Water Tank and Booster Pump Sizing for Apartment Buildings Up to 6 Storeys

A 6-storey apartment building usually needs two things working together: a water tank sized to actual demand and a booster pump or panel sized to deliver that water at usable pressure to the top floor. Sizing the tank by floor count alone is a common mistake. The volume should be based on the number of units and occupants, the fixture count per unit, and any fire reserve required under local code, not an assumption tied to the number of storeys. A 6-storey building with 40 small units and a 6-storey building with 12 large units will need very different tank capacities even though both are 6 storeys. JOHOB supplies FRP, GRP, hot-dip galvanized (HDG), and stainless steel modular tanks through its sister brand TankSmith, in configurations that fit a rooftop deck or a confined ground-level pad, which is the usual constraint on a mid-rise apartment lot. Because an exact tank size depends on occupant count, fixture count, and whether a fire reserve applies, the accurate number for a specific building comes from an RFQ, not a blanket figure. JOHOB responds to sizing requests within 1 business day, and quotes are prepared against the submitted occupancy and fixture data rather than floor count alone.

Tank capacity and booster pump capacity are two separate calculations, and sizing one does not size the other. The booster set is sized against peak instantaneous flow, the combined draw expected when multiple units pull water at the same time, and against total dynamic head (TDH), the vertical lift to the highest fixture plus friction losses through the riser. A 6-storey building sits in a size range where a duplex (two-pump) set or a VFD-controlled panel is the usual choice over a single pump, since duplex and VFD configurations keep pressure constant as demand on the building changes through the day and give a standby pump if one unit needs servicing. This matters more for an occupied apartment building than for a single-family connection, because a pressure drop affects every tenant on the upper floors at once, not just one household. JOHOB supplies VFD, SDE (soft start), star-delta, and MCC panels built around the pump duty point, with CE marking on the electrical equipment and ISO 9001 certification on the manufacturer's quality system. As with tank sizing, the exact HP, head, and panel configuration for a given 6-storey building depends on unit count, fixture count, and riser layout, and JOHOB prepares that calculation as part of the RFQ response rather than publishing a single HP figure that would not fit every building.

Tank material choice affects weight, installation access, and long-term maintenance, all of which matter more on a 6-storey apartment lot than on an open industrial site. FRP (fiberglass reinforced plastic) and GRP (glass reinforced plastic) modular tanks are lightweight and assemble in panels, which suits rooftop placement where a crane lift of a single large tank is not practical. HDG (hot-dip galvanized) steel modular tanks are a heavier, more impact-resistant option for ground-level cisterns. Stainless steel tanks cost more but need the least maintenance over the life of the building. JOHOB supplies all four tank types through its sister brand TankSmith, with WRAS-certified panels on the tank line and ISO 9001 certification on the manufacturer's quality management system. Because an apartment building's rooftop access and load limits vary by project, the right material is confirmed against the specific site rather than assumed from the storey count alone.

Reliable water pressure on the top floor of a 6-storey building depends as much on the control panel as on the pump itself. A VFD (variable frequency drive) panel ramps pump speed up and down to match actual demand, which holds pressure steady instead of the on-off surges a simple pressure switch produces, and it reduces wear on the motor and the piping. A duplex panel pairs two pumps so one can run while the other is serviced, which matters on an occupied residential building where water cannot be shut off for a repair without notice. JOHOB's panels are built around MCC (motor control center), star-delta, and SDE configurations depending on the duty point and are supplied with CE marking on the electrical equipment. ASME standards apply where the system includes pressure vessels. Buyers comparing panels for an apartment building should ask for the duty point calculation (flow, head, kW) behind the panel spec, not just a horsepower number, since the same HP rating can be wired into very different control configurations.

Before buying a tank, pump, or panel for an apartment building, confirm the certifications on the actual equipment being quoted, not just the supplier's general claims. Check for ISO 9001 certification on the manufacturer's quality management system, TUV SUD testing on the equipment, CE marking on electrical and material handling components, WRAS certification on tank panels, and ASME compliance where the system includes pressure vessels. These are the certifications on JOHOB's supplied equipment. None of them substitute for a local permit or a licensed contractor's sign-off on the installation itself, and JOHOB does not claim any installation-specific licensing, so confirm that separately with your chosen installer. If a quote references a license or accreditation for the installation work rather than the equipment, verify that claim directly with the contractor, since equipment certification and installation licensing are two different things.

JOHOB prices tank, pump, and panel packages on a quote basis since equipment specification varies by building, and does not publish fixed prices for apartment-scale systems. Standard lead times are 21 to 35 days for ex-stock equipment and 45 to 90 days for made-to-order configurations, so a building team planning around a specific move-in or occupancy date should request a quote early enough to cover that window. A 12% VAT applies to VAT-registered buyers; PEZA and SBMA locators and qualified exporters receive zero-VAT treatment on eligible purchases. JOHOB covers NCR, the rest of Luzon, Visayas, and Mindanao, including PEZA, SBMA, and Clark zone deliveries, and responds to RFQs within 1 business day. For an apartment building project, the fastest path to an accurate quote is to submit unit count, fixture count per unit, available tank footprint (rooftop or ground), and target occupancy date in the same RFQ.