Daikin SmartSource® Plus – Supplied & Professionally Installed by 4Most Energy
The Daikin SmartSource Plus is a horizontal water source heat pump designed for installations where the equipment is suspended above a ceiling or concealed behind an access panel. It is commonly used in offices, retail units, condominium-style buildings, and other spaces served by a building water loop.
The Plus series is available with either a single-stage WSMH compressor or two-stage WSNH compressor. WSMH models cover ½–5 tons, while WSNH models cover 2–5 tons. The system uses R-32 A2L low-GWP refrigerant and can be configured with optional hot gas reheat dehumidification on sizes 015–060.
Installation requires more than simply replacing the equipment. 4Most Energy evaluates the existing water loop, entering water temperatures, water flow, ductwork, electrical service, ceiling access, condensate drainage, and available equipment configuration before ordering the replacement.
Water connections require appropriate isolation and filtration components, while the condensate system must be properly trapped and drained. Electrical work must match the selected model's voltage and phase requirements. Where the equipment is concealed above a ceiling, safe access and equipment support are also required.
Correct sizing is based on the served zone's load, occupancy, glazing and exposure, ductwork airflow capability, and water-loop conditions. A replacement should not automatically be matched to the nameplate of an older unit because previous equipment may have been oversized.
For spaces experiencing persistent humidity problems, the optional hot gas reheat configuration should be evaluated during sizing.
Model Comparison Specifications
| Specification | WSMH | WSNH |
|---|---|---|
| Compressor | Single-stage | Two-stage |
| Capacity Range | ½–5 ton / 7,000–60,000 Btuh | 2–5 ton / 24,000–60,000 Btuh |
| Available Sizes | 007–060 | 024–060 |
| Refrigerant | R-32 A2L | R-32 A2L |
| Fan Motor | PSC standard; ECM optional on 015–060 | PSC standard; ECM optional on 015–060 |
| Approx. Weight | 104–306 lb | 212–306 lb |
Warranty
Daikin Applied backs every SmartSource Plus unit with a standard 12-month parts warranty from start-up (or 18 months from ship date, whichever occurs first). Extended coverage — up to 4 years on the compressor, refrigerant circuit, or complete unit, with optional first-year or 5-year labor allowances — is available at the time of purchase. 4Most Energy handles warranty registration and the required Check, Test & Start documentation on your behalf.
PLUS HORIZONTAL Specifications
| Model | Depth | Width | Height | EER | COP |
|---|---|---|---|---|---|
| WSMH007 | 19.00" | 40.00" | 11.50" | 16.1 | 5.6 |
| WSMH009 | 19.00" | 40.00" | 11.50" | 13.5 | 4.7 |
| WSMH012 | 19.00" | 40.00" | 11.50" | 14.5 | 4.6 |
| WSMH015 | 19.00" | 43.00" | 17.30" | 17.8 | 5.9 |
| WSMH019 | 19.00" | 43.00" | 17.30" | 17.0 | 5.2 |
| WSMH024 | 21.50" | 49.00" | 19.00" | 17.5 | 5.6 |
| WSMH030 | 21.50" | 49.00" | 19.00" | 17.6 | 5.7 |
| WSMH036 | 24.00" | 54.00" | 19.00" | 17.2 | 5.4 |
| WSMH042 | 24.00" | 54.00" | 19.00" | 17.0 | 5.4 |
| WSMH048 | 24.00" | 65.00" | 21.00" | 16.2 | 5.2 |
| WSMH060 | 24.00" | 65.00" | 21.00" | 15.3 | 4.8 |
Why Install the Daikin SmartSource Plus with 4Most Energy?
- R-32 low-GWP refrigerant with a listed GWP of 675 compared with 2,088 for R-410A.
- Optional hot gas reheat dehumidification on sizes 015–060 for improved humidity control without excessive space overcooling.
- Single-stage WSMH or two-stage WSNH compressor configurations depending on application requirements.
- ECM constant-CFM fan motor option on sizes 015–060.
- MicroTech® unit controller with LED annunciator sight glass and optional BACnet® communication.
- Convertible discharge configuration with field rotation of the fan assembly for straight or end discharge.
- Waterside economizer option for free cooling when water-loop temperatures permit.
- Six designer cabinet finishes in addition to standard galvanized construction.
- Copper inner-tube heat exchanger standard, with cupronickel available as an option.
- Multiple filtration configurations, including 1" disposable, 2" MERV 8, and 4" MERV 13.
