Case Study: Local Restaurant Needs Hot Water
What’s the deal with pressure? One of the common things our service dept receives are calls regarding pressure. Meaning how much “pressure” the propane tank can provide. If a propane system hasn’t been “sized” properly, you can experience appliance issues.
Gas line sizing, distance, appliance load and regulator setup determine propane pressure capabilities. Calculations are used to determine the correct setup. In many cases, a propane system had been installed many years before, and changes have been made that can affect the system.
In this case, we received a call from a restaurant who had added a new on-demand hot water heater, this replaced a standard tank style heater. The On-Demand heaters have a much higher BTU load**. The restaurant has been in service with other commercial appliances (Comm ranges, flat top grills, broilers etc) that worked fine until this new water heater was installed.
The issue: My appliances keep going out when the new water heater runs.
*British Thermal Unit- Brit·ish ther·mal u·nit
noun: British thermal unit, plural noun: British thermal units. (The amount of heat needed to raise one pound of water at maximum density through one degree Fahrenheit, equivalent to 1.055 × 103 joules.)
The customer’s temporary fix was to use propane bottles near the water heater. This is not ideal, and also requires the interruption of service often. The best case is to have this water heater plumbed within the piping for the whole building.
Once the piping was located, We were able to determine the sizing of the incoming pipe to the restaurant, and assure that all lines needing service were available in this location. We discovered that the pipe sizing is adequate, but the regulator system would need to be changed to accommodate the increased need of the new on-demand hot water heater.
The fix-Currently the system runs on a low-pressure system. To increase the pressure, you do this through regulators. Right now, the regulator supplying the service is many feet away from where the need is required. This can be changed by changing around the regulator setup, from a high to a low-pressure system. Also known as a two-stage system. The first regulator delivers high-pressure fuel through the underground piping to the building, a second stage regulator then drops the pressure to the required pressure for the appliance, (generally 11-13” of water column). When this is done, you have essentially tricked the system into thinking the tank supply is much closer to the need.