dbarufaldi
New Member
Hi all:
I have a three family house that is currently heated with a 1940 (!) Janitrol gas-fired hot water boiler. Most of the house has radiators, but there are a few baseboards and convectors. The house is divided into three discreet spaces, but has only one thermostat and zone. It is a woodframe house that is connected on both sides to other woodframe houses (brick firewalls on each side). I don't have heat loss numbers, but I know that the two side walls join heated space of the adjoining house. The basement is unheated except for heat loss from the boiler and pipes. I currently pay for all gas and water, so heat and hot water are my responsibility. Also, in NYC, there are very strict laws about temperatures between Oct and May, so most buildings are overheated to be sure the coldest rooms meet the standard. Not perfect, but there you have it. The fuel costs are pretty substantial with the existing system.
Ideally, I would like to convert to a system that allows me to have each apartment pay their own heat and hot water. So far, the only system for this that I have found is to put in three separate boilers, and replumb the radiators/baseboards by zone. Two apartments would have one zone each, and one apartment would have two. In addition, I would like each boiler to have the additional "zone" for hot water, in an integrated system (heat and hot water) with storage tank. I would also consider going with tankless water heaters, but after initial research, I think the demand would be such that the integrated boiler would be more efficient. I also want to go as high efficiency as I can afford, so I think modulating/condensor boilers may be the answer. I will have to re-route the exhaust, as I currently have a single-flue brick chimney that would not support three flues.
So here are the questions...
- Any other practical way to split the heat out? I know I could take the bill and divide it by square footage, and retroactively bill each unit, but without tenants having the ability to control their own usage, that gets prickly. Just building it into the rent means that the rent has to fluctuate with energy prices, or I price myself pretty high to leave a cushion.
- I am trying to come to an ROI (return on investment) calculation for just upgrading the boiler to something more efficient. I know how to do the calculation once I have an estimated cost of usage post-conversion, but how do I come up with that number? I could probably back into it if I knew the general efficiency of the 70yr old boiler, without a flue damper.
- If I do the entire 3-boiler system, the prices are around $30K, including professional asbestos abatement and followup air testing, upgrading gas supply to boiler room (there is sufficient supply to the house), additional meters, etc. These was heat only, not the integrated hot water. I assume the added integration would be another $5-$7K. That ROI calculation is easy enough because I would have no fuel costs. Total conversion cost, divided by annual fuel costs saved = number of years to break even.
- Given the above, any other things I should be thinking about (aside from the obvious, like insulation, windows, etc, which I am already addressing).
Dan B
I have a three family house that is currently heated with a 1940 (!) Janitrol gas-fired hot water boiler. Most of the house has radiators, but there are a few baseboards and convectors. The house is divided into three discreet spaces, but has only one thermostat and zone. It is a woodframe house that is connected on both sides to other woodframe houses (brick firewalls on each side). I don't have heat loss numbers, but I know that the two side walls join heated space of the adjoining house. The basement is unheated except for heat loss from the boiler and pipes. I currently pay for all gas and water, so heat and hot water are my responsibility. Also, in NYC, there are very strict laws about temperatures between Oct and May, so most buildings are overheated to be sure the coldest rooms meet the standard. Not perfect, but there you have it. The fuel costs are pretty substantial with the existing system.
Ideally, I would like to convert to a system that allows me to have each apartment pay their own heat and hot water. So far, the only system for this that I have found is to put in three separate boilers, and replumb the radiators/baseboards by zone. Two apartments would have one zone each, and one apartment would have two. In addition, I would like each boiler to have the additional "zone" for hot water, in an integrated system (heat and hot water) with storage tank. I would also consider going with tankless water heaters, but after initial research, I think the demand would be such that the integrated boiler would be more efficient. I also want to go as high efficiency as I can afford, so I think modulating/condensor boilers may be the answer. I will have to re-route the exhaust, as I currently have a single-flue brick chimney that would not support three flues.
So here are the questions...
- Any other practical way to split the heat out? I know I could take the bill and divide it by square footage, and retroactively bill each unit, but without tenants having the ability to control their own usage, that gets prickly. Just building it into the rent means that the rent has to fluctuate with energy prices, or I price myself pretty high to leave a cushion.
- I am trying to come to an ROI (return on investment) calculation for just upgrading the boiler to something more efficient. I know how to do the calculation once I have an estimated cost of usage post-conversion, but how do I come up with that number? I could probably back into it if I knew the general efficiency of the 70yr old boiler, without a flue damper.
- If I do the entire 3-boiler system, the prices are around $30K, including professional asbestos abatement and followup air testing, upgrading gas supply to boiler room (there is sufficient supply to the house), additional meters, etc. These was heat only, not the integrated hot water. I assume the added integration would be another $5-$7K. That ROI calculation is easy enough because I would have no fuel costs. Total conversion cost, divided by annual fuel costs saved = number of years to break even.
- Given the above, any other things I should be thinking about (aside from the obvious, like insulation, windows, etc, which I am already addressing).
Dan B