What’s a BTU and How Many of Them Do I Need to Heat or Cool My Home in Central Maine?

BTU is short for British Thermal Unit. When heating, we are talking about the amount of heat given off from the fuel or energy used by the heat pump. When cooling, we are describing the heat pump’s rated capacity to remove heat from a building or home. Don’t worry, our heat pumps do both and can be changed from heat mode to cool mode with the push of a button.

The best way to discuss your exact BTU requirement is to call Valley Home Services at (207) 945-9008 and schedule a ductless heat pump installation consultation.

BTU calculations for your home depend on a variety of factors.

The two most important variables are square footage and ceiling height. Outside temperature, insulation, and personal preferences will also play a role in your BTU needs. A whole-home heating or cooling system will generally require greater BTU output than a zoned temperature control solution.

You might see several different formulas for calculating BTU needs. You can multiply the cubic feet of space by the number of degrees of change required and then multiply that number by .133 to get the BTUs per hour you’ll need to reach your desired temperature. The convenient thing about this formula is it works for a single room or a whole home.

To get the cubic footage of a space, don’t forget to multiply by the height of the ceiling as well as the length and width of the room. The average bedroom size is roughly 11 feet by 12 feet for a total of 132 square feet. The standard room height is 9 feet, so you multiply 132 by 9 and get 1,188 cubic feet.

For example, if your home is at 60 degrees and you want a zone heat pump to warm your bedroom up to 74 degrees, your heat pump in your bedroom will need to increase the temperature by 14 degrees. The calculation would be 14 degrees of change x 1,188 cubic feet x .133 to get the BTU output you’ll need per hour, which would be 2,212.

The lowest ductless mini-split heat pump that we recommend is a 9,000 BTU heat pump, and based on Efficiency Maine Rebates, we often direct Mainers to 15,000 BTU units as the best size in order to maximize your savings and efficiency. We do install units up to 36,000 BTUs, especially when working in commercial or large spaces. Many of these mini-split heat pump units are designed to act as the sole source of residential heating and cooling for several individually zoned rooms.

For very small rooms, the BTU capacity on even the lower-end ductless heat pumps can exceed the output needed to provide heating or cooling for a single room in your home. Our consultants can discuss options with you on how to heat or cool multiple rooms based on your lifestyle and needs.

We often find that a home does not need a heat pump in every room, and there are a variety of systems that can be zoned in every living area of a home to offer a comprehensive alternative to centralized forced air systems. Of course, having different zones, segmented spaces, or just multiple floors within your home is the main speed bump when calculating BTU needs. If it was an easy calculation, there would be no need for heat pump consultants! Learn about about Short Cycling here, another consideration regarding the placement of your indoor heat pump.

The other thing to keep in mind is the personal preference of residents. One of the zoned heating and cooling benefits that central air systems simply can’t replicate is personalized comfort. Do you have a housemate who likes their room to be cold when they sleep, while you like your room to be a balmy 75 degrees? Different preferences may require a range of different BTU outputs per wall-mounted air handler. In most multi-zoned household situations, there are going to be rooms with different temperature needs at different times depending on if the room is occupied and by whom. BTU needs will vary over the day, night, and seasons.

What’s the Difference Between a BTU and a BTU/hr or BTUH?

BTU/hr., sometimes written as BTUH, refers to the amount of heat the heat pump can remove from the air per hour. You may notice that this notation of “/hr” or the added “H” is often dropped and simplified to just “BTU.” If you’re familiar with or comparing central air conditioning units, then they generally use tonnage as a measurement of cooling power instead of BTU. One air conditioner ton equals 12,000 BTU/hr.

How to Choose the Right Mini-Split Ductless Heat Pump Size

You should consult with an expert in mini-split heat pumps to get a better idea of the heating and cooling output your home will require. In Bangor, Brunswick, and the surrounding areas of Maine, heating and cooling needs can vary dramatically throughout the year. It’s not uncommon to experience muggy days in the high 80s or low 90s in July, or temperatures that dip below zero on especially cold nights in December, January, and February.

Mini-split ductless heat pump systems are an ideal solution for home and business owners who want to minimize their heating and cooling costs by narrowly targeting their BTUs where they’re most needed. Don’t spend hundreds of dollars a month heating or cooling your entire home when it’s just a few rooms that really require precise temperature control.

They’re also the ideal solution for lofts or addons that aren’t connected to central air systems or as an affordable heating or cooling solution for multi-family housing. The use cases for ductless heat pumps are many, and a new system could be the perfect option for your needs.

Call Valley Home Services at (207) 945-9008 to schedule a ductless heat pump installation consultation.