4 ms·

This is cool tech but I wonder about the efficiency claims. Depending upon how the HVAC system is designed, where vents are located and where return air is loc

This is cool tech but I wonder about the efficiency claims. Depending upon how the HVAC system is designed, where vents are located and where return air is located, you could cause the HVAC system to run less efficiently if you alter the air flow through the home.

Frozenlock 12y ago
This. HVAC controls most work as a team, otherwise they end up fighting each other. As a simple example, picture an office building in which each room has a temperature sensor and air supply. If a room says "Oh, it's hot here!" The system will try to send cooler air. Now, imagine that in one of those rooms, there's a little lady who's a little cold. The system however, is in cooling mode, because the room is slightly warmer than the temperature setpoint. The lady won't have it a decides to bring an electric heater. Now she is heating her room and feels more comfortable. From the point of view of the system, her room is much warmer than it should be. As a consequence, the system sends even more cooler air to her room. The lady now has to crank up her electric heater to counteract this increase in cooler air...
- dmritard96 12y ago
  There are quite a bit of assumptions to counter here but the first most basic one is that this is intended for office buildings. It is intended primarily at residential after market energy efficiency and comfort retrofits. I Relating your heater example. This applies to current systems even. You plug in an electric heater under your thermostat and its working to cool while you are heating...you simply wouldnt do that.
dmritard96 12y ago
100% agreed on mileage varying. We are building it to treat the on-time of the system as our cost function with requirements around satisfying temperature (and humidity) levels. We know that in some homes the return location, duct leakage and numerous other scenarios can cause efficiency gain impedements. But as long as we are tracking how much time the system is on for, respecting the blower motor (pressure sensors) and satisfying the user requirements for occupied (and unoccupied) rooms, we can at least gaurentee an improvement of 0 or greater %. In most cases, the gains are very substantive as the returns generally tend to be in larger open rooms or hallways. Tracking is a key component to our system.

Frozenlock 12y ago

This. HVAC controls most work as a team, otherwise they end up fighting each other. As a simple example, picture an office building in which each room has a temperature sensor and air supply. If a room says "Oh, it's hot here!" The system will try to send cooler air. Now, imagine that in one of those rooms, there's a little lady who's a little cold. The system however, is in cooling mode, because the room is slightly warmer than the temperature setpoint. The lady won't have it a decides to bring an electric heater. Now she is heating her room and feels more comfortable. From the point of view of the system, her room is much warmer than it should be. As a consequence, the system sends even more cooler air to her room. The lady now has to crank up her electric heater to counteract this increase in cooler air...

dmritard96 12y ago
There are quite a bit of assumptions to counter here but the first most basic one is that this is intended for office buildings. It is intended primarily at residential after market energy efficiency and comfort retrofits. I Relating your heater example. This applies to current systems even. You plug in an electric heater under your thermostat and its working to cool while you are heating...you simply wouldnt do that.

dmritard96 12y ago

100% agreed on mileage varying. We are building it to treat the on-time of the system as our cost function with requirements around satisfying temperature (and humidity) levels. We know that in some homes the return location, duct leakage and numerous other scenarios can cause efficiency gain impedements. But as long as we are tracking how much time the system is on for, respecting the blower motor (pressure sensors) and satisfying the user requirements for occupied (and unoccupied) rooms, we can at least gaurentee an improvement of 0 or greater %. In most cases, the gains are very substantive as the returns generally tend to be in larger open rooms or hallways. Tracking is a key component to our system.