Overload!

 

Your heat pump has its limitations, and unfortunately it can't just pick up more of the weight when you ask it to do more than it was designed to do. Most HVAC contractors will moderately oversize the heat pump units they install rather than expect the equipment to work at its maximum level all the time.

 

What this doesn't do is allow for the remodeler to add a couple of bedrooms to a house and use the same equipment to condition the extra space. There are two things that will definitely happen if this is attempted.

 

First the unit won't be able to sufficiently condition the space. Some people think that if it is too hot in a house, lowering the thermostat will make things better. Of course, this doesn't work because a unit that can't pull the temperature down to 72 degrees is not going to be able to work better if the temperature is set at 68 because it is already doing all it can.

 

Additionally, the unit that runs continuously will wear out sooner, resulting in another large expenditure.

 

 

Attempting to compensate for a unit that is too small by adding more insulation doesn't help the matter, either. Sometimes it is better to have more than one system when a house is very large.

 

For instance, with one portion of a house on a separate system, it may be possible to leave one of the units turned off except when guests are staying or there is some social event.

 

However a house is heated and cooled, the system must be sized correctly for the space for the best cost savings, energy performance, and life of the equipment.