Radiator Heat
Some buildings are heated by Radiators. If your building has radiated heat, please read the following information to determine how the system works, and what to do if you have problems.
Radiated heat is automatically supplied to the system in accordance with outside air temperature. To maintain comfortable conditions, heating is typically provided from October 15th through April 15th, but it may be started and ended earlier or later as weather dictates. As an energy conservation measure, the temperature of the system is reduced slightly during nighttime hours.
Heat is always kept at a constant average temperature. Because heat rises, lower levels of your radiated heat building will be a bit colder than average, and upper floors will be a bit warmer than average.
Seasonal Preparation
If the radiator system in your building is about to be activated, please take the following steps to prepare:
- Clean the radiators. Make sure dust and dirt have been cleaned from all radiators, especially in the grill spaces. Dirt and dust absorb heat, and can heat up creating burning smells and triggering dust allergies.
- Remove all items from the radiators. Make sure all items that might be leaning on or set on top of the radiators and heat pipes are removed. They may be damaged by the heat.
- Clear space around the radiators. For your own safety and the safety of your belongings, we recommend you keep clear a three foot radius around the radiator at all times. It is critical to keep all items that may be affected or ruined by heat well away from the radiators and any other heating elements such as heat pipes.
About Radiator Systems
There are two types of radiators - hot-water and steam. You will need to know which type of radiator your unit has in order to know how to properly operate it. To find out which type, take a look at the radiator.
- Steam Radiators can have either one or two pipes leading to them. If it has one pipe, it is definitely a steam radiator. Sometimes steam radiators have two pipes, so make sure to check for other indicators as well. If the radiator says STEAM on the side, or if it has a steam vent on the side (usually bell shaped - see picture below), it is a steam radiator.
- Hot-Water Radiators always have two pipes leading to it. If it has two pipes leading to it, and it has a bleed valve (see picture to the right - bleed valve is on the side at the top), it's a water radiator.
Some information in the following sections has been taken from Energy.gov.
Steam Radiators
Steam heating is one of the oldest heating technologies, but the process of boiling and condensing water is inherently less efficient than more modern systems, plus it typically suffers from significant lag times between the boiler turning on and the heat arriving in the radiators. As a result, steam systems make it difficult to implement control strategies such as a night setback system. This means that they take a while to heat up, and then they take a while to cool down, so they are not as effective until the weather is consistently cold during both the day and the nighttime.
Maintenance
Regular maintenance for steam radiators depends on whether the radiator is a one-pipe system (the pipe that supplies steam also returns condensate) or a two-pipe system (a separate pipe returns condensate). One-pipe systems use automatic air vents on each radiator, which bleed air as steam fills the system and then shut automatically when steam reaches the vent. A clogged air vent will keep a steam radiator from heating up. Air vents can sometimes be cleaned by boiling them in a water and vinegar solution. If that does not work, you should contact maintenance to request replacements.
Radiators should be kept clean since dirt and dust absorb heat. Also, dust and dirt can heat up and create burning smells and trigger dust allergies.
Banging
Steam radiators can also warp the floor they are sitting on and their thermal expansion and contraction over time can dig ruts into the floor. Both of these effects can cause the radiator to tilt, preventing water from properly draining from the radiator when it cools. This will cause banging noises when the radiator is heating up. If your radiator bangs, you can contact maintenance for assistance. They will insert shims under the radiators to pitch them slightly toward the steam pipe.
Efficiency and Loss of Heat
Steam radiators located on exterior walls can cause heat loss by radiating heat through the wall to the outdoors. To prevent such heat loss, you can install heat reflectors behind these radiators. You can make your own reflector from foil-covered cardboard, available from many building supply stores, or by mounting foil onto a foam board or other similar insulating surface. The foil should face away from the wall, and the reflector should be the same size or slightly larger than the radiator. Periodically clean the reflectors to maintain maximum heat reflection.
Shut-Off Valves
Never, ever adjust the shut off valve! It must remain fully open at all times! Attached to the pipe leading to the radiator is a valve. This is a shut-off valve. It is meant to shut off the radiator for maintenace purposes. That is the only use for this valve. People often assume that they can control how hot the radiator is by turning the knob on the shut-off valve. Unfortunately, this is the worst thing you could do in a steam heating system. If you adjust the valve, you will force the steam and the water in the radiator together, which creates boiling water. The agitated water will then dance in the metal radiators and pipes, making loud banging noises. Adjusting the shut off valve can also create a heating imbalance in the entire building.
