Frequently Asked Questions

An AWHP is a new (to the USA market) type of ultra-high efficiency heat pump that (outdoor unit is a “self-contained “appliance” and keeps all of the refrigerant outdoors) connects to indoor heating, cooling, or hot water loads or equipment via insulated PEX water lines. AWHPs are used with any, all, or a combination of radiant heating, radiant cooling, ductless room fan coil units, duct system air handlers, and hot water heater tanks (indirect type).

The Chiltrix air-to-water heat pump (reverse cycle chiller) does not consume any water and works in all humidity conditions. It uses an ultra-high efficiency DC-Inverter variable speed compressor with a small amount of refrigerant ,self-contained in the outdoor unit. The water or water/glycol fluid is only used in a sealed loop, to transfer heating or cooling between the outdoor unit and the indoor equipment. No water is consumed.

In general, the Chiltrix air-to-water heat pump chiller can support any number of ducted and/or ductless indoor units, that together, do not exceed the BTU capacity of the heat pump(s). It is also normal to specify more indoor unit capacity than the math supports, as long as you realize that the indoor units cannot all run at full speed at the same time and still deliver their full rating.  As long as the outdoor equipment is sized to properly match the total indoor load, it will generally work itself out. You can select any combination from our wide assortment of high-wall “mini-split” type, ceiling cassette type, Euro-style low wall/floor units,  and from our wide range of standard size (or small-size) ducted air handler units. All of these can be mixed/matched/combined as desired.

Chiltrix has multiple available sizes of outdoor units available ranging, from 2 to 5.5 tons each. They are also modular, meaning that multiple units of the same, or different, sizes can be combined in any combination to achieve perfectly sized systems up to 11.5 tons cooling and 16.5 tons heating.

We offer a complete line of hydronic ducted AHU (air handler units) for ducted systems. These connect into a ducted system in the same standard manner as a regular freon-based AHU. You can see more information here. In addition, you can use any standard  hydronic fan coil or ducted air handler from the open market, but if so please contact us to help with sizing as this type of unit sizing  calculation may be non-standard.

1. Same or better cooling performance, better heating performance.
2. Ability to totally integrate variable backup heating, no “heat strips” or portable heaters ever needed.
3. Ability to also perform domestic water heating.
4. Ability to work with radiant heating (and/or radiant cooling in most climates).
5. Can work with any or all of ductless, central duct, mini-duct, radiant, water heating, all in the same application.
6. No refrigerant handling, self-contained outdoor unit is an “appliance”, enables DIY or lower-skill installation.
7. No refrigeration license needed, can be installed by HVAC, plumber, skilled handyman, certain homeowners.
8. No refrigerant is ever inside the building envelope. This is very important as the new refrigerants present new hazards and VRF uses a LOT of refrigerant indoors. VRF is already banned or being restricted in commercial and US Govt. applications, and for good reasons.
9. Indoor-side system, once installed, is future-proof and uses a water or water/glycol mix, it is compatible with future technologies, and next-gen refrigerants that you definitely don’t want indoors. The newer high-efficiency and environmentally friendly refrigerants tend to be highly toxic and/or flammable (refrigerants such as R454B, R32, R290, R717, etc., this is stuff that you don’t want inside the building envelope. See more here.
10. No arbitrary line-set length limits or vertical lift limits.
11. Multiple indoor head units possible – up to 12 or more indoor units per outdoor unit, according to the loads and design.
12. Leaks – in a multi-head (or VRF) mini-split system, if there is ever a leak, you may need to rip down a lot of drywall to find it. Not bragging about leaks, but with mini-splits that can happen from time to time. With water, if a leak were to occur it will be immediately obvious and you will know where a leak is, as a few gallons will come out before the unit stops itself. Of course with a PEX system, there are rarely if ever leaks. With PEX piping, which is also commonly used for normal plumbing, you should not ever have a leak.
13. Ability to work with energy storage for cost-effective load shifting/peak shaving using low cost & unlimited charge-cycle water storage.
14. No special vented sealed risers needed for the lineset in multi-floor applications, no special code or safety issues.

Chiltrix also offers EVI units, in fact the Chiltrix EVI MAX unit has the highest officially-certified efficiency in the USA market for extreme cold climate heating. However, the extra cost and complexity of EVI is not always needed. If you are in a climate where a large part of your annual heating hours are below 25-30F there may be advantages to EVI. Please contact us for the ASHRAE Hourly Normals report for your nearest weather station, we can show you how many hours you will have per year at each temperature and help you make the best selection.

Once you have experienced the comfort and efficiency of in-floor heating, you may never again be satisfied with any other type of heating. Chiltrix is highly compatible with hydronic floor heating and is designed to deliver an optimum floor heating experience. Chiltrix can work  with in-floor radiant or radiant in walls or ceiling, or with radiant panels. And radiant can be used in combination with other means such as fan coils, air handlers, etc. The Chiltrix heat pumps are highly compatible with radiant.

