There are many terms that we tend to use on the assumption that you know them as well. So this page is here to help you with some of the HVAC speak.
What is a Heat Pump?
A heat pump is an outdoor section of a unit that has a 3 way valve installed so that refrigerant flow can be reversed thereby switching where heat is absorbed and released. Ie when running one way it cools the indoor space and running the other it heats the indoor space.
What is SEER rating?
SEER is an efficiency rating, think about it like the mpg of your system. It has nothing to do with how big or small of an area a system will cool. That is the capacity of the system which is generally expressed in tons. SEER is the ratio of the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses in Watt-Hours. A SEER ratio is calculated over an entire cooling season using a constant indoor temperature and a variety of outdoor temperatures ranging from 60 degrees to 100 plus.
The higher the SEER, the less electricity is required for a central A/C unit to do its job. Keep in mind that SEER ratio is a maximum efficiency rating, like the miles per gallon for your car. Say your car gets 28 miles per gallon on the highway. But if you’re stuck in city traffic it’s a lot less efficient. The same goes for your air conditioner. If your SEER ratio is 21, that’s the maximum efficiency and it could be lower depending on conditions.
You may begin to see advertisement for SEER2 equipment, essentially SEER2 is an updated testing condition for efficiency but works the same way as SEER.
What is a defrost cycle on my heat pump?
When heat pumps run in heat the outdoor section of the unit is in low pressure and the coil is cooling while the inside is in high pressure and releasing the heat absorbed from outside. To achieve this the coil will be operating below freezing and frost over.
Your defrost control board shut put the unit into defrost and keep your outdoor unit from becoming a block of ice. If your unit looks like an igloo it probably has a defrost issue. If your fan outside periodically shuts down and a cloud of water vapor rises out of the unit it is likely operating correctly.
Why not just put as large a unit as possible on every house?
If your ac is oversized it will cause many issues. The first is short cycling. Essentially this means that the unit turns on lowers the temperature of the air quickly and shuts back off. Due to the air not moving enough to balance or condition the unit will turn back on in a short time period. The on/off of this operation is hard on the compressor and other components as they come on/off much more than designed. The other downside to the short cycle is that the system will not have time to removed humidity from the air and leave your home feeling stale and uncomfortable.