For a residential apartment, a roof-mounted air-conditioning system is the optimal choice. Unlike central air-conditioners that need to be paired with a forced-air furnace, a rooftop unit has only one major component that can be fixed on the roof. This is routed to the duct work that runs through the building, distributing cold air throughout.
Before you install a rooftop air-conditioning system, keep the following 4 things in mind.
- 1. Costs
Because of their ability to cool large spaces effectively, rooftop air-conditioning units are wellsuited for apartments. However, they are more expensive, in terms of both purchase and installation, than their central counterparts. They can cost around$1000 more to buy and almost double to install. This is because rooftop units need to be towed up the building by properly trained technicians. Hauling them up more than two or three stories entails greater safety and property risk, and so contractors will charge more for installation.
The flip side to this is that a rooftop unit uses less energy to run. With central air-conditioners, both the unit and the forced-air boiler, require energy to run. Comparatively, rooftop units do less work and so utilize less energy. This means low utility bills for you.
2. Weight and dimensions
A rooftop air-conditioner has a second heat exchanger and fan that adds to its weight. Therefore, it is important that you consider how much weight your roof will be able to support. Flat roofs offer more support; if you have a sharply peaked roof, you should take extra care during installation. The best thing to do is consult an air-conditioning expert.
If you don’t know how much cooling your home requires, you’ll buy the wrong rooftop air-conditioning unit. It is possible that two rooms with the same square footage will call for different amounts of cooling, because of disparity in insulation. Rooms with double pane windows will require less cooling because not a lot of cold air will be lost to the outside.
Improperly sized systems lead to high utility bills, shorter equipment life and poor air quality. You need to ensure that the unit is connected to a well-laid duct network.
4. Load calculation
The way to size your rooftop air-conditioning system properly is to calculate the heat gains / losses that will occur when the system is running. There are many methods to do this. The most popular ones are Manual N Load Calculation (USA) and CSA standard F280 (Canada). Ensure that your contractor performs the installation in accordance with the Canadian Electrical Code.
Whinstalling a roof-mounted air-conditioning system, ensure that you take all the above things into consideration. It will help you avoid any hiccups and enjoy a smooth HVAC experience.ile