| Parameter | Specification |
|---|---|
| Refrigerant | R-32 (A2L, low-GWP) |
| Heat Exchanger | Copper inner tube standard; cupronickel optional |
| Dehumidification | Simplified dehumidification standard; hot gas reheat optional on 015–060 |
| Minimum Water Flow | 1.5 GPM/ton |
| Nominal Water Flow | 3.0 GPM/ton |
| Maximum Water Flow | 4.0 GPM/ton |
| Standard Entering Water Temperature – Cooling | 55°F–120°F |
| Standard Entering Water Temperature – Heating | 55°F–90°F |
| Extended Entering Water Temperature – Cooling | 30°F–120°F |
| Extended Entering Water Temperature – Heating | 25°F–90°F |
| Controller | MicroTech® |
| BACnet | Optional |
| Filtration | 1" disposable, 2" MERV 8, or 4" MERV 13 |
| Cabinet | Galvanized standard; six designer finishes available |
| Certifications | AHRI Certified (ISO 13256-1); ETL/Intertek Listed |
| Electrical | Model-dependent; see voltage options below |
Sizing Guide
SmartSource Plus units are sized by nominal cooling capacity (sizes 007 through 060, corresponding to ½ through 5 tons). Correct sizing depends on the served zone's square footage, glazing/exposure, occupancy, and the existing ductwork's airflow capacity — not simply matching the nameplate of the unit being removed, since older Carrier, Keeprite, Lennox, and McQuay units were sometimes oversized by the standards of their era. If the space has a history of humidity complaints (common in retail fitting rooms, below-grade units, or spaces with high outside-air infiltration), the hot gas reheat option should be evaluated during sizing.
4Most Energy performs a load calculation and ductwork/water flow verification as part of every quote to confirm the correct size and configuration before ordering.
1. Request Installation Quote Provide the existing equipment model and photos of the unit, ceiling access, and nameplate where available.
2. System Sizing Consultation We evaluate the existing equipment, served space, water loop, ductwork, electrical service, and humidity requirements.
3. Equipment Recommendation We confirm the appropriate WSMH or WSNH model, capacity, voltage, configuration, and available options.
4. Installation Scheduling Once the equipment and installation scope are confirmed, the replacement is scheduled.
5. Removal of Existing Equipment The existing unit is isolated, disconnected, and removed. Refrigerant recovery is completed where applicable.
6. Installation & System Connection The new unit is mounted and connected to the water loop, ductwork, condensate system, and electrical service.
7. Safety Testing Electrical connections, water flow, condensate drainage, refrigerant circuit operation, and system controls are checked.
8. Final Commissioning The system is commissioned and operating conditions are verified before completion.
Standard warranty: 12 months parts from start-up or 18 months from ship date, whichever occurs first. Extended warranty options (1-year or 4-year, on compressor only, refrigerant circuit, or complete unit, with optional labor allowances) are available at purchase — 4Most Energy will review the right level of coverage for your building's usage profile.
Ongoing maintenance is minimal: motors are permanently lubricated and require no oiling. Filters should be checked every 60 days initially and adjusted to your building's actual lint/dust load thereafter; the condensate drain pan should be inspected and flushed annually; and strainers on the water loop connection should be inspected regularly.
Units with the hot gas reheat option should have the reheat coil and humidistat checked during annual service.
4Most Energy offers scheduled maintenance plans that cover filter changes, condensate pan cleaning, refrigerant circuit checks, and annual performance logging.
Service Area
Greater Toronto Area (GTA) and surrounding regions
Toronto, Markham, Richmond Hill, Vaughan, Aurora, Newmarket, Scarborough, Brampton, and Mississauga.
Extended Service Area: Stouffville, Oshawa, Barrie, Orangeville, Hamilton, St. Catharines, Guelph, Kitchener.
Frequently Asked Questions
How do I know if I even have this type of unit?
Look for a removable ceiling tile or small access panel with no visible equipment in the room — just a grille or duct register. If a technician has ever opened that panel to change a filter, that's this unit. It's the standard equipment type in office buildings, retail spaces, and condominium-style commercial buildings, and it's also common behind the ceiling in individual condo suites. Send us a photo if you're not sure.
Is the SmartSource Plus a direct replacement for my existing Carrier, Keeprite, Lennox, McQuay, or Daikin unit?
In most cases, yes — the horizontal ceiling-suspended footprint, duct collar locations, and water connections are compatible with standard retrofit practice, though 4Most Energy always verifies exact dimensions and cabinet hand/discharge configuration before ordering.
Can 4Most Energy just repair my existing unit instead of replacing it?
Yes. We service and repair existing water source heat pumps of any brand, not only Daikin. If your unit is fixable and doesn't need full replacement, we'll tell you that upfront rather than push a new install.
Will you need to cut open my ceiling to do the work?
Yes, for a replacement or new install — the unit sits above the ceiling, so we open a tile or cut a drywall access panel, bring in a lift to safely support the equipment, and close, patch, and paint the opening to match your ceiling before we leave. Repairs on an existing unit sometimes only need the existing access panel opened, with no patching required.
When does the hot gas reheat option make sense?
It's worth the upgrade for spaces with persistent humidity complaints, high latent loads (retail with heavy foot traffic, spaces with significant outside air), or where overcooling during dehumidification cycles has been an issue with the previous unit.
What's the difference between the single-stage WSMH and two-stage WSNH?
The WSNH's two-stage compressor better matches part-load conditions, reducing cycling and improving comfort and efficiency versus the single-stage WSMH, at a modest cost premium.
Can I match the unit's cabinet color to my building's finishes?
Yes — the Plus tier offers six designer color finishes in addition to standard galvanized, useful where the unit's cabinet face is visible in a finished space.
How long does a typical unit replacement take?
Most single-unit horizontal WSHP replacements in occupied condo or office space, including ceiling patch and paint, are completed in a single day, minimizing disruption to the tenant.
Horizontal Heat Pump
