OVER 500 WAYS TO HEAT AND COOL YOUR HOME
In this article, you'll be introduced to a comprehensive range of systems for heating and cooling your home. Your house is probably using 100-year-old technology to heat and - if you're lucky - cool your home whereas new, alternative options could be saving you a ton of money and offering extra benefits. At the end of the article, you will be aware of a range of new options for heating-cooling system types including heat pumps, that provide a more consistent indoor temperature for lower operating costs, and you will be able to identify configurations better suited to your priorities and to your situation than the one your house currently uses. I will also provide a summary table of the systems which lists relative installation and operation costs, life span, and pros & cons of each system.
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Your house is most likely stuck with one of two ways to heat and cool the indoor air, but there are literally several hundred other options available including many based on a heat pump system. A typical heating and cooling is either a furnace or electric baseboards with either portable AC units or a central AC system. There are other options which will save you money, and increasingly varied weather will necessitate sufficient heating and cooling to maintain a comfortable environment.
I’ve spent the past five years focusing on and researching high-performance strategies, systems, and products. Part of my mission is to equip you with knowledge of the diversity of technology available. While I will explain a bit about how a heat pump works, I will also list other systems that are popular outside North America but are gaining popularity and availability locally. Also, passive solar heating and passive cooling are absolutely the least expensive way of moderating indoor temperature, but there will always be situations in which active heating or cooling systems are required. I also include as part of the menu the ways to create hot water since many configurations to heat and cool your house involve domestic hot water.
The most primitive means of heating is basically radiant heat from a fire, and the simplest form is a wood fireplace. This is a good option if you're in a rural area and/or have ready access to plenty of firewood. Most people are familiar with the open masonry fireplace that uses air from the room for combustion and exhaust up through a flue, but these open fireplaces are not suitable for space heating due to their inefficient heat radiation to the room and incomplete combustion that both creates lots of polluting soot and noxious gases - some of which contaminate the air in the room.
However, a wood fireplace insert or complete, closed wood-burning fireplace is a sealed chamber unit with a blower that improves the transmission of exhaust heat into the room and gives an efficiency around 75%. Another blower and/or catalyst improves the combustion to decrease the amount of soot and toxic gases given off and can yield efficiency of 90%.
Where firewood or biomass pellets are not readily available but you have a natural gas service connection, a gas fireplace may be a suitable option. Natural-venting gas fireplaces are open and vent up through a chimney, but these are inefficient at heat transfer. Sealed direct-vent gas fireplaces have a blower that blows air warmed by the firebox and flue. There are freestanding models and insert-type units for both natural-venting and direct-vent gas fireplaces. The lifespan of the shell is about 50 years, but various components of the fireplace need to be replaced after anywhere from 8 years to 25 years.
A woodburning stove consumes wood chips, shavings, or used paper. A biomass pellet stove is fueled by pellets comprised of wood or other organic matter. Both stove types are is very efficient (roughly 65%-80%). An internal blower improves the efficiency of the burn, decreases the pollution exhausted up the chimney, and allows near-horizontal exhaust. Design life is 10 years yet may last as long as 20, but some components need replacement after 5 years.
A tall fireplace built of masonry or concrete which contains the sealed firebox and a convoluted portion of flue burns wood and radiates heat from the entire body of the fireplace.
The other type of direct heat device is a propane or natural gas-fired space heater and is efficient. Gas-fired space heaters are also direct heat devices, create heat quickly and are available as freestanding, portable models or as wall-mounted units. However, this type of heater is a fire hazard and creates a risk of carbon monoxide poisoning.
Gas-fired space heaters and natural gas fireplaces both burn fossil fuels. All fireplaces, heating stoves, and gas fireplaces and space heaters fail to distribute heat to other rooms in a house and to provide water heating; you'll need a water heater that is electric, gas-fired, or combined with a separate or integrated heat pump. All direct heat devices also lack the ability to provide any cooling, so you'll need window-mounted or portable AC units, a separate central AC system, or mini-split systems.
FORCED HOT AIR
An evolution of using heat directly from a fire is a gas-fired furnace. An internal blower pushes indoor air over the hot exhaust tubing to be warmed up and distributed through the house by supply ducting. A furnace may alternately be electric-powered. Hot water is not generated and requires a separate hot water heater. Cooling is also not provided and requires need AC units, a AC system, or mini splits.
HEAT RECOVERY VENTILATOR
A heat recovery ventilator (HRV) or energy recovery ventilator (ERV) is a new kind of forced-air device that combines a heat exchanger with a blower fan. In my article, "HEALTHY HOMES: Breathing Better and Saving Money With A Heat Recovery Ventilator (HRV)", I explain the need for a HRV, its role, and basically how it works. A HRV may have an electric heater or heat pump coil attached, but the HRV/ERV itself will be electrically powered.
HOT WATER (HYDRONIC) HEATING
Instead of hot air, a boiler generates very hot water for heating. A boiler may be electric or gas-fired, but the hot water is distributed throughout the house and radiates the heat away.
