Location: Bethlehem Pa 18015 Heat Calculations: Proposals received from two different contractors called for 16, 17, and 20 tons. 20 tons includes heating garage and sun room, where 16, and 17 did not. Heat Pumps: System has 4 Water Furnace Envision™ Series NSW NSW060s for about 20 tons of capacity. All supply hot/cold water to a storage tank that is used to circulate water to air handlers and radiant heat. Floors are oak with the coils installed under the sub floor. 15 thermostats control 9 air-only zones and 4 air & radiant zones and 2 radiant-only zones. We have 4 air handlers, one that is used only for the garage. In addition, the three air handlers for the house have steam humidifiers. Each of the 4 HPs has a desuperheater that heats water in a storage tank. Loops: 4 ground loops. One (#1) is vertical (4 bores) and the other three (2-4) are horizontal. Vertical was a difficult to drill, so they switched to horiz. All use Twister pipe. Each HP has its own geo loop. Electric: Electricity is costing us $0.127 per kWh (total $ on bill / total kWh used) For the period 12/15/14 through 01/15/15, use was 12,395 kWh ($1,576.41). We did just switch to a new energy supplier that should lower the generation charge significantly. Air: N/A HP -- EWT / LWT 1 -- 48 / 45.5 2 -- 52 / 49 3 -- 47 / 41.5 4 -- 49 / 45.5 Geo load: 100%. There is no backup except for resistance heat in 3 air handlers (not in garage) Installers: They don't understand why it's so costly to run Costs: We don't have much in the way of previous or expected. We did major renovations to home (added area) and previous owners didn't use the house much. The system is using a Tekmar 406 control. This control is capable of controlling only two HPs or one 2-stage heat pump. The other two heat pumps kick on using delay timers & relays. With the 406 choosing when to turn on the 2nd HP and the 10-minute delays, the secondary HPs were barely running. After changing the delay to approximately 2 or 3 minutes, the secondary HPs are in use more. (See attached images) I have a data acquisition system that measures Amperage draw of each of the HPs and temperatures (RTDs on exterior of pipes at the Flow Center). Note that the values of Amperage are off by a factor of about 145x. The contractor who sold and installed this system led me to believe that the electricity consumption would be equivalent to that of several 100 W light blubs, so I was very shocked to see a $1500 electric bill. Are all of these frequent startup / shutdowns across 4 HPs significant? Is it possible to use a Multi-Staging control like the Tekmar 284 (http://tekmarcontrols.com/products/multi-staging/284.html) to control the HPs better? What is a good duty cycle for these HPs? Is it okay to send 110 to 120F water under my wood floor (it’s installed under the ¾” sub-floor) Is there any sort of bench marking method for how much electricity I can expect to use?