Hot Water Conversions NYC
There are still many one pipe steam, and two pipe steam systems in multifamily and commercial applications throughout NYC. With increasing energy costs and the consumer’s desire to be more comfortable there are opportunities to come up with a simple and cost effective method to convert a one pipe steam, or two pipe steam system to a two pipe circulating hot water system. Though, with enough money and determination anything is possible, the scope of work is great. A full steam to hot water conversion will impact on tenants and construction costs very greatly depending on the buildings size, location and construction type.
To learn what it would take to covert your steam system into a hot water- hydronic heating system contact the hot water conversion experts at HEAT.
Advantages of hot water compared to steam for heat distribution within commercial buildings are:
– Water temperature can be varied to suit variable loads.
– Hot water boilers typically do not require a licensed operating engineer.
– Heat loss from piping is less than steam systems because fluid temperatures are usually lower.
– Temperature control is easier and more stable because water temperature is matched to the load.
– Fewer piping accessories to maintain than steam systems.
– Reduced air stratification at light loads with reset hot water.
The control objectives for a hot water distribution system providing space heating are:
1. Provide adequate hot water flow to all heating units.
2. Maintain a stable pressure difference between supply and return mains at all load conditions.
3. Match hot water temperature to the heating load based on outdoor air temperature and/or occupancy.
a.Avoid heat exchanger flow velocities dropping into the laminar range.
b.Keep water velocities up to prevent freezing.
c.Reduce mixed air temperature stratification.
– No stratified cold air to trip low temperature controllers or cause freeze-up.
– Minimizes stratified air from having adverse effects on coil discharge temperature sensing.
– Minimizes possibilities of hot air flowing out some duct outlets and cold air flowing out others.
Hot Water Converters
A hot water converter uses either hot water or steam to raise the temperature of heating system water to a temperature which satisfies the heating requirements of the system. The most widely used hot water converters use steam.
Steam is often supplied to remote buildings or mechanical rooms from a central plant. Within the buildings or zones, hot water is often preferred because of its ease of control. Steam to water converters are used for these applications.
A converter consists of a shell and tubes. The water to be heated passes through the tubes. Steam or hot water circulates in the shell around the tubes. Heat transfers from the steam or hot water in the shell to the heating system water in the tubes.
If the pressure on the water in a converter drops below the vaporization pressure for the temperature of the water, the water can flash to steam. Pumps are usually located on the return side of the converter to provide a positive pressure and minimize flashing.