How to meter the hot water from a boiler

Question

I have a 3 multi unit place, but there is only one boiler & oil tank. Heat is supplied by forced hot water. Each unit has its on zone, and each zone has an electrical meter that is monitoring how long the circulators run for. Theoretically I would think I could proportion those numbers to correspond to a % usage, and then I could charge them that % of the oil bill. Currently I pay the oil, which is not my preference for obvious reasons. Has anyone had a any experience with trying to monitor water usage like this. Or do they have a better idea of how I should meter the usage, like maybe an actual flow meter on the hot water side?

Thanks

Florian N. · Answer

@Mark Cherv Michael is probably talking about mini-split systems: http://www.fujitsugeneral.com/us/residential/what-is-a-mini-split.html

Mark Cherv · Answer

Hmm, interesting.   They are certainly zoned correctly.  Admittedly that would monitor the baseboard heat, and would not account for sink, shower, etc.   What are these mini heat pumps you speak of?

Michael Totman · Answer

Check the local laws, utilities tend to be looked at closely in landlord/tenant situations. Here to your south that would be illegal with only one oil tank/boiler I believe; how do tenants know that the oil THEY paid for was the oil burned during the time you charged them if both units were calling for heat?   But if they are zoned correctly it shouldn't be too much, relatively speaking, to add two more systems or even check into newer minisplit heat pumps that work down to negative temps that don't require complicated new pipes/duct work through the walls.  I did this recently at less cost than a new boiler, and the added marketability of the included air conditioning is great.