The Most Common Mistakes with Geothermal Heat Pumps In HVAC
Geo heat pumps, also referred to as ground source heat pumps tend to be one of the most efficient and cost-effective ways to heat and cool a home or a commercial building. However, the installations of these devices occasionally go wrong, usually as the result of inexperienced designers or installers. In this post, we are going to cover the some of the common mistakes and how to avoid them:
This is not only common with geothermal heat pumps, but with more conventional devices such as air conditioners. Most contractors still utilize the rules of thumb for sizing equipment and then adding a huge safety factor to make sure the equipment is large enough for the job.
Oversizing not only forces the pumps to use more energy than needed, but it also causes short-cycling of on and off, which tends to wear the equipment down faster. Also, since oversized equipment has a shorter runtime, you do not get the same amount of air circulation and filtration throughout the house. This can lead to more prominent temperature variations.
Installing the Wrong Pump
The circulator pump is responsible for moving water through the ground and into the heat pump. The circulator pump needs to have enough power to overcome the pressure drop of the primary pump as well as the friction from the piping and fittings. That means if the pipe is too small, there won’t be enough water flow through the heat pump. This will hurt unit efficiency or cause other malfunctions. On oversized circulator pump, on the other hand, will use more electricity than needed. An experienced contractor will choose a pump based on your heat pump and on head loss calculation.
Any number of different experts may be involved, usually depending on the size of the project. Such experts include HVAC contractors, drillers, general contractor, engineers, architects and the owner. The more parties involved, the more important proper communication becomes.
So, for instance, the HVAC contractor needs to be notified of any adjustments that the architect makes in the floor coverings to ensure the radiant floor works properly.
Ideally, one contractor should be responsible for all aspects of the geothermal heat pump including the ducting, trenching and drilling. This way, if anything goes wrong, there is no blaming other parties and the contractor in charge can remedy the issue.