The hot water can be distributed through in-floor tubes, hydronic baseboards, or discrete hydronic cabinets. This system can also be tapped into as a means of generating domestic hot water for bathing and washing.
If not burning fossil fuels is important to you, or you don't have room to install ducting, electric resistance heating is a simple solution. Electrical resistance of a heating element generates heat and similar to a hydronic system can distribute heat through different forms. Electric resistance heating does not provide hot water or air cooling; a separate water heater and air cooling system or units must be used.
Electric baseboard heating is reliable and inexpensive to install. It's relatively efficient at generating heat, but the heat is localized to the baseboard units. Furniture placed in front of the baseboards can reduce the flow of cool air from below or the convection of heated air above and into the room.
Additionally, the high temperature of the enclosure can damage anything that comes in contact with it and poses a safety hazard for young children or possibly pets.
ELECTRIC HEATING CABINETS
When you're renovating a heritage house that had steam or hot water radiator cabinets, modern, individual radiator cabinets are a simple replacement, are very efficient, and take little floor space.
ELECTRIC RADIANT MATS
Do you hate the feeling of walking around on cold floors? Electric radiant floor mats are installed in the floor assembly but are most suitable for hardwood, laminate wood, or tile floors. Underfloor electric heating is available for carpeting or rugs, but the carpet and rug acts as an insulator - reducing the efficiency of the heating mat.
HOW DOES A HEAT PUMP WORK?
Instead of burning fuel or putting current through wires to create heat in varying efficiencies ranging from 95% to 100%, equipment that makes use of heat energy ALREADY IN THE AIR to redistribute heat at efficiencies ranging from 150% to 700%. This type of equipment is called a heat pump. Heat pumps can be part of many different system configurations; they greatly expand number of heating/cooling options available.
Consider pumping up a bicycle tire if you have in the past. After you pump up the tire, the pump and tire valve are both much warmer. If instead you release a bunch of air from a bicycle tire, the tire valve gets cold quickly.
The basic principle of heat pump operation is a closed loop of tubing in which gas is compressed in one location, moved to a second location, allowed to expand with the tubing, and pushed forward to the starting point to repeat the cycle. When the gas - which we refer to as the refrigerant - is compressed at the first location, it heats up; the heat is released to the environment by radiation. When the gas expands at the second location, it cools; heat is absorbed from the surrounding environment by radiation. Any air that is above "Absolute Zero" (-273°C / 0°K) has SOME heat energy, so heat may be pulled INTO the home in winter to provide heating or be pulled OUT of the home in summer to "provide cooling".
The input energy required from us is only what's needed to operate the pump that moves the refrigerant and the compressor which compresses the refrigerant. This is a TINY amount compared to the heat energy gained and released by compressing and expanding the refrigerant, and that's enough to warm up or cool down the house. We move several times as much HEAT ENERGY as the amount of ELECTRIC ENERGY that we use to pump and compress the refrigerant.
In summary: a heat pump has a portion which is hot (compressor + evaporator) and a portion which is cold (expansion tank and condenser). One portion of the system will often be a separate unit sitting outside your house; an automatic valve that controls the refrigerant flow will determine if the indoor unit is giving off heat or sending heat to the outdoor unit.
HEAT PUMP SOURCES
A heat pump may be installed as an "air source" heat pump system, or a "ground source" heat pump system. The condenser of an air source heat pump is a unit that sits outside the exterior wall either mounted on the wall or sitting on the ground. A ground source heat pump system includes a heat exchanger coil buried in the ground or submerged in a pond or well.
AIR SOURCE HEAT PUMP
GROUND SOURCE HEAT PUMP
You can read additional details on Natural Resources Canada's heat pump article HERE.
HEAT PUMP DISTRIBUTION
Heat pumps are not really a means of distributing heat to the spaces in your home, but they can transfer heat to a variety of equipment
A heat pump can be connected to ventilation ductwork and is therefore suitable for retrofits or for Passive House homes that use a heat recovery ventilator and ventilation ducts.
DUCTED HEAT PUMPS
If you want to rely solely on the heat pump for heating and cooling OR are using a heating-only system that doesn't use ducts, you can add ducts to a heat pump system sized adequately for the entire home. This is not a common configuration except where a high-performance home reduces the heating and cooling needs. If your house is not located in a region with a very mild climate, you will likely need some supplemental heat on very cold days.
A heat pump may be connected to a variety of hydronic systems.
If your house has a hot water heating system and is well-insulated, you could ..
WATER SOURCE HEAT PUMP
A water source heat pump is system that distributes heat from a ground-source heat pump system throughout the building using hydronic distribution -
NEW TECHNOLOGY HEAT PUMPS
New technology has yielded high-performance heat pumps and heat-pump-based products and systems. The result is far lower energy costs and applicability to a wider range of temperatures.
COLD CLIMATE HEAT PUMPS
Some heat pumps are designed to perform well even in Canada’s colder regions. The Canadian government has a good explanatory article HERE. In the northern interior of British Columbia, a cold-climate rated heat pump will be sufficient to heat a house. Read more on a BC interior case study demonstrating that HERE.
