System Efficiency Improvements

Mr. Tuttle

Hello All,

I plan on having some work done on the two pipe steam system of our multi-unit residential building in downtown Boston. I just wanted to post my plan to help inform those less knowledge than me and to get the opinions of those more knowledgeable.



There are a few measures that jump right out at me such as insulating as much pipe as possible, repairing all steam traps, and installing TRVs on every radiator. I see a few less conventional measures as well though.



1. Replacing the current HX domestic hot water setup with a standalone, high efficiency water heater. As it is, the boiler has to run all summer just to keep the water tank at temp. Also, you'll notice all the discarded pumps. Something tells me this system never quite worked correctly (pic 3).

2. Changing the main supply piping. Right now the equalizer is coming off the side of the supply main (pic 2) so any carryover water has little chance of dripping down. I know it will be one of the more expensive measures, but I'd like to have it repiped the way it should have been: with the main line elbowed down to the equalizer and the supply main coming off the top.

3. Replace air vents with proper size. There are some that are completely blocked and others that are undersized and squirt. This will take a bit of calculation to properly balance.

4. Install sight glass. A nice little oversight of the initial installation. I think I'll install a water meter on the feed line as well, to keep track of the loss, depending on the cost.

5. Flushing out the system to remove 100 years worth of gunk. I'm not sure if there's any energy savings in it but it should be done as long as we're working on it. I'll have the low water cut off opened up and cleaned as well.



Please let me know your questions and suggestions.

Thanks in advance!

Rod

System Improvements

Hi- It sounds like you are going in the right direction.  You need to get a good steam pro to do the work for you as there are a lot of things that need to be reconfigured by someone who really knows what he is doing.

I don't know what you have for a control at the moment but I would look into a Tekmar or Heattimer control to run the system.as they can save a lot on the operating costs.

Properly tuned, a two pipe system can be really economical and comfortable.

- Rod

nicholas bonham-carter

improving system

spend the money first on pipe insulation, then reducing the pressure, and increasing the main [not rad] venting. with a good low-pressure gauge [gaugestore.com-0-2 psi], and a vaporstat you will start saving enough to pay for the re piping. you may need several hundred dollars worth of gorton #2 's. keep on adding them until you get the back-pressure during air escape down to an ounce or so. a good cleaning is also on that list as others have noted.

unless you can see a definite symptom with the piping, i would wait until summer to correct..--nbc

Mr. Tuttle

Project Update #1

Nicholas, Rod, I appreciate the feedback. The system does currently have a HeatTimer, but with no local control of temp (TRVs), it's not working as well as it could.

The pressure is turned down to 1 PSI, but I'll install a new guage that can more accurately measure lower pressures. That seems like a smart/cheap way to save a lot.



Recent troubles with the DHW heat exchanger have forced my hand a little and we did finally install a new dedicated DHW heater. It's a smaller, high efficiency, condensing heater, an AO Smith BTH-120. We cleaned out the old inefficient system and I think we're really going to see a lot of savings, especially in the Summer.



I'll post more updates in the coming months as more of the work is completed.