HVAC Technology
HVAC Technology has come a long way from the clunky old thermostats. Gone are the days when you must get up and change the temperature in your home or business. All this now happens from your very own smart devices!
Inverter-driven compressors
Picture this: Seattle’s warm day in mid-July, and you hear your AC system click on. The system quickly satisfies the temperature change within a degree or two of your setpoint, say, 72 degrees F, and the AC system abruptly shut down. Then about fifteen minutes later, the process is repeated until the evening when the outside temperature drops. This is known as short cycling, and over the long term, it uses more energy than necessary through pressure cycling and transient heat loss and can severely impact the lifespan of your compressor.
Compressor Speed
Most compressors out there are of the fixed-speed type: all or nothing, 0 or 100. This is like having a vehicle that only drives at 70 mph. While it would be great if you lived on a freeway on-ramp, it would not be practical for 90% of your driving scenarios: picking up the kids from school, going on a quick grocery run to PCC, etc. In this analogy, the average cooling or heating demand is an errand within a mile of your home. Instead of repeatedly driving one mile at 70 mph, it would be much more efficient to get there at a reasonable speed and then remain in the vicinity. That is exactly what having an inverter-driven compressor is like.
Efficiency
Recently, in the HVAC industry, inverter-driven compressors have become much more commonplace. These innovative designs initiate at around 15% operating capacity and only go to as high as needed to satisfy the demand for heating or cooling. Then the compressor ramps down to a level where it can maintain the temperature and efficiently hovers. Over an extended period, such as a whole cooling season, the ability of the inverter drive to more efficiently modulate cooling capacity can add up in terms of energy costs saved. It also keeps a more consistent temperature in the space. The following chart compares an inverter-driven compressor with a traditional fixed-speed compressor regarding energy costs saved.
Recently, the options for controlling residential HVAC systems have greatly improved with HVAC Technology. Gone are the days of simple, mechanical thermostats (such as enclosed mercury bulbs or bi-metallic sensors). With recent developments in smart thermostats, a homeowner can now control their HVAC system from their mobile device or tablet anywhere in the world. With these systems, a Wi-Fi-enabled sensor checks humidity and temperature levels at a sensor location inside your home and can even track and report what times of the day, week, or year you used your system most. You can create programs and schedules to more accurately tune your home’s comfort settings.
Forget to turn down the heat when you left for that business trip? Want to make it more comfortable before you arrive home? Now you can adjust the condition of your home’s air while you’re taxiing on the tarmac.
Occupancy and Condensation Sensor Modules
Have you ever turned on the bathroom exhaust fan to clear out the steam from your shower and then left the house only to come home hours later to find it is still running? Oops…we all have! There’s a better way: With Condensation sensors, we can fit up a bathroom exhaust fan to engage when someone is taking a shower or hot bath and shut off once the condensation is removed from the air.
No more misty bathrooms with HVAC Technology. . .
There are similar modules for occupancy; once you and your family are home for the afternoon and moving around, the sensor engages and switches on the fan, changing out stale high-CO-air for fresh air. This can be part of a Whole House Ventilation system or an ERV.
Seasonal Energy Efficiency Ratio or SEER is a measure of the efficiency of an HVAC system. The SEER rating of a unit is the cooling output during a typical cooling season divided by the total electric energy input during the same period. The higher the unit’s SEER rating, the more energy-efficient it is.
A decade-and-a-half ago, when most of the systems in operation were built, SEER ratings were around 9 or 10. If a unit needs HVAC maintenance (has a poor charge, and needs to be cleaned, especially the electrical contacts. Click here to schedule a preventative maintenance visit), the effective SEER rating can be even lower. Now the SEER rating can be anywhere between 14 and 30. If you replace your old system with a higher efficiency unit, you can reduce energy costs.
In an older home or a space with really high ceilings, installing ductwork may be impossible or cost-prohibitive. In some cases, running additional ductwork to tie in with an existing system may be inefficient. The whole system will have to be upgraded to accommodate an addition or a problem area in an existing space. (hot or cold zones) In these scenarios, a ductless mini-split system is a great alternative.
