Whether you’re choosing an HVAC system for a new build or replacing one in an existing home – there are a few incredibly important aspects to consider when you are shopping for your new unit. So, let’s take a few minutes to talk about what you need to know as you embark on your journey to find the perfect HVAC unit for your home.
You need to know how small (or large) a unit you need – this is what we are referring to when discussed your home’s load. It’s the capacity that your unit must be in order to keep you comfortable in your own home. So, it will depend on the square footage of your home. However, it goes beyond that. It also takes into account how many rooms will need to be covered, your insulations R value, your doors, windows, and how many floors your home has.
You may want to speak to the professionals about this to get the most accurate calculation possible. Mathematical formulas are used to ensure all variables are taken into account, and while they may now be computerized, the professionals know how to determine the load more precisely than just using generalized responses. If your HVAC unit is too large it will lead to higher bills and it will shorten the lifespan of your equipment as well, as the cycles won’t be accurate.
Your contractor should handle these calculations for you and if they claim that it isn’t needed or they don’t seem particularly interested in doing it – you’re using the wrong contractor. You may find that your local utility provider will carry out a load calculation.
Why Size Matters
In addition to increasing your utility bills, there are other issues regarding an HVAC system that is too large.
The cooling load has two components – the air temperature (or sensible load) and the air’s humidity levels (or latent load). While a large HVAC system will quickly cool (or heat) the air, what it won’t do is manage your humidity levels effectively. So, in turn you alter the temperature level in hopes of achieving the perfect balance and all this leads to is excess moisture, mold growth, and damage (to your home and your HVAC unit).
Yet, when you have the right size unit your home will be comfortable and you won’t need to keep the unit running as long because it will deal with the humidity levels. In all, having the right sized HVAC unit will make you more comfortable, your HVAC system will operate more efficiently, and you will be spending less money on your utility bills.
When you are looking at the efficiency ratings of HVAC systems there are a few ratings to keep your eyes peeled for. If its air conditioning a rating of 16+ SEER is ideal, while for the gas furnace 94% or higher is what you need, a heat pump should be over 9.2+ HSPF. In every case, the higher the number the more efficient your unit is as your unit will require less energy. It is far worse that you end up with an HVAC unit that is too large rather than too small, however, provided you have an accurate load calculation you shouldn’t need to worry about going wrong with the size of your unit.
You should also have your contractor check your ductwork to ensure ducts are in good condition.