Natural ventilation is the ventilation of a building with outside air without using fans or other mechanical systems. It can be via operable windows, louvers, or trickle vents when spaces are small and the architecture permits. In more complex schemes, warm air is allowed to rise and flow out high building openings to the outside (stack effect), causing cool outside air to be drawn into low building openings. Natural ventilation schemes can use very little energy, but care must be taken to ensure comfort. In warm or humid climates, maintaining thermal comfort solely via natural ventilation might not be possible. Air conditioning systems are used, either as backups or supplements. Air-side economizers also use outside air to condition spaces, but do so using fans, ducts, dampers, and control systems to introduce and distribute cool outdoor air when appropriate.
When central air conditioning service fails during a heat spell, you may have to wait days for an HVAC repair technician or an ac contractor to show up, and you'll probably pay at least several hundred for the repair. But if you're comfortable working around electricity and are willing to spend about $50 on parts, you can probably repair your air conditioning service yourself in about two hours and save about $225 on parts markup and labor.
So, naturally I respond with, “you don’t tell your doctor which medication to prescribe you, do you?” The point is, on the residential level, who you get to install your HVAC unit is far more important than which unit you choose. Keep your options open and let your HVAC contractor make a few recommendations – that’s why you spent time finding a reputable contractor!
An air conditioning system's SEER is especially important if you live in a climate that changes temperature dramatically. The SEER is determined by the cooling output during the winter divided by its electric input during the winter. The higher the rating, the more efficient it will be. In January of 2006, the U.S. put standards in place for cooling units which are still in effect today. They must have a minimum SEER of 13. So, if you live in a home with a system installed before the new standards went into effect, consider having it replaced. SEER 13 units increase home efficiency by 30 percent.
Lennox, on the other hand, is probably the most expensive unit out there and I can’t stand them. In our (humble?) experience, they have a horrible logistics chain, making repair parts difficult to come by (sometimes taking weeks), poor customer service, and the parts cost three times as much. That’s not what this article is about, so read more in: Carrier vs. Lennox Furnace Review.
Central home air conditioner service systems consist of two major components: a condensing unit that sits outside your house, and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the AC contactor, the start/run capacitor(s) and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.
AC units and thermostats have built-in delay features when they're shut down and then repowered. The delay can be as long as 10 minutes. And, if you've subscribed to an energy-saving device from your local power utility, the unit can take even longer to reset. If you've installed the parts shown and reinstalled the disconnect block, repowered the circuit breaker, turned on the switch at the furnace, moved the thermostat to AC mode and lowered the temperature below the indoor temperature, and the unit doesn't fire up after 30 minutes, it's time to call a pro.
HRV/ERV Ventilators: These whole-house ventilators exchange air. They are ideal for homes with what is called a “tight envelope,” homes where house wrap has been applied and airgaps in the attic, around windows, doors and outlets have been sealed. Air in these homes becomes stale and polluted, so exchanging the air is important to IAQ. Heat recovery ventilators (HRV) are designed for cold climates. Energy recovery ventilators (ERV) are best for warm climates. Your cost for an installed HRV or ERV will range from about $2,000 to more than $5,000 based on its capacity and features.
Two weeks go by and no phone call from HVAC Service regarding install date, or any update at all. I call them to check in to see if they have put me on the schedule and when I can expect to have the AC installed. You can tell by the discussion I had with the lady on the phone that they completely forgot about me and have not scheduled anything. She says she needs to get in contact with the owner because she has no idea on the availability of the crane. I was told that she would call me back by the end of the day with an update. Surprise, surprise, no phone call.
Stick with a maximum of 16 SEER units in most cases. Like I said above, contractors push higher SEER units because they make more money, but these units can be expensive at this stage of development, and can drive up your HVAC installation cost. 21 SEER units run about twice the price of a 14 SEER unit, so unless you live in a desert and plan on being there for 30 more years... Likewise, a 16 SEER unit typically costs only about $600-$1,000 more than a 14 SEER, and will usually pay for itself over the lifetime of the unit.
7 To test it, turn the thermostat to OFF, reset the power at the disconnect next to the compressor and the main panel. Set the thermostat to a temperature below the room temperature, and then switch it ON. To avoid straining an air conditioner’s compressor, wait at least five minutes between turning it off at the thermostat and turning it back on. You should hear the outdoor compressor run and see the fan turning inside the top. If the fan isn’t turning, look for an overload button or switch to reset (not all types have this).