HEAT PUMP SERVICE & MAINTENANCE

Goals
It’s critical to know what you want from your heat pump from the start. People switch to heat pumps for a variety of reasons, including cost savings, comfort, reduced environmental impact, convenience, and aesthetics. Share your objectives with your installer to ensure proper siting and installation. It’s also a good idea to talk about whether the heat pump will be the only heating system, the primary system, or a supplemental system.

Budget
The number of indoor units installed and the complexity of the installation are the primary drivers of heat pump costs. Costs can be reduced by maximizing the amount of space that each indoor unit heats and cools, as well as by selecting locations that are convenient for installers.

Considerations
Location of the indoor unit
Heat rises — While an indoor unit may provide heat to the floor above, it will not provide heat to the floor below. Similarly, cool air from a first-floor air conditioning unit will not cool floors above it. Heated air is unlikely to flow past an ascending stairwell, and cooled air is unlikely to flow past a descending stairwell.
Consider the flow of air — Air flow is difficult to predict, and each building is unique. In general, open spaces are easier to heat and cool with a single indoor unit, whereas heat can be difficult to transfer through a doorway into other rooms. A heat pump located outside the room will not benefit a room with a typically closed door.
Connections should be simplified — Finding novel ways to simplify installation can save money while also improving aesthetics. Look for ways to locate indoor units so that line sets can be run through closets, basement/attic stairways, attached garages, basements, crawlspaces, attics, and the outside of your home to minimize exposed tubing and wiring (line set) without the cost of patching walls and ceilings. Exposed line sets should be protected with covers and painted to match the walls.
Thermostat coordination — The interaction of existing thermostats can be challenging. If an existing thermostat (say, for a boiler) is in a space heated by a heat pump, the boiler thermostat may never fall below its setpoint and may never request heat. As a result, other zones (for example, bedrooms served by the boiler but not by the heat pump) may become cooler than desired. Consider moving the boiler thermostat to another part of the boiler zone during your heat pump installation if you are not adding multiple heat pumps to cover the entire boiler zone.
Types of indoor units
Here are some things to think about when selecting an indoor unit:

By far the most popular are wall units. They are the most efficient and can heat or cool a large area because they are mounted high on a wall. They are also the most noticeable.
Floor units are attached to the wall by the floor. They are less noticeable, but not as efficient. Because their airflow can be obstructed by furniture, they may not be able to heat and cool as large an area.
Ceiling cassettes are installed above the ceiling and only their vents are visible. They are typically the size of a suspended ceiling tile, and their edges blow air in four directions. They are almost imperceptible, but they are less efficient and may not be able to distribute warm and cool air as far as a wall unit. These are commonly found in attic floors or above suspended ceilings.
“Mini-Ducts” or “Compact Ducts” have an indoor unit above the ceiling or below the floor that is connected to one or more registers via short runs of ductwork. The main advantage is that the indoor unit is hidden and the registers are unobtrusive. Because a single indoor unit can be ducted to multiple registers, they are ideal for heating multiple small rooms such as bathrooms and bedrooms. An indoor unit installed in an insulated attic connected to a grill in a hallway ceiling below is a common configuration. The air from the hallway is returned to the unit, heated or cooled, and then distributed to multiple adjacent rooms via ceiling vents. They can also be installed beneath a floor (typically in the basement ceiling below). Superinsulated homes with low heating demands may be suitable for a small mini-duct indoor unit with ducts running throughout the house.
Ductwork should ideally be designed by a ductwork expert to be as short, fat, straight, insulated, and sealed as possible. The entire system (indoor unit, ducts, and vents) should be contained within the home’s insulation shell. It should be noted that if each room lacks its own “return” and “supply” vents, the distribution of conditioned air can be significantly affected by doors being opened or closed. Consider that all connected spaces will be heated/cooled using a single shared thermostat.

Location of the outdoor unit
Heat pump without ducts Outdoor units can be installed dozens of feet apart from their indoor counterparts, giving you a lot of flexibility in where you put them. Here are some points to consider:

Aesthetics — This is a highly personal but important consideration. It can take some getting used to seeing a heat pump. Your outdoor unit’s visual impact can be reduced with careful planning.
Unobstructed airflow — While it may be tempting to tuck units into tight spaces for aesthetic reasons, keep in mind that they extract heat from the outside air. The more access they have, the better their work will be. Avoid shrubs, locations prone to snow drifts, and structures that could obstruct airflow.
Interference with doors, windows, and walkways — It’s best to avoid installing the outdoor unit where it could interfere with the operation of a door or window. Furthermore, when outdoor units defrost in the winter, they release water, which can cause icy patches. Choose a location where this will not be an issue.
Roof runoff — If the outdoor unit is going to be installed under a roof drip line, make sure it has a rain cap.
When choosing an installation location, consider the ease of service.
Considerations for outdoor units
Mounting — A mounting system’s primary goal is to keep the outdoor unit above the snow.
Foundation brackets are the best at reducing noise and keeping rakes, shovels, and lawn mowers out of the way.
Ground stands reduce noise but are vulnerable to frost heaves if installed with insufficient drainage.
Wall mounts keep units away from rakes, shovels, and mowers, but they can transmit noises into the house. The noise may resemble the hum of a truck idling on the opposite side of the street.
Single-zone vs. multi-zone systems
Advantages of System Type
Disadvantages
Single-zone
Reduced operating expenses
More efficient, particularly at low speeds
improved dehumidification
If one unit fails, the others continue to function.
Each room can be in a different mode at the same time (e.g., AC, dehumidify, fan-only, and heat)

Multi-zone
Reduced maintenance costs
Less outdoor space is needed.
Less obvious
Each indoor unit’s temperature can be controlled independently. However, if only one room’s heat is turned on, a small amount of heat is still delivered to the other rooms, potentially making some rooms uncomfortable.
Dimensions — When it comes to heat pump indoor or outdoor unit sizing, bigger isn’t always better. Smaller units are more efficient and can often provide better air conditioning than larger units.
Other factors to consider
Aside from the outdoor and indoor units, here are some additional factors to consider during installation:

Line sets — Two insulated copper lines and one wire connect indoor and outdoor units. It’s easiest to conceal them in a closet, basement ceiling, attic floor, or on an outside wall, but they can also be concealed within a wall. Matching the color of outdoor line sets to the exterior of a house and making them shorter can help to reduce their visibility. These decisions have an impact on both costs and aesthetics.
Condensate drain line — When indoor units are in air conditioning or dehumidification mode, condensate is produced and transported by a drain line. This water can be discharged into a sump pit, sewer line, garden, or gutter.
Code Prerequisites — To ensure code compliance, as with most residential and commercial equipment installations, consult with your installer. These specifications may have an impact on installation costs.