If the shut-off valve is closed, please do not attempt to open it yourself. Incorrect adjustment may cause damage to the system. Instead, contact maintenance for further assistance.
Air Vents
On the opposite end of the radiator, there is an air vent (see picture). This vent should always be standing straight up with the vent hole at the top. These come in a few different varieties, most look like a bell, but they all serve one purpose - they let the air out of the radiator, making way for the steam to come in. With some vents, you can use a screwdriver, coin or something flat to turn or twist the notched area at the top of the vent – this controls the amount of air in the radiator. The basic premise is that if you control the amount of air that comes out of the vent, you control how much steam goes in, thus limiting how hot the radiator gets. Please note that if you open or close the vent hole, you need to be patient for a change in heat to occur.
Vents hiss and whistle, sometimes loudly. This is normal.
Air vents must be kept free of dirt, paint, clothing etc. for the radiator to operate efficiently because if the vent hole is covered, the vent stops venting and the radiator will stop working.
Hot-Water Radiators
Hot-water radiators are one of the most common heat distribution systems, second only to forced-air systems. They are typically a baseboard-type radiator or an upright design that resembles steam radiators (more common in older buildings). Hot-water radiators work by heating water to a pre-set temperature in a basement furnace, and then circulating that water from the furnace through daisy-chained radiators. Hot water will flow in one side of each radiator, and out the other side to the next radiator in the chain (see diagram). Once the water reaches the last radiator, it is then sent back to the furnace to be reheated.
Maintenance
Radiators should be kept clean since dirt and dust absorb heat. Also, dust and dirt can heat up and create burning smells and trigger dust allergies.
Bleeding
The most common problem in hot-water systems is unwanted air in the system. If your radiator is hot at the bottom but not at the top, or if the system is on but the radiator is completely cold, there is probably air trapped in it preventing hot water from filling it up completely. In tis case, the radiator will need to be bled. You should always keep a radiator key in your apartment (see picture) to bleed radiators when necessary. If you don't have a radiator key, submit a maintenance request and we will provide one to you at no cost.
To bleed the radiator, place a cup under the radiator valve to catch any water that might squirt out. Then insert the key and turn it, opening the valve. You will hear a hissing sound. Keep the valve open until either water squirts out, or the hissing stops. If water squirts out, quickly close the valve. The radiator is bled and will now work properly. If the hissing stops but no water squirts out, close the valve and wait an hour for the system to regain pressure. Then try again. Keep trying until water finally squirts out.
Efficiency and Loss of Heat
Hot-water radiators located on exterior walls can cause heat loss by radiating heat through the wall to the outdoors. To prevent such heat loss, you can install heat reflectors behind these radiators. You can make your own reflector from foil-covered cardboard, available from many building supply stores, or by mounting foil onto a foam board or other similar insulating surface. The foil should face away from the wall, and the reflector should be the same size or slightly larger than the radiator. Periodically clean the reflectors to maintain maximum heat reflection.
Shut-Off Valves
Never, ever adjust the shut off valve! It must remain fully open at all times! Attached to the pipe leading to the radiator is a valve. This is a shut-off valve. It is meant to shut off the radiator for maintenace purposes. That is the only use for this valve. Since hot-water systems require water to both enter and leave each radiator before moving on, adjusting the shut off valve can create a heating imbalance in the entire building by restricting hot water flow to consecutive radiators.
If the shut-off valve is closed, please do not attempt to open it yourself. Incorrect adjustment may cause damage to the system. Instead, contact maintenance for further assistance.
Requesting Maintenance
Many radiator issues can be solved by following the advice above. Here are the conditions when you should request maintenance on your radiators:
- In a steam system, if the pipes or radiators are banging or knocking (this means that the water and steam are running together and restricting the flow of steam). Sometimes banging can't be resolved, but an attempt will be made.
- If the shut off valve is closed.
- If the radiator is wobbly.
- If the radiator or pipes are leaking water.
- If the radiator is cold, but the shut-off valve is open, and (for steam) the air vent is clear or (for water) the air has been bled.
