaft. One provided combustion air to the burner and the other sucked exhaust products out of the burner chamber and heat exchanger. Of course, the exhaust that passed by the fan would get it covered with soot over time. This reduced the service time because the fan needed to be cleaned and in worst cases caused the blower motor to get out of balance and destroy the motor.

I do not understand Toyotomi's insistence in keeping the L730 line a "negative pressure" unit. In days gone by Monitor had 40K BTU units. They seemed to function OK, even though they had their own different problems.

In the early days there was a thought process discussed around the Toyostove business that you could not make a 40K BTU unit run right as a positive pressure unit. That idea was put to bed by Monitor 441 and M2400, both of which functioned fine.

It's long over due for Toyotomi to upgrade their 40K BTU units to a positive pressure design.

Tom

[machinist]

Interesting points, Tom. Perhaps there are manufacturing cost considerations or patent issues we're not aware of? Or maybe they're concerned about compatibility with existing installations? Still, with just BlueTooth being added to the 734, it seems like a missed opportunity to address these fundamental design limitations.

[Tomhanks]

One reason could be that they've invested heavily in their current manufacturing setup, and switching to positive pressure would mean retooling their entire production line.

[hawkins111]

In 1999 Toyotomi introduced a new stove that was meant to fill a smaller nitch in the market. That was the 13K BTU Laser 30 heater. It was a positive pressure unit. At that time this Laser 30 was the only positive pressure unit in the whole Toyotomi line.

In 2002 Toyotomi introduced the Oil Miser 22 heater. This heater had the same spec. as their Laser 56 heater, 20K BTU's. The
OM 22 was a positive pressure unit. This heater line was produced along side the negative pressure Laser 56 all the way to about 2016.

Toyotomi changed their 13K and 20K Positive Pressure units in about 2017 to the present day Line of Laser 300 and Laser 530 heaters. The Laser 56 changed to Laser 560 and continued as a negative pressure unit. The Laser 560 only lasted for two or three years and was then dropped from the line.

In about 2017 the Laser 73 changed to Laser 730 and continued as a negative pressure unit. In my opinion, this would have been the time to change to a Positive Pressure. Granted, the L730 cabinet and internal parts are the same as the older L73. The thing that changed was all the electrical. Because there were additional electrical circuits added to the L730 burner, it would need to go through another process during manufacturing. Again, this would have been the time to change the whole unit.

I do not see any Patent issues that Toyotomi would have offering a Positive Pressure heater in the 40K BTU range. Patents only last 20 years and it have been longer than that since Hitachi built the Monitor heater line.

This whole issue baffles me to no end.

Tom