Precision, programmable temperature control – Select a temperature and get it! (Download Fan Coil PDF File) The T9000 wireless thermostat is the most flexible thermostat solution on the market today. Battery operated, the thermostat uses a 916.5MHz RF transceiver to send and receive control information to one or more Receiver Control Nodes (RCN). The system is unique in that it is capable of simultaneous control of completely unrelated, multiple heating and cooling HVAC loads through one thermostat, creating a virtual central heating and cooling control system. The T9000 provides precision wireless thermostat control capability to a wide range of Fan Coil Unit (FCU) applications. Configurations are available for the simplest and the most complex control situations: 2-pipe fan, fan/valve control 2-pipe with auxiliary heat. 4-pipe single-stage, two-stage air conditioning Fan coils are common air conditioning systems used in commercial and residential buildings.

In its simplest form, a central plant delivers hot or cold water to fan coil units, typically located on a perimeter wall in the space to be heated or cooled. A fan draws air from the room, blows it over the heated or cooled water-to-air heat exchanger, (coil) and returns it to the room. 2-pipe FCU systems use a single heating/cooling coil, with supply water seasonally changed from hot to chilled water. A 4-pipe FCU has separate heating and cooling coils. Provided the central plant supplies both heated and chilled water, a 4-pipe system allows year-round heating, cooling, and dehumidification. 2-pipe systems are common, particularly in residential multifamily applications and older buildings. Fan coil controls can be as simple as just cycling the fan with or without a flow valve, or more complicated with separate heating and cooling valves, auxiliary electric heating elements, DX coils, and multiple fan speeds. Simple to understand user interface controls. Styling for home, office, or hotel applications.

Digital display of ambient temperature, and user setpoint temperature. Easy pushbutton adjustment of all functions.heat pump unit making noise Accommodates external energy management inputs such as occupancy sensors and switches.ac outside unit not spinning Battery powered, no control wiring needed.fan coil unit support Adjustable maximum heating and minimum cooling setpoint limits. Direct load control potential. Packaged Terminal Air Conditioner Packaged Terminal Heat Pump More Information on Fan Coil Unit… No heat pump system is complete without the fan coil. Payne® fan coils are a perfect match with any of our heat pumps to deliver quiet, energy-efficient comfort. Whether you need a more traditional model or one that fits unique needs like wall or ceiling installation, you can count on Payne fan coils for exceptional heat transfer, heating and cooling effectiveness and efficiency.

Alex and Jerelyn Wilson heat their two-story Vermont home with a single ductless minisplit unit. The minisplit head (a fan-coil unit) is located on their kitchen wall. has endeavored to publish reports from the field to guide people designing homes that are heated and cooled by ductless minisplits. We’ve learned a lot on this topic since 2008. My article on Carter Scott’s approach to heating and cooling was called “Just Two Minisplits Heat and Cool the Whole House.” Since that article was published, builders, engineers, and researchers have shared their minisplit experience and data. Carter Scott has given technical presentations at several conferences (including the Westford Symposium on Building Science and NESEA’s BuildingEnergy conference); energy consultant Marc Rosenbaum has written several valuable articles on the topic for GBA (including “Minisplit Heat Pumps and Zero-Net-Energy Homes” and “Practical Design Advice for Zero-Net-Energy Homes”); and researchers Kohta Ueno and Honorata Loomis have published useful monitoring data (“Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast”).

We now have enough information on the use of ductless minisplits to heat and cool cold-climate homes to set out some rules of thumb. The nine rules of thumb that I present below are based on the work of Scott, Rosenbaum, Ueno, and Loomis, to whom I am indebted. If you want to heat and cool your building with just one or two point-source heaters, you want an above-average thermal envelope. That means that the building needs a very low rate of air leakage; above-code levels of insulation; How To Buy a Ductless Minisplit Minisplit Heat Pumps and Zero-Net-Energy Homes Practical Design Advice for Zero-Net-Energy Homes Report on Our Ductless Minisplit Heat Pump Long-Term Monitoring of Mini-Split Ductless Heat Pumps in the Northeast If you live in snow country, your outdoor unit needs to be protected by a roof — but not a roof that inhibits air flow — or needs to be wall-mounted at least 4 or 5 feet above grade. It’s better to locate the outdoor unit on the gable end of a house than under the eaves.