We also have customers using the Chiltrix system for “radiant cooling” which works well when used with a dew point controller and may allow cooling to be added for little or no extra cost.

Like radiant heating, radiant cooling can be far more comfortable, increase indoor air quality, and can be the most efficient cooling choice available. Chiltrix is highly compatible with radiant cooling and produces a special radiant cooling controller that can ensure that the system works at maximum capacity while never producing a radiant surface below the dew point. Care must be taken in regards to dew point control, to prevent unwanted condensation. Please see more here about radiant cooling

There is no US DOE, EnergyStar, or other SEER test or rating for air-to-water heat pump chillers. AWHP units are rated under AHRI 550/590 which does not include SEER and are rated instead with IPLV. IPLV is to chillers what SEER is to standard air conditioners. It’s the official AHRI seasonal average efficiency rating and it’s the only rating that matters for heat pumps. IPLV is the industry-standard way of measuring the overall annual efficiency of a hydronic (chiller) cooling system. IPLV stands for Integrated Part Load Value, it’s a similar concept to SEER, where part-load performance is measured and rated so that customers can have a way to do an apples-to-apples comparison of real-world operating efficiency between various brands and models. IPLV and NPLV are specified in AHRI 550/590. See the product page or spec sheet for the IPLV / NPLV of the specific chiller. See a more complete explanation of IPLV

As with SEER, air-to-water heat pumps do not have a HSPF rating since HSPF is not available under AHRI 550/590. However, a Seasonal Average COP rating , called SCOP is available under IEC EN14825 and is essentially the same thing as HSPF. For example, the CX65 is also certified under EN14285 where it has a SCOP of 5.36, which converts to an equivalent HSPF 18.29. But note, this is not a HSPF rating, only an equivalent. See the details of HSPF vs. SCOP here.

Like all air conditioning systems, when the cooling coils are below the dew point, dehumidification is performed. The Chiltrix system performs very strong dehumidification comparable to a standard air conditioning system. And when used with DHC (Dynamic Humidity Control) the Chiltrix system can lower the coil temperature well below the standard condition to perform hyper-dehumidification and can also turn off dehumidification when not needed, to save energy.

The Psychrologix™ is a very unique and special controller. It is a programmable indoor controller that automates many features such as chiller reset, auto-changeover from cooling to heating, alarms, vacation mode, and many other features and includes the DHC (Dynamic Humidity Control) function. Note, this controller is not a thermostat, all thermostat functions are handled by the individual fan coil unit thermostats or in the case of ducted systems, by a standard thermostat. This controller has several functions, including DHC (Dynamic Humidity Control). Note that nearly all functions including DHC are now available free with the included heat pump controller.

The Chiltrix exclusive & patented DHC (Dynamic Humidity Control) automatically manages the Chiltrix heat pump cooling parameters to increase or decrease, or stop, dehumidification. If indoor humidity rises, the system can automatically decrease the coil temperature to a lower temperature so as to perform accelerated dehumidification. During times when humidity is within the ASHRAE recommended range, the DHC will reduce or  “turn off” dehumidification, allowing the system to continue to manage sensible (regular thermometer) temperature at a greatly reduced power consumption level. Indoor humidity occurs after an event such as an exterior door opening on a humid day, or taking a hot shower. Once removed, humidity will not quickly increase again until the next humidity event occurs. Chiltrix’s efficiency can increase up to 50% above its exceptionally high official EER ratings during periods when dehumidification is not needed.

The heat pump outdoor unit needs a stable mounting position like a concrete pad, a power connection, and insulated water lines connected to the indoor unit(s). Usually 1″ PEX flexible water lines are used for this. No refrigeration technician, gauges, extra refrigerant, or special tools are needed. Mainly, you need an electrician to provide a 208-240 50/60Hz power connection of >/= 15a (per ODU) and then make your water line connections. Any indoor units are powered separately using standard 120v household power. Other than that, you will install the water lines and may add a small expansion tank, some fittings, accessories, etc. per the manual and depending on the design.  Recommended for water lines is oxygen-free PEX which is available from Home Depot or Lowes, etc. Standard PEX can be used with X model Chiltrix heat pumps.

There are two ways that the Chiltrix chiller can work with solar, you can use either or both of these methods. The chiller can be integrated into a solar thermal/hydronic heating or solar water heating system and provide low cost heat at times when the sun is not available or when the load exceeds what the solar system can provide. X model Chiltrix heat pumps make this even easier. Secondly, the Chiltrix chillers are ideal for powering with off-grid or grid tied PV solar panels. It’s ideal because it uses much less power to operate than other similar sized air conditioners or heat pumps, and it has a “slow start” function that eliminates the initial in-rush surge of current. The unit starts at only <2 amps and slowly builds up, protecting batteries and inverters from sudden high amp surge loads. The unit requires AC power which can be supplied by an inverter.

