An air-source heat pump can provide efficient heating and cooling for your home. When properly installed, an air-source heat pump can deliver up to three times more heat energy to a home than the electrical energy it consumes. This is possible because a heat pump transfers heat rather than converting it from a fuel like combustion heating systems. Air heat pumps have been used for many years in nearly all parts of the United States, except in areas that experienced extended periods of subfreezing temperatures. However, in recent years, air-source heat pump technology has advanced so that it now offers a legitimate space heating alternative in colder regions. For example, a study by the Northeast Energy Efficiency Partnerships found that when units designed specifically for colder regions were installed in the Northeast and Mid-Atlantic regions, the annual savings are around 3,000 kWh (or $459) when compared to electric resistance heaters, and 6,200 kWh (or $948) when compared to oil sy...

The different types of air source heat pumps are described below. Ductless vs. Ducted vs. Short-Run Ducted Ductless applications require minimal construction as only a three-inch hole through the wall is required to connect the outdoor condenser and the indoor heads. Ductless systems are often installed in additions. Ducted systems simply use ductwork. If your home already has a ventilation system or the home will be a new construction, you might consider this system. Short-run ducted is traditional large ductwork that only runs through a small section of the house.  Short-run ducted is often complemented by other ductless units for the remainder of the house. Split vs. Packaged Most heat pumps are split-systems—that is, they have one coil inside and one outside. Supply and return ducts connect to the indoor central fan. Packaged systems usually have both coils and the fan outdoors. Heated or cooled air is delivered to the interior from ductwork that passes through a wall or...

A heat pump's refrigeration system consists of a compressor and two copper or aluminum coils (one indoors and one outside), which have aluminum fins to aid heat transfer. In heating mode, liquid refrigerant in the outside coil removes heat from the air and evaporates into a gas. The indoor coil releases heat from the refrigerant as it condenses back into a liquid. A reversing valve, near the compressor, can change the direction of the refrigerant flow for cooling mode as well as for defrosting the outdoor coil in winter. The efficiency and performance of today's air-source heat pumps is a result of technical advances such as the following: Thermostatic expansion valves for more precise control of the refrigerant flow to the indoor coil Variable speed blowers, which are more efficient and can compensate for some of the adverse effects of restricted ducts, dirty filters, and dirty coils Improved coil design Improved electric motor and two-speed compressor designs Copper tubing, groo...

Every residential heat pump sold in this country has an EnergyGuide label, which displays the heat pump's heating and cooling efficiency performance rating, comparing it to other available makes and models. Heating efficiency for air-source electric heat pumps is indicated by the heating season performance factor (HSPF), which is a measure over an average heating season of the total heat provided to the conditioned space, expressed in Btu, divided by the total electrical energy consumed by the heat pump system, expressed in watt-hours. Cooling efficiency is indicated by the seasonal energy efficiency ratio (SEER), which is a measure over an average cooling season of the total heat removed from the conditioned space, expressed in Btu, divided by the total electrical energy consumed by the heat pump, expressed in watt-hours. In general, the higher the HSPF and SEER, the higher the cost of the unit. However, the energy savings can return the higher initial investment several times during ...

Heat pumps can have problems with low airflow, leaky ducts, and incorrect refrigerant charge. There should be about 400 to 500 cubic feet per minute (cfm) airflow for each ton of the heat pump's air-conditioning capacity. Efficiency and performance deteriorate if airflow is much less than 350 cfm per ton. Technicians can increase the airflow by cleaning the evaporator coil or increasing the fan speed, but often some modification of the ductwork is needed. See minimizing energy losses in ducts and insulating ducts. Refrigeration systems should be leak-checked at installation and during each service call. Packaged heat pumps are charged with refrigerant at the factory, and are seldom incorrectly charged. Split-system heat pumps, on the other hand, are charged in the field, which can sometimes result in either too much or too little refrigerant. Split-system heat pumps that have the correct refrigerant charge and airflow usually perform very close to manufacturer's listed SEER and HSPF. T...

Geothermal heat pumps (GHPs), sometimes referred to as GeoExchange, earth-coupled, ground-source, or water-source heat pumps, have been in use since the late 1940s. They use the relatively constant temperature of the earth as the exchange medium instead of the outside air temperature.  Although many parts of the country experience seasonal temperature extremes -- from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth's surface the ground remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The GHP takes advantage of these more favorable temperatures to become high efficient by exchanging heat with the earth through a ground heat exchanger. As with any heat pump, geothermal and water-source heat pumps are able to heat, cool, an...

