EQUIPMENT / EQUIPMENT FAMILY

Dunham-Bush ACTSXHP-R · Non-reversing defrost and radiator duty

Specify heating output during defrost at the actual climate and radiator temperatures, with a measurable water-temperature criterion.

From Dunham-Bush (China) Industrial Co., Ltd.

Individual product research · HVACDeck Editorial · Sources checked 2026-10-11

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Manufacturer catalogue image · ACTSXHP-R

01 / UNDERSTAND THE EQUIPMENT

Select continuous heating with an issued winter and defrost schedule

ACTSXHP-R is Dunham-Bush's non-reversing-defrost low-temperature air-source heating family. The official page publishes 235–560 kW heating and describes continuing heating without changing to cooling mode during defrost. Its actual features include 50–99.99% capacity regulation, electronic expansion control, an economizer, horizontal packed oil separation and oil cooling. The original rendering shows an outdoor integrated assembly, not an issued installation or selected rating.

The manufacturer positions the family for northern-climate district heating and existing radiator retrofits, and advertises service to 4000–10000 m². That area is not a transferable building design value: no heat-loss calculation, ambient/water rating or defrost test was inspected. The source says water-temperature fluctuation is small but provides no numerical tolerance or transient trace. A useful selection must establish the actual low-ambient heating curve and defrost duty together with radiator temperatures, system water volume and backup heat. R134a and a seven-inch Chinese touchscreen/RS485 MODBUS interface are named features.

02 / READ THE CONDITIONS

Published parameters and their scope

This is an equipment family; its range does not identify one orderable configuration.

Family designation: ACTSXHP-R

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Manufacturer-published values · conditions are part of the specification
Parameter	Published value	Conditions and evidence
Published heating range	235–560 kW	No simultaneous ambient/water selected rating issued. Source
Defrost description	Non-reversing; heating continues without switching to cooling	No inspected output/transient test or patent scope. Source
Capacity-control claim	50–99.99%	Supplier range; selected minimum-load map needed. Source
Refrigerant/oil features	R134a; packed oil separator and oil cooling	Selected charge/service circuit required. Source
Control interface	7-inch Chinese touchscreen; RS485/open MODBUS	Actual registers and ordered custom programme needed. Source
Area/comfort claims	4000–10000 m²; small water-temperature fluctuations	No project heat-loss or numerical defrost tolerance provided. Source

Selection and application review

Replace area-based sizing with the building heat-loss file

Issue design climate, actual heat losses, radiator supply/return temperatures and the demand profile. Obtain selected heating capacity/input at those simultaneous conditions, including cold-weather operation. The advertised floor-area range cannot size a particular old building or prove boiler replacement capacity.

Define warm-up demand, backup heat and permitted room/water-temperature variation. Existing radiator systems require their actual hydraulic and temperature requirements to be included in the selection, rather than assuming the heat pump matches the old boiler's output.

Require a measurable non-reversing-defrost result

Request the actual defrost circuit/sequence, trigger and termination logic, heating output during defrost and a water-temperature trace at specified ambient conditions. The source says heating continues and fluctuations are small, but supplies no guaranteed deviation or duration.

Agree the allowable transient and recovery time with actual system water volume and load. Do not infer full nominal heating output throughout every defrost event or a verified patent from the supplier's patent-style description. Confirm what happens if a defrost cycle fails to complete.

Approve the hydraulic and oil-protection installation

Obtain minimum/maximum water flow, pressure drops, pump/valve responsibilities, freeze protection and installation clearances. The outdoor integrated rendering does not establish foundation loads, connection dimensions or sound performance.

Request the selected oil-separation/cooling and economizer arrangement, inspection access and protective states. Electronic expansion and capacity-regulation wording does not supply actual setpoints or stable low-load limits. Include power-loss and restart behaviour in the issued design.

Commission actual controls and winter acceptance

Freeze the Chinese-interface operating documentation, MODBUS register list, alarm priorities and any custom programme. Timed operation and numerous protection functions do not alone establish safe unattended operation for the whole heating site. Assign supervisory and emergency-response responsibilities.

Acceptance should measure selected heating duty/input, water temperatures, defrost transition/recovery, flow protection and installed communications. Current price, lead time, independently verified savings and the exact selected warranty are unknown.

Issue radiator and climate duty
Obtain heat loss, water temperatures, load profile and backup requirements.
Approve defrost evidence
Require actual output, duration, temperature trace and recovery criteria.
Witness winter operation
Verify hydraulic protections, defrost/control states and measured useful heat.

Sources and review scope

Compiled by HVACDeck Editorial. Source review identifies what the publication states; it is not an independent performance test or certification.

Official ACTSXHP-R non-reversing-defrost pageChecked 2026-10-11 · Complete range, defrost/oil/control descriptions read; original outdoor assembly rendering inspected. Area and comfort claims not adopted as project ratings.

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