University Place HVAC Frequently Asked Questions
I have been asked several questions, and seen several work orders regarding the heating, ventilating, and air conditioning at University Place Apartments, and there appear to be some misconceptions as to how the system works. Hopefully this will clear some of those questions up.
- Why can’t I choose between heat and air conditioning myself? / Why do my vents blow cold air when I want heat or vise versa?
The system here is what is known as a two-pipe system. We have boilers that create hot water for heat in the winter, and chillers that create cold water for A/C. This water is then circulated througout the building to the unit in the kitchen ceiling, known as a fan coil. This is a coil not unlike a car’s radiator, where air is blown (by the fan) past the coil, to transfer the heat into or out of the coil. The thermostat controls the fan. Since there are only two pipes (supply and return), that means we can only run the chillers or the boilers, not both. This is why you see signs saying “The heat is on”, etc. We have to physically switch from one to the other by changing valves around. Some newer buildings that have central heating and cooling equipment like this use a “4-pipe system” where there are two seperate systems and two seperate coils in the fan coil units, and you can choose which you want. When this building was built in 1964, 4-pipe systems were not common, and were VERY expensive.
- OK, so why don’t I always get heat (or A/C) when the system is in that mode?
This likely has to do with the outside temperature. The boilers and chillers are computer controlled, and if the temperature outside is too high (heat) or too low (A/C), the BMS computer will automatically shut the system down. Currently, if it’s warmer than 50 degrees ferinheight (10 degrees celsius), the boilers will shut off, and will turn back on when it drops below 48F (~9 C). When the chillers are running, if it drops below 54F (~12 C), the chillers will shut down, and they will start when the temperature rises above 58F (~14.5 C). You can see if the central system is running by checking the marquee by the double doors in the lobby, the package screen by the offices, or the package page under “Residents” on our website.
- The thermostat keeps saying “Change Batteries”… Why?
The thermostats actually don’t have batteries in them (they can, if they’re needed). The controls in the fan coil unit actually provide power for the thermostats, and they’re not smart enough to realize that they’re being supplied external power, and complain about batteries. This is the one thing I don’t like about these thermostats… As long as your thermostat has a display and is working, you can safely disregard that message.
- The exhaust fan in my bathroom isn’t working. Shouldn’t it come on with the light?
No. The exhaust fans are computer controlled as well, and are set to come on for 15 minutes every hour. Currently, they’re on from the top of the hour to quarter-past on the main wing (apartments x01 to X28), and quarter-past to half-past on the east wing (apartments x29 to x44). They may be turned on at other periods depending on what the maintainence staff is doing. (If they’re epoxying a shower, for example, we’ll turn the fan on) Note: Each fan handles 8 apartments, and for humidity control, it’s important that the bathroom door is left open to ensure even airflow from all 8.
If you have any other questions, feel free to drop by the office or email me at bwilmot at uplace dot com .
Building Systems Engineer