By Stephen Pate – You can increase your heating and cooling comfort and efficiency by aiming your ductless heat pump output at the largest interior door in the room.
Ductless mini-split heat pumps are the current fad in home heating and air conditioning. They boast 3 times energy efficiency over electric heat and even greater efficiency over oil.
The major disadvantage to mini splits heat pumps is indoor unit heat source is in located in one room. You can install multi-head indoor units. Multi-splits can be more expensive, and most people install a single indoor unit.
Aiming your indoor heat pump unit
Aim the air at the door to the adjacent room that needs heat or cooling.
Air-to-air heat pumps have vanes to control the horizontal and vertical distribution of the air. There are settings on the remote for 4 or 5 different horizontal and vertical swings to the air direction.
Set the fan to high and the heat at 74 F. or whatever temperature you want.
Aiming the air flow is not an exact science but easy to get right. Stand in the doorway of the adjacent room you want to heat or cool. Aim the vertical and horizontal vanes until you feel the greatest heating or cooling air in your face.
If there is a chandelier, fan or light fixture in line of sight between the indoor unit and the doorway, you’ll have to raise or remove the obstacle. Think of the chandelier or fan as a rock in a swift moving river. Once the air hits the obstruction, it will curl and eddy in the wrong direction.
Within 1-2 hours you will have equalized the temperature and comfort in the adjacent rooms.
It helps if there is a ceiling fan in one of the adjacent rooms since the static air pressure from the indoor unit fan drops with distance.
Check you setup
To confirm the system is working properly, put a thermometer in the main room and in the other room that you want to be the most comfortable.
I use the Ambient Weather WS-10 Wireless Thermo-Hygrometer to check the temperature in three rooms plus the main room.
Kevin Coulson, energy auditor at Housemaster, gave me this simple tip when I asked him how I could move the heat in the main area with the heat pump to the rest of the house.
His tip worked. Now 1,100 square feet in my home has the same room-to-room consistent temperature from one indoor unit. Generally, the temperature in the furthest room is within 2-degree F. of the main room with the heat pump unit.
Our comfort has improved. We don’t need winter blankets to watch Netflix. My desk is the furthest from the heat pump and I can work in comfort.
We no longer have supplementary heat in the other rooms; therefore, I’m assuming efficiency has improved as well.
Things to consider
Some people install wall vents to improve air circulation with a single source of heat or cooling. A doorway is a 15 larger than a wall vent and it’s already there.
The heat pump fan is very efficient, much more efficient than wall vents with fans.
The fan will only run at high-speed when the indoor unit is providing heat, which is not all the time. The fans are quiet and efficient.
Our heat pump has 18,000 BTU can handle the 1,100 square feet. If your indoor unit is 6-8,000 BTU, your results may vary. It can’t hurt to try this tip. Let me know in the comments if it worked or not.
A person standing directly in the line of sight from the doorway and indoor unit will be warm.
For the relative efficiency of heat pumps versus other heating systems, see High Efficiency Air to Air Heat Pump.