A single ductless minisplit unit located on the first floor of a two-story house is often capable of heating the whole house. However, a first-floor unit is incapable of cooling the upper floor. In a two-story house, if you want both heating and cooling, you will need at least two ductless minisplits: one downstairs and one upstairs. The downstairs unit will do most of the heating, and the upstairs unit will do most of the cooling. If you are heating your house with one or two point-source heaters, it’s a good idea to avoid oversized windows if you want to minimize room-to-room temperature differences. The temperature in a bedroom can be within 4 F° or 5 F° of an adjacent hallway or common room as long as the heat flow rate through the exterior walls and windows is no greater than the heat flow rate through the uninsulated partition walls. Corner bedrooms are more of a challenge than bedrooms near the center of a building, and bedrooms with big windows are more of a challenge than bedrooms with reasonably sized windows.

During the winter, large windows lose a lot of heat at night and on cloudy days. During the summer, large windows can cause heat-gain problems on sunny days, especially if the windows face east or west. A bonus room — for example, a bedroom over a garage — cannot be heated and cooled by a ductless minisplit head located outside of the room. Bonus rooms usually have 5 out of 6 surfaces facing outdoor temperatures, so this type of room needs its own thermostat. Bonus rooms violate a basic tenet of good building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials. design: namely, to create a compact shape. If you want your building to be energy-efficient — and if you expect to heat and cool the building with just one or two minisplits — you need a compact design with as few bump-outs and ells as possible.

All reports are consistent on this point: cold-weather ductless minisplits from Mitsubishi and Fujitsu are performing well at outdoor temperatures that are lower than the units are rated for. (Mitsubishi provides performance data on some of its ductless minisplit models at outdoor temperatures as low as -13°F; many users report that these units are performing well at -20°F.) Marc Rosenbaum has reported, “In temperatures below design temperatures, the units have enough capacity to heat the houses even though we don’t size them with an intentional safety factor.” According to researchers Kohta Ueno and Honorata Loomis, “The MSHPs [minisplit heat pumps] seldom hit maximum power draw, indicating substantial excess capacity even during worst-case winter conditions (much colder than local design temperatures). These results are consistent with the installed capacity of the equipment: the oversizing (compared to calculated loads) typically ranged from 150% to 200%. Although oversizing cooling equipment is commonly criticized, oversizing of heat pumps (for wintertime loads) can be beneficial.

This is particularly true for MSHPs that modulate their capacity, as their highest efficiency is obtained when the unit is running at the lower end of their capacity range.” Of course, it’s still important to perform a heating and cooling load calculation before specifying a minisplit, and it’s still important to choose equipment designed to perform at typical outdoor temperatures in your climate. The point that I’m trying to emphasize is that occasional comfort complaints arise from heat distribution issues, not appliance capacity problems. This rule of thumb was proposed by Ueno and Loomis. To clarify, and at the risk of repeating myself: this rule of thumb is based on distribution issues and room-to-room temperature differences, not on limitations to the heating or cooling capacity of the equipment. If you want to heat your house with a ductless minisplit located in a living room or hallway, you’ll need to leave your bedroom doors open during the day. When the bedroom doors are closed at night, bedroom temperatures may drop 5 F° between bedtime and morning.

If family members don’t want to abide by this approach, or don’t want to accept occasional low bedroom temperatures during the winter, then supplemental electric resistance heaters should be installed in the bedrooms. Turning your ductless minisplit on and off, or controlling it with a setback timer, will result in higher rather than lower energy bills. These units are designed to modulate, and operate at higher efficiencies when they run continuously than when they are turned off and on. Ueno and Loomis wrote, “One homeowner complained of temperature unevenness; when the data were examined, it was clear that they operated their MSHP [minisplit heat pump] in an ‘on-off’ manner, rather than using a fixed setpoint. This resulted in wide swings in interior temperature (between 60°F and 70°F+). The electricity use showed many hours with the MSHP running at maximum capacity, followed by periods with the unit shut off. When operated in this manner, the MSHP is heating at its least efficient (maximum output) state.