Some locations may need backup heat, this will be known from the Manual J report. Integrated backup heat is another thing that makes Chiltrix unique  since the backup heat can be seamlessly incorporated into the system, avoiding, for example, the need for portable heaters. Like all heat pumps, heating capacity is reduced as outdoor weather gets colder. If you live in a very cold climate you may need backup heat occasionally. The globally-accepted way to add backup heat to a hydronic heat pump system is to use a normal water heater (like from Lowes or Home Depot) installed on the supply line. When backup heat is needed, the chiller can enable the tank heater that runs based on its own thermostat.

Chiltrix also offers an advanced, highly-efficient fully integrated backup heater, the V18. The V18 provides dynamically variable backup heat that precisely adds just the right amount of backup heat into the system based on the actual, real time capacity and load differential. Rather than chasing and overshooting a thermostat, the v18 receives communications from the Chiltrix heat pump to adjust power and exactly match any BTU shortfall in real time. 

ALL heat pumps, including Chiltrix, have reduced capacity at lower ambient temperatures. The factor that has the largest effect on efficiency, is the amount of “lift”, i.e., the delta T between the ambient and the heat pump operating outlet temperature. As ambient drops lower, the lift becomes higher. This is why Chiltrix helps design systems that can work properly with the lowest amount of lift. The advantages of lower lift is explained by the following Carnot calculation where (T¹- T²) is the amount of lift.

Chiltrix heat pumps do a great job of heating water, holding several US Department of Energy (EnergyGuide) records for the highest efficiency among all water heaters, including heat pumps. To provide DHW (Domestic Hot Water) the heat pump connects to a “heat exchanger tank” – this is also called an “indirect” hot water tank. It is a hot water tank with a heat exchanger coil inside. You will also use an electronic valve ordered from Chiltrix called a G valve (DHW valve). The chiller monitors the tank temperature using an included sensor. The chiller can temporarily switch from its normal cooling or heating function for a brief interval, to quickly heat the water tank whenever the tank needs heat. This is very advantageous, as water heated by the chiller can use up to 70% less energy than a standard electric water heater would use for the same amount of water heating.

A heat pump such as Chiltrix needs an “indirect” tank, such as a boiler tank or a solar tank, this is a tank with a coil inside. Of course we suggest our DHW105, DHW80, or DHW40 tanks as they are very high spec tanks made with duplex 2205 grade stainless steel and have an industry-leading over-sized coil with a very large surface area. And  there are many heat pump+ tank combinations that are DOE-certified with world record performance ratings. If you provide your own water heating tank, make sure of the following: it must have at least .35 ft^2 coil surface area per gallon, and, an inside diameter not less than 1″. And make sure it has a provision for a backup heating element so you can take full advantage of our automated anti-legionella function.

We don’t usually recommend recirculating hot water systems, in general, they waste electrical energy in order to save water and for most people the economics are better to not waste the energy. Also, the continuous parasitic load of recirc is not best for heat pump operation and can require adjustment or special design. We recognize that some customers, and certain local codes, require this. If you decide to use recirculating hot water with Chiltrix we suggest to only use it only with very well-insulated water lines. You may consider a “smart” recirc system such as those that have a “call” button or motion sensor, for example, AquaMotion. Chiltrix provides recommended designs for recirc systems here.

Yes, the Chiltrix air-to-water heat pump chillers can provide very low cost heating when compared to an electric, propane, or oil fired boiler. You can configure the chiller as primary and only run the boiler if needed with many programmable options as to the conditions when the boiler is allowed to operate, how it operates, etc.

Generally radiators are designed to receive very hot water, as high as 160-180F. No heat pump including Chiltrix will operate effectively at those temperatures. For example, if using Chiltrix at 105F with a radiator rated at 160F, the radiator capacity will be reduced to a factor around 37% of the original rating.One thing to note – often a radiator may run at a high temperature, but not really “need” this temperature if you notice that it only runs 30-40% of the time, in such case the same radiators may be able to heat the home by simply staying on longer at a lower temperature. It is suggested to reduce the current boiler temperature and see how low it can be set, while still meeting the coldest-day heating loads in order to see how applicable a heat pump may be. Often, radiators are replaced with fan coil units (which can also add a cooling capability). In many cases the existing piping can still be used, see this document that explains the various piping options.

