Buying heat-recovery ventilation from China
Have your UK ventilation designer approve the exact unit within a complete house design: duct routes and resistance, room airflow targets and supply/extract balance, condensate drainage, service access and the commissioning plan. Obtain written acceptance before ordering. Factory documents can be gathered by Cambridge China Bridge.
Agree the design brief and approval scope
Ask your designer to record the property's UK nation, layout, occupancy assumptions, airtightness information and whether the work concerns a new or existing dwelling. Have them identify the applicable ventilation guidance and edition. England's Approved Document F has different editions for different project circumstances; earlier versions continue to apply to buildings subject to previous regulatory standards.
Obtain written acceptance of the exact unit, controls and installation drawings before releasing the order. Treat this as a purchasing safeguard. Our extractor-fan guide covers basic extraction checks; this guide adds the approval questions for a complete supply-and-extract system. Keep separate product-document checks in the electrical imports guide.
Approve the complete duct network
Request coordinated drawings showing supply and extract branches, duct sizes, fittings, manifolds, silencers, terminals and outdoor intake and exhaust positions. Have the designer assess resistance along the critical routes and select the unit using its airflow-versus-pressure curves. Include filters and accessories in that assessment, with an agreed allowance for filter loading.
Ask the designer to resolve noise, draughts, intake contamination, exhaust recirculation and any fire-sensitive penetrations. Specify duct supports, joint sealing, insulation and vapour sealing where appropriate. Record the accepted component schedule and drawings in your product specification. A factory duct kit should follow the accepted design rather than determine it.
Approve room airflow and system balance
Ask for a room schedule identifying supply and extract terminals, normal and boost airflow targets, and the intended whole-house supply/extract balance. Have the designer specify the acceptable balance and measurement method for the applicable project. Matching fan speed settings does not establish matching airflow through different duct networks.
Have the designer show how air moves between rooms with doors closed and account for cooker extraction, other fans and combustion appliances. Agree accessible balancing points, boost controls and how frost protection or summer bypass affects operation. Require the factory to provide control descriptions so the designer can assess these operating modes before selecting the unit.
Approve condensate drainage and cold-space details
Obtain the exact model's condensate outlet drawing and permitted installation orientation. Ask the designer and installer to agree the drain route, fall, trap or specified alternative, discharge connection and access for clearing blockages. Check compatibility with the unit's pressure conditions and instructions. Do not assume a supplied hose completes the drainage design.
Ask them to assess freezing, leakage and condensation risks around the unit and ducts, including unheated spaces. Agree insulation and vapour-seal details, supports and any protection needed at the discharge. Include a site drainage check in the acceptance plan and specify who corrects leaks, pooling or an unsuitable discharge arrangement.
Prove that maintenance is physically possible
England's dwelling ventilation guidance says adequate space should be available to maintain ventilation equipment. Request a drawing showing the actual space needed to open covers, withdraw filters and the heat exchanger, reach fans and service the drain. Check this against finished ceilings, cupboards and access hatches, rather than the unit's outer dimensions alone.
Ask how ducts and terminals will be cleaned and how the unit could be removed for repair. Obtain filter specifications, replacement-part references and operating and maintenance instructions in English. Agree the maintenance schedule from the selected equipment's instructions. Have the intended installer accept the arrangement through the construction submittal guide.
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Agree commissioning evidence before ordering
Ask your designer to confirm how England's dwelling ventilation guidance applies to commissioning the system to provide adequate ventilation, including any notice required by building control, and name the person responsible. For other UK nations, agree the applicable local commissioning and submission arrangements.
Specify a signed handover record comparing design and measured airflow at every supply and extract terminal, with totals, balance, operating modes, final settings, test conditions and instrument calibration evidence. Include control, drainage and access checks, final drawings and user instructions. Agree responsibility for correction and retesting. Factory performance reports support selection; they cannot establish the completed house system's performance.
Frequently asked questions
Can I order a Chinese heat-recovery unit before duct design?
Obtain designer acceptance first. Unit selection depends on the room airflow targets, complete duct resistance, controls, drainage and available service space.
Do equal fan settings mean balanced ventilation?
No. Supply and extract routes can have different resistance. Ask for measured room airflow and total supply/extract balance against the accepted design.
Does a heat-recovery unit need a condensate drain?
Ask your designer to approve the exact model's drainage arrangement using its instructions, including the outlet, trap arrangement, discharge, frost risk and clearing access.
What commissioning proof should I request?
Request signed terminal airflow results, totals and balance, final settings, control checks, drainage checks, calibration evidence and user instructions. Agree the applicable building-control submission with your designer.