The following work aims at demonstrating how a smart thermostatic (radiator) valve network can be used to reduce heating costs by controlling the heat generator (heat-pump, gas boiler, ...) in a more efficient way. Currently, a large proportion of heat generators is controlled by the means of a heating curve, or a similar rule-based logic that mostly rely on outdoor temperature or single point indoor temperature measurements. These simple control laws are in general commissioned to minimize the number of complaints of “cold users”. This results in high forward temperatures, that are energetically non-optimal as they create increased losses in the piping network and also have a negative impact on the heat generator efficiency.  In the proposed data driven approach, a controller was developed to ensure that the radiators receive fluid with the lowest temperature possible, while satisfying the heating needs. To achieve this goal, smart thermostatic valves are used to moni...

Z-Wave radiator thermostats allow you to wirelessly control individual radiators. Each radiator can have it's temperature set and changed throughout the day - manually via a smartphone or based on timed schedules. The Z-Wave radiator valves allow you to have different parts of the house at different temperatures through the day, as you need it. You no longer need to heat empty rooms.   The Z-Wave radiator thermostats are fitted within minutes, they simply replace the existing TRV, no need to drain the system. Once installed they operate just like other Z-Wave devices, such as Z-Wave thermostats, as part of your Z-Wave smart home automation system allowing you to control them wirelessly from wherever you are. Or, you can use other features of the Z-Wave system to control them automatically based on time of day, or from other devices such as Z-Wave Sensors. This enables you bring smart central heating control to your home using your Z-Wave system.   If you've got questions abou...

Thermostatic radiator valve A thermostatic radiator valve (TRV) is a self-regulating valve fitted to hot water heating system radiator, to control the temperature of a room by changing the flow of hot water to the radiator.   Conventional wax motor TRVa The classic thermostatic radiator valve contains a plug, typically made of wax (forming a wax motor), which expands or contracts with the surrounding temperature. This plug is connected to a pin which in turn is connected to a valve. The valve gradually closes as the temperature of the surrounding area increases, limiting the amount of hot water entering the radiator. This allows a maximum temperature to be set for each room.   As the valve works by sensing the temperature of the air surrounding it, it is important to ensure that it is not covered by material (such as curtains). If the controller is removed from the valve, the valve turns on and the radiator will always be hot.   Interaction with room thermostats Thermost...

To control your heating from your phone on a room-by-room basis, you'll need a smart radiator valve (thermostatic radiator valve or TRV). Here are our recommendations.   There’s a reason smart heating is growing in popularity. Not only will it give you more control over the temperature in your home – so it’s always warm when you want it to be – but you can easily monitor your heat and potentially make savings on your energy bills. Still, we’d advise that you take manufacturers’ money-saving claims with a pinch of salt.   If you’re buying an entire smart heating system, it’ll take some time to recoup the cost of the tech but a smart radiator valve is a much smaller investment. Each one will allow you to control a single room, which means you can schedule heating so that it’s warm when it needs to be and no heat is wasted the rest of the time.   Being able to see the temperature clearly on your phone screen or on the de...

Smart thermostats are cool. They save energy, lower bills, and they make your house look like the futuristic residence of a Star Trek character. The problem is, I live in an apartment in New York City that only has a radiator, so I can’t really get in on the connected home action.   Fortunately for me, ecobay, a company that specializes in modern, minimalist smart home tech, just announced at IFA its new Smart Radiator Valves, which adds smartphone control to individual radiators. The Smart Radiator Valve can control valves to start and stop heating the room as desired, allowing for room-by-room temperature control and scheduling. The Smart Radiator Valves look great too, with a translucent plexiglass Philippe Starck design and an e-paper screen for displaying the current temperature.   However, there’s a couple catches to my smart radiator valve dream. First off, while the Smart Radiator Valve lets you control temperature through ecobay’s app (or Apple Home...

The Thermostatic radiator valve is an essential piece of radiator technology. It is one of the many heating controls for controlling air temperature across rooms, and due to its great value and straight forward function it is one of the most popular choices.   A TRV is fitted on the side of your radiator and correctly set up enables you to maximise a single boiler and enjoy different temperatures across different rooms.   The TRV automatically regulates and as a result adjusts the flow of water into your radiator depending on the chosen setting. As the room temperature changes the valve head of the TRV expands, adjusting a pin in the valve so that it either opens or closes. Expansion happens as the room heats and blocks the valve body to receive less hot water into he radiator. Contraction happens as the room cools and as a result opens the valve body allows more hot water to enter the radiator.   What-Are-Thermostatic-Radiator-Valves The key benefit of thermostatic radi...