It’s perfect, actually the original Chiltrix air-to-water chiller development started out as a successful effort to design the world’s most efficient air conditioner for small computer rooms/server rooms, actually it succeeded beyond our expectations. The server room version also has an available “free cooling” option that in cold weather, can allow the system to run at its full rated capacity with the compressor at reduced speed, or off, running only fans and water pump saving a large amount of energy cost without bringing in any outside air. Free cooling COP can be as high as 41 (EER 140) during cold weather periods. See more info on server rooms & free cooling. In addition, the stackable design of the Chiltrix system allows for a highly redundant N+N configuration.

The system is designed for global use and is therefore very flexible. It can use voltage between 208v to 240v, and can use either 50Hz or 60Hz power. Indoor Units (IDUs) are a little different – we offer 60Hz indoor fan coil units for 110v to 130v. We can also provide 220v IDUs that can run on 50Hz. So wherever you are and whatever kind of power you have, we have a solution.

The current generation Chiltrix units use R32a due to its higher efficiency and better operating characteristics. There are many reasons why, see the comparison of R32 to R454B document.

The CX34 standard included controller is all that most people would ever need. In addition, we offer the Psychrologix controller option for dynamic humidity control. Further, customers have the ability to control the CX34 by relays (such as from a standard single-stage heat pump thermostat). And for advanced users, we offer the (free) ability to control the CX34 via Modbus RTU (can be used also with BACnet gateway). We also have a Wifi control that can work from Android or iPhone.

Unlike chillers that have a cooling tower, the Chiltrix air-to-water heat pumps are air cooled like a regular air conditioner and such, only require the same periodic coil cleaning as would a standard AC/heat pump. It is a sealed outdoor appliance, there are no user-servicable parts inside, and no need for servicing. Any indoor fan/coil units need to have their filters removed, cleaned, and re-inserted on a regular basis. You can determine the frequency of this requirement based on the filters appearance (and your air quality).

The system is engineered using best-of-breed components sourced from top providers around the world. German brand Wilo VSD water pumps, USA valves, heat exchangers from (SWEP) Sweden and (Multi-Stack) Australia, electronics from Japan, Mitsubushi compressor (Japan) and Panasonic variable speed fan (Japan), and the list goes on. All components are selected based on reliability and performance. The system is easily serviceable and is designed for a 20 year lifetime.

The standard system is designed for low ambient heating and standard cooling. Heating is available from as low as at least  -13F or above, with some of our models like CX40 and CX65 operating to as low as -22F. See the detailed performance maps published for each of our units. For cooling, our T1 models (eg. cx35,cs50) can operate when outdor temperatures are as high as 120F. Our T3 rated units, (eg. CX40, CX65) operate in cooling at up to 131F outdoor temperature.

There is no refrigerant lineset needed or used with the Chiltrix self-contained chiller. All of the indoor units are connected to the chiller using standard insulated CPVC or PEX (or similar) water lines. The water line can be any length up to hundreds of feet. To calculate the actual distance we need to know the plumbing design and which indoor units are being used (so we can know the pressure drop spec). But regardless, an inexpensive Chiltrix-provided variable speed booster pump controlled by the chiller can provide a virtually unlimited allowable line distance, we have many installations where the heat pumps are >200 ft. away from the home.

The Chiltrix Limited Warranty is 5 years on the compressor and 2 years on other components. See warranty.

The unit is fully certified for USA and Canada and has obtained approval under UL 60335-2-40 and CSA 22.2. These certifications are recognized in over 90 countries worldwide. If you need other international certifications such as SAA, CB, CE, SONCAP, etc. we can provide any of these on quantity orders.

Further, the CX34 is AHRI-certified. AHRI is the official, independent 3rd party testing & certification organization used by the global HVAC industry and by government regulators worldwide. When AHRI certifies that a unit has a particular capacity or efficiency level, this certification is considered indisputable evidence that the performance stated by the manufacturer is accurate. Chiltrix units are also certified for Europe by TUV and  SGS where they hold an A+++ rating, the highest possible rating.

Chiltrix is also certified by the California Energy Commission (Titles 21, 24).

Please see the chiller heat pump air conditioner price list.

Whether it is used for a compressor, a pump, or a fan motor, DC Inverter motors are recognized as being more efficient, mainly because they use less power and can infinitely adjust their speed in real time to match the current demand. They also run cooler, last longer, and make far less noise.

DC Inverter motors actually have no inverter in them, this is a poor name that was applied years ago and has remained in use. Actually, AC power runs through a rectifier circuit converting it to DC power.

DC inverters are not only more efficient at a given speed, but having the ability to match the speed to the current application saves even more power.

We are Chiltrix Inc., a Virginia corporation established in 2015 and an affiliate under common control with HotSpot Energy Inc. (www.hotspotenergy.com). Chiltrix is distributed in North America by HotSpot Energy Inc.