Taken from https://ccctrustroofproj.wordpress.com/
Phase II of the Cambridge Cooperative Club Trust’s “Big Roof Project” is the replacement of three old heating systems and one hot water heater with a single super-efficient heat system for both space heat and hot water.
This part of the project is happening before the roof because by eliminating the old fashioned boilers, we will no longer need the chimneys. The new system will vent to the side of the house. The chimneys can be cut off at the top of the house. When the new roof goes on, there will be no penetration at the chimneys. This will reduce the amount of heat leaving through such holes in the top of the house, and also reduce the amount of possible future leaks by making the roof more of a single sheet of membrane.
As you can recall, we wanted to put solar panels on the roof. This has led to all these related components – the structural work, the heat plant, re-engineering the roof structure as well. Eventually we’ll have solar panels.
For the heat system, we used Village Plumbing of Westport Mass.
Here are some pictures of the project:
This is one of the three old boilers to be replaced.
We took out a lot of the old steam piping, some of which has since been turned into hot water circulation to the old radiators. Also, a lot of gas pipes to the different heating systems. On a cold winter’s night we used to have four different fires burning in the basement!
We are using a Buderus Logomax Plus. It’s an incredibly efficient device. It will supply heated fluid to all the radiators and the heat-exchanger at the instant hot water heater. The temperature is set with a thermostat to the outside temperature, so, depending on our preferences, when it is cold out, the system will kick on, but based on the more slowly fluctuating outdoor temp than the internal temperature of the house. This will smooth out the requirements so there are fewer spikes in demand which, just like rapidly accelerating in your car, cause the most inefficient energy transfer.
Here is the dismantling of the old radiators and re-configuring to utilize the new system. The cast iron of the radiators is good for thermal mass and enabling the temperatures to remain more constant and the distribution to be smoother.
Each unit has a small thermostatic controller – depending on the set temperature determined at the Buderus, the circulation fluid (a closed circuit of water) is delivered to the radiators. Each housemate can open or constrian the delivery at their own radiator. No more thermostats, each room is essentially its own zone, based on the heat plant in the basement.