Need to meter heat zones

Joe_8

I would appreciate any help on this. I have a client that has two tenants sharing one boiler. I know that I can meter the flow on each zone to help divide the fuel bill, but has anyone ever heard of a device that would record the time that each circulator runs (electric usage) and compute that into a percentage of the total. If there is not such a device, then there should be. Thanks for your help.

dconnors

hour run meter

you need an hour run meter. you need to put one on each zone then bill by the percentage of the total. Kinda expensive to use a btu meter. i would rather go with an inexpensive hour run meter.

Jay_12

BTU meter

What you are looking for is a BTU meter. It requires a flow meter and two temperature sensors - one on the supply and one on the return to measure the temperature difference (dT). The controller multiplies the flow by the temperature difference to calculate the number of BTUs. Then you need to determine the cost per BTU for the billing. This device does exist but I forget who manufactures it.

Jay

Bob Knebel

ISTA BTU Meter

Hello,

We obtained BTU meters in the past from ISTA Energy Systems Corporation in Roselle NJ (908) 241-8880. It has been awhile so I'm not sure if they are still at that location and phone number. Very precision piece of equipment. Can also get nice totalizing domestic hot water meters if you want to separate out DHW usage in apartments off of one big indirect DHW production tank (or group of tanks). Hope the info is helpful.

Bob Knebel / Radiant Engineering, Inc.

Brad White_2

Strictly legally speaking

the hour run or even flow total method can be challenged in court. (Even if parties agree, these days what does that matter?) You do need to measure both flow and temperature over time to be equitable.

For example if one tenant/user takes 4 gpm and the other also takes 4 gpm and keeps the same hours, the run time would be the same. But if one sends the water back 20 degrees cooler than supplied, and the other sends it back only 10 degrees cooler, they have used half as much heat. Can you imagine years later the litigation if things go sour?

Brad White_2

ISTA

I second the motion. Good, simple equipment and sold as a system (meter, totalizer and sensors).