While these HVAC systems have been widely available in Europe, Latin America, and Asia for quite some time, they didn’t appear in the US market until much later. These efficient systems can provide multiple heating or cooling zones, and each zone can be operated and optimized independently to address different needs in an existing space. This technology is continuously being improved- a true innovation!
At the Forefront of HVAC Technology
At Morgan Mechanical, we install a few ductless mini splits and new construction in existing condos and houses. Often they are used to cool a single zone addition or convert a garage or attic into a livable space. With unique ductless technology, such as VRF (variable refrigerant flow) systems, we can create comfort zones that homeowners and their families can control independently. VRF systems can even simultaneously provide AC and heat to various space zones.
Every home is susceptible to indoor air quality issues on occasion. These can exacerbate common respiratory ailments such as asthma and seasonal allergies. I recently read some concerning statistics regarding the quality of the air inside the average home:
- “Americans, on average, spend approximately 90 percent of their time indoors, where the concentrations of some pollutants are often 2 to 5 times higher than typical outdoor concentrations.” and:
- People who are often most susceptible to the adverse effects of pollution (e.g., the very young, older adults, people with the cardiovascular or respiratory disease) tend to spend even more time indoors”(Read more here: https://www.epa.gov/report-environment/indoor-air-quality)
Questions about Air Quality
We get questions about these sorts of things all the time. The bottom line is this: the in-line filtration that exists on most ducted systems, while beneficial, is not enough to address health concerns like airborne bacteria and viruses (Legionnaire’s disease, etc.), allergens, and other respiratory irritants including mold, dust, smoke, radon, and VOCs. The airborne irritants in the average home are too small to be picked up by the filters on the AC system. While these keep dust out of your ducts, we often say these are for your AC system’s health but not your lungs.
Technologies
Choose one of the many air cleaner technologies currently on the market to address the minor particulate irritants that are suspended in your home’s air. Let us guide you through an assessment of your home’s indoor air quality and which features you need, and we can make a plan to install a system that can remove the pollutants in the air. Air cleaner technologies include UV light, ionization, or electrostatic means to clear the air. Each has its advantages and limitations. An assessment of your indoor air quality will guide the discussion as to which type of air cleaner is appropriate for your needs.
ERV System
All homes need adequate ventilation. Does this mean that all houses have it? Not exactly. Based on the occupancy of a space, the idea is to calculate how much humidity will exist in the home and to constantly maintain 30-50% relative humidity and refresh the air inside a space with fresh air from outside. We aim for approximately one air change per hour. This is achieved through whole-house ventilation (also referred to as a whole-house fan).
One such whole-house ventilation system is an ERV or energy-recovery-ventilator. This unit uses a heat exchange device to condition incoming (ventilation) air and serve as means for continuously refreshing the air inside of a space. During the cooling season, the device dehumidifies and removes heat from the outside air as it is brought into the room. During the heating season, the ERV does the opposite: Removing heat and moisture from the exhaust air before blowing it outside and using this to warm and humidify incoming ventilation air.
The average AC unit from just 20 years ago produces 80 or more decibels of sound at the condensing unit (outdoor unit.) Today, that number is down to between 40 and 50 decibels. That’s the equivalent of a polite conversation (think library voice) or a light rain . . .
This is a significant improvement, especially considering that the decibel scale is logarithmic, meaning that 40 is not half as loud as 80 but approximately one-eighth as loud. Eighty decibels are on par with a loud vacuum cleaner or dishwasher disposal. Due to some of the other improvements we’ve mentioned, like inverter-driven compressors and quieter fans, the neighbors don’t have to know when you’re AC-unit has come on!
Whether its a residential or commercial project most newer systems use a computer to control the parameters of the system. This provides distinct advantages when a component of your system is failing. Our repair technicians can connect to the equipment and read diagnostic information. A repair technician can diagnose problems and adjust settings remotely with some system controllers. These tools can help reduce the wait time and cost of a diagnostic visit.
