Heating

Radiant Heat

The main house is heated with seven zones of radiant floor heat. Radiant heat:

• Keeps your feet warm
• Provides more uniform room temperature so you are more comfortable
• Uses less energy since most people set the thermostat 6-8 degrees lower
• Eliminates dust and allergens circulation through forced air components

Zones: Dividing the system into many zones with separate programmable thermostats saves energy since each zone is only heated at the times of the day when it is occupied. The zones are:

1. The Main Floor Master Bedroom zone includes the bedroom, closet, and bathroom. The thermostat mounted on the east wall of the bedroom entry is programmed to heat these rooms in the morning and evening. The heat distribution manifold is under the west bathroom sink.
2. The Family Room zone includes the kitchen, informal dining area, powder room, pantry, and family room. The thermostat on the east wall of the family room is set to a fairly even temperature all day. The distribution manifold is also on the east wall.
3. The Living Room zone includes the main entry hall, the dining room, and the living room. The thermostat on the north wall of the dining room heats the room in the morning and evening. The manifold is in the center hall closet.
4. The Upstairs Master Bedroom zone includes the bedroom, dressing room, bathroom, closet, and balcony. The thermostat on the north wall of the dressing area heats these rooms in the morning and in the evening. The manifold is in the west wall of the closet.
5. The Office zone includes the two offices, the laundry, and the office hallway. The thermostat in the hallway outside the laundry heats this area during working hours. The manifold is behind the laundry door.
6. The Upstairs Bedroom zone includes the two bedrooms, two bathrooms, two closets, and the landing. The thermostat in the landing heats these rooms in the morning and in the evening.
7. The Downstairs zone includes all the downstairs rooms except the storage areas and the utility room. These radiant tubes are embedded in the 12" thick concrete foundation slab. The huge thermal mass of the slab makes it impractical to vary the heating regime during the day. It is still nice to do most of the heating during the daytime so the floors feel warmer when you are walking on them. The thermostat is in the play room and the manifold is the northern one (by the door) in the east wall of the wine cellar.

Plumbing: The system layout is a primary-secondary loop similar to Figure 6-6 "Single Boiler Zoned with Valves" on Page 38 of the Lochinvar Knight Installation and Operation Manual. The high efficiency KBN080 boiler provides heat for both the radiant heating system and domestic hot water.

In the boiler loop, the flow goes from the boiler through

• the pressure and temperature relief valve
• a pressure and temperature gauge
• a drain and purge valve
• a Honeywell PV100 SuperVent air separator with TK300-90 expansion tank and FM911 backflow preventer and fill valve
• closely spaced tee
• Grundfos UPS15-58FC circulator with check valve
• a fill and drain valve
• back to the boiler

In the radiant heat system loop, the flow goes from the closely spaced tee through

• system temperature sensor
• Grundfos UPS26-99FC circulator with check valve
• Watts seven branch stainless steel 1" flowmeter manifold with a pressure differential by-pass valve
• 5/8" PEX-Al-PEX distribution piping
• the RHT FN5 zone manifolds
• 1/2" PEX-Al-PEX piping in the floors
• back to the zone control actuator valves on the Watts manifold
• back to the closely-spaced tee

In the domestic hot water loop, the flow goes from the boiler loop supply through

• a Grundfos UPS15-58FC circulator with check valve
• a Honeywell FV180A air vent
• the heat exchanger in the Stiebel Eltron storage tank
• back to the boiler return line

Wiring: The thermostats send requests for heat to the Honeywell R8889A1014 and R8889B1012 control boards. The board opens the appropriate zone valve and then requests heat from the boiler controller. The boiler controller starts the circulators and then fires up the boiler to supply the heat. The boiler controls the three circulators in the system, giving domestic hot water priority over radiant heat. The line voltage wiring is shown in Figure 8-1 "Line Voltage Field Wiring Connections" on Page 46 of the Lochinvar Knight Installation and Operation Manual. The low voltage wiring is shown in Figure 8-3 on Page 49.

Guesthouse

Like the main house, the guesthouse is very highly insulated so the heating requirement is very low (~8.5 KBTU/hr). It is difficult to find a gas heater this small, so three electric heaters were installed. The main room and the bedroom have King Electric Pic-A-Watt in-wall fan heaters with Honeywell LineVoltPRO 8000 Programmable Line Voltage Thermostats. The bathroom has a heater on a switch as part of the ceiling Panasonic fan-light-heater unit.