HYBRID HEAT PUMP SYSTEMS
FURNACES AND BOILERS
Let's revisit the older systems - the furnace and the boiler. Each type can be paired with a heat pump; products are available which include the part f the heat pump within the appliance's enclosure and put the other part in a separate, outdoor unit. The reason for combining either a furnace or a boiler with a heat pump is that an average heat pump works less efficiently at very low temperatures. The boiler or furnace will provide ample, supplemental heat.
Consider a really simple, hypothetical scenario to demonstrate. Let's say that:
in hot, summer weather, you need 100 units of cooling - i.e. you need to remove 100 units of heat energy,
in cool, autumn or spring weather, you need only 30 units of heat energy, and
in winter, you need 100 units of heat energy.
How does a typical heat pump that is not rated for cold climates perform?
In the summer, the heat pump operates efficiently, removing 100units of heat energy from the house (providing cooling) while using only 20 units of electrical energy to do it (500% efficiency).
In autumn, the heat pump operates efficiently, providing 30 units of heat energy to the house (providing heating) while using only 6 units of electrical energy to do it (again 500% efficiency).
In winter, the heat pump operates less efficiently, providing 30 units of heat energy while using 20 units of electrical energy to do it. While still "150% efficient", it's not enough heat. A furnace or boiler can easily provide the additional 70 units of heat energy while using 80 units (88% efficiency) of electrical energy or of energy from burning gas or oil.
During the autumn, spring, and mild weather of winter when we need 30 units of heat energy, the heat pump needs only 6 units of energy whereas a furnace would theoretically need 35 units of energy; this is a drastic reduction. However, nearly every furnace is either on or off; it provides either 70 units of heat energy or nothing. Even if it turns on only briefly every so often, the total amount of energy is uses if far more than the heat pump would consume. Additionally, the indoor temperature would be constantly fluctuating between "way too warm" and "cold". This is annoying and uncomfortable, and it's why we typically leave the furnace off until cold weather sets in firmly.
A mini-split heat pump is a two (or more) component system: a compressor/condenser unit outdoors and one or more indoor evaporator units. The evaporator coil and fan may be mounted high or low on a wall or in the ceiling. It may be surface-mounted, recessed to be flush (usually in a ceiling), or installed within a ceiling with only the supply grille visible. As with any heat pump system, it provides both heating and cooling. A house with a heating-only system requires separate equipment for providing cooling, and a mini-split system does that for a low cost.
A mini-split system - either ducted or ductless - is not intended to provide all the heating and cooling for the entire house. It is a good idea to supplement a heating system with or without ducts or to provide heating and cooling to certain rooms or to additions on a house.
The ductless system is the less expensive type of mini-split and the one which requires the least amount of space. This may be why it's the most common configuration around the world.
The cooled or heated air is blown directly from the indoor evaporator unit. Some new, advanced models have sensors and direct the air to occupants in the room.
A house may have:
multiple 2-piece ductless mini-split systems installed or
a single "multi-zone" ductless mini-split system with one outdoor compressor connected by refrigerant pipes to multiple indoor evaporator units
A ducted system is more expensive to install and requires room for ducts, but if you really don't like either the conspicuous wall-mounted evaporator or even a recessed ceiling-mounted cassette, an evaporator concealed in the ceiling space will connect to ducts that terminate at supply grilles in your ceiling or walls.
A house with a ducted mini-split will typically have:
a single "multi-room" ducted mini-split system comprised of one outdoor compressor connected by pipes to one indoor evaporator unit that supplies air through ducts to one room or multiple rooms.
DESIGN AS A SYSTEM
Heating and cooling must be designed as a system to be most effective and economical. Generating heat or providing cooling is one part of the system and may have multiple components in different locations. Distributing that heat or cooling throughout the house is another part of the system and may involve ducting or tubing that require clearances or protection from damage.
The benefit of a heat pump is that it consolidates and reduces your equipment needs. Regardless of whether or not you use a heat pump, you must consider both your heating needs and cooling needs, the resources and services available, and how each will impact the other.
Improving the insulation and airtightness of your walls and roof will forever reduce the need for and cost of heating and cooling equipment. This concept applies to both sophisticated heat pump-based systems and simple direct-heat systems.
My Tuning Report™ - the third step in my design process - identifies and explores a range of applicable options and recommends a few that best fit your needs and priorities. If you apply this new knowledge to your home or future house, you will enjoy a comfortable indoor temperature while saving money. Depending on your current heating/cooling system, failing to take advantage of the information may leave you feeling uncomfortably cold in extreme winter weather, too hot during heatwaves, and be paying increasing energy costs while burning yet more fossil fuel. To further research this topic, watch my video “500+ Ways to Heat and Cool Your House”. If you're ready to take action now, book a Pre-Design Diagnostic Session™ to discuss a plan of action for deciding on the best heating/cooling system for your new or remodeled house.