Fresh air ventilation control system
This disclosure relates to a fresh air ventilation (FAV) controller. The FAV controller may include multiple input devices for setting a target fresh air ventilation flow rate (FAVFR), an operating FAVFR for an air handler, an operating FAVFR of a first ventilation appliance, an operating FAVFR of a second ventilation appliance. The FAV controller further includes electric interfaces adapted to couple to the air handler and a thermostat for controlling the air handler, a sensor for monitoring an operation of the first ventilation appliance, the second ventilation appliance, a thermometer for monitoring temperature of fresh air in a ventilation path to the air handler, and a motorized damper disposed in the fresh air ventilation path. The FAV controller may be configured to monitor operation times of the air handler, the first ventilation appliance, the second ventilation appliance, and the thermometer via the electric interfaces, and to control the air handler and the motorized damper, and/or the second ventilation appliance via the electric interfaces.
1 . A fresh air ventilation control (FAVC) apparatus, comprising:
a first electric interface adapted to couple to a sensor for monitoring an operation of an exhaust appliance;
a second electric interface adapted to couple to an air handler and a thermostat for controlling the air handler;
a third electric interface adapted to couple to a thermometer for monitoring temperature of fresh air in a ventilation path coupled to a return path of the air handler;
a humidity sensor for monitoring relative humidity of a return air of the air handler; and
a system circuitry configured to, based on the temperature of fresh air and the relative humidity of a return air being within threshold ranges, transmit a call to request supplemental fresh air, wherein the system circuitry is configured to, during runtime, reduce a ventilation call runtime to a predetermined percentage that facilitates supply of the supplemental fresh air when the relative humidity is above 50%.
2 . The FAVC apparatus of claim 1 , wherein:
the system circuitry is configured to transmit the call to request supplemental fresh air when the temperature is in a range between a threshold minimum temperature and a threshold maximum temperature.
3 . The FAVC apparatus of claim 2 , wherein the threshold minimum temperature is about 17° F.
4 . The FAVC apparatus of claim 2 , wherein the threshold maximum temperature is about 100° F.
5 . The FAVC apparatus of claim 2 , wherein:
the system circuitry is configured to transmit the call when heating is active and the temperature is above the threshold minimum and below a heating temperature threshold.
6 . The FAVC apparatus of claim 5 , wherein:
based on the heating being active and the temperature being above the threshold minimum and below a low ventilation temperature threshold, the system circuitry is configured to reduce the ventilation call runtime; and
the low ventilation temperature threshold is below the heating temperature threshold.
7 . The FAVC apparatus of claim 5 , wherein the heating temperature threshold is about 40° F.
8 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to restrict ventilation or terminate ventilation when the relative humidity (a) is above 55% and (b) is not dropping or is rising.
9 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to transmit the call to request supplemental fresh air when (a) the temperature is in a range between a heating temperature threshold and a threshold maximum temperature and (b) the relative humidity is below a threshold humidity.
10 . The FAVC apparatus of claim 1 , wherein the ventilation call runtime is reduced to 25% when the relative humidity is above 55%.
11 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to restrict ventilation or terminate ventilation when the relative humidity is above 55% until the relative humidity drops below 50%.
12 . The FAVC apparatus of claim 1 , wherein a dehumidification is not active until the relative humidity rises above 55%.
13 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to permit ventilation when the relative humidity does not exceed 65%.
14 . The FAVC apparatus of claim 1 , wherein compressor activity is required for ventilation when the relative humidity is above 50%.
15 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to progressively restrain ventilation according to the relative humidity.
16 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to not restrict ventilation or to not terminate ventilation when (1) the temperature of fresh air is below 70° F. and above 25° F. and (2) the relative humidity is below 50%.
17 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to not restrict ventilation when (1) the temperature of fresh air is above 70° F. and below 90° F. and (2) the relative humidity is below 50%.
18 . The FAVC apparatus of claim 1 , wherein compressor activity is required for ventilation when the temperature of fresh air is above 85° F.
19 . The FAVC apparatus of claim 1 , wherein the system circuitry is configured to reduce ventilation when the temperature of fresh air is above 90° F.