[an error occurred while processing this directive]
Posted by HeatPro on July 11, 2006 at 20:41:49:
In Reply to: Re: Calculating boiler size -- why variable estimates? posted by joe on July 11, 2006 at 16:49:46:
Yes, steam systems were designed before insulation was a thought, thermostats were invented, and work through their air vents to provide cycling rates.
The 'magic' thought that thermostats control everything can't over-ride the way steam systems work. Generally, they work at about 3 cycles per hour using the mass of the cast radiators to extend the heating time. So Joe's experience is the usual result.
Another problem is the installation of a modern standard of insulation in the home that has a steam system. What actually is the result is that an uninsulated house with the right amount of radiation and boiler in it suddenly becomes an insulated house with three times as much boiler and radiation than needed. A thermostat can't make up for that - but getting rid of 2/3 of the square feet of radiation helps ... but then you're stuck with a short-cycling boiler 3 times larger than needed. That story is what doing an estimate of the house with no insulation and then doing another estimate with the new insulation would tell you.