If you're looking ahead to winter and considering a boiler replacement, choosing a boiler for a steam heating system requires the careful consideration of sizing and installation. Steam heat differs greatly from hydronic heating, where the pipes circulate hot water.
A steam system converts water into steam in the boiler, then conveys that hot steam through pipes to radiators. Steam condenses in the radiator, releasing latent heat that's radiated into rooms. The major consideration when sizing a new boiler to an existing steam system is that the boiler must provide the same capacity of steam as the total condensing capacity of all radiators the new boiler will be connected to.
An HVAC contractor will perform a sizing assessment by determining the equivalent direct radiation (EDR) ratings of every radiator in the system as well as adding in a compensation, known as a pick-up factor, for heat loss from interconnecting pipes. When these are totaled, your contractor will make a calculation that tells him or her the exact boiler size required to fill all radiators with steam.
The consequences of an undersized boiler are obvious: uneven and/or insufficient heating throughout the system. However, upgrading to a boiler with too much capacity also produces undesirable results, as it forces too much steam into the system. Water spurts from steam vents, water hammering in the pipes creates alarming noise and the boiler short cycles, turning on and off repeatedly, wasting energy.
After choosing a boiler, proper installation involves an evaluation of the existing system it will be connected to, including the following:
- The condition of piping above and below the water line of the boiler. Iron pipe, instead of copper, is the standard for conveying steam throughout the system.
- The condition of insulation on all pipes and the proper operation of steam vents.
- The proper function of the vent connection pipe and the existing ventilation chimney.
- Correct adjustment of all boiler controls to produce optimum steam temperatures for maximum boiler efficiency.
For more advice about choosing a boiler for your steam heating system, contact the pros at P.K. Wadsworth. We're happy to serve homeowners in and around the Cleveland area.
Paul Wadsworth is the President and Owner of P.K. Wadsworth Heating and Cooling. For 37 years, Paul has been providing heating and cooling services to the Greater Cleveland area. P.K. Wadsworth has been a trusted Cleveland HVAC service company for over 75 years. The company understand the area's construction and local heating and air conditioning needs. Paul has an MBA from the University of Michigan and a B.S., Industrial Engineering from Purdue University. Paul is the Chairman of COSE's Energy Advisory Council. He's been President of the Cleveland Air Conditioning Contractors of America and a founding member of the local chapter. Paul was born and raised in Cleveland and has been active in the local community. He resides in Cleveland, Ohio with his wife and two sons.
The opinions and statements contained in this article are for general informational purposes only and are not instructions. Only trained, licensed and experienced personnel should attempt installation/repair. The author assumes no liability for the opinions/statements made in this article. Any individual attempting a repair or installation based on this article does so at their own risk of loss.