1894 PVC Vent to R-454B Projects | Purisync Kirkwood
Project Gallery
The projects below run the range of what west St. Louis County HVAC actually looks like: a 1894 Meramec Highlands shingle-style cottage that needed PVC sidewall venting because its original unlined masonry chimney couldn’t carry a 95% AFUE flue. A 2,400-square-foot dental office on Manchester Road that needed economizer-equipped commercial RTU replacement sized to ASHRAE 62.1 patient ventilation. A 1956 Craig Woods mid-century ranch where the existing 6×10 trunk ducts were strangling a new variable-speed blower. Each photo is paired with the technical decision behind it. Equipment selection isn’t a catalog pick — it’s a Manual J load, a static pressure budget, a refrigerant-transition deadline, and a Spire gas pressure verification, all at once.
Furnace Installations and Retrofits
Meramec Highlands — Magnolia Avenue, 1894 shingle-style cottage. Carrier 59MN7A 96% AFUE modulating furnace, 60,000 BTU/hr, replaced original 80% AFUE upflow. Existing unlined masonry chimney could not carry a category IV condensing flue. PVC concentric sidewall vent through south-facing brick wall, 3″ diameter, 14-foot equivalent length, terminating 18″ above grade with snow shield. Manual J load: 58,000 BTU/hr at -5°F design temp. Spire gas pressure verified at 7.2″ WC at meter, 3.5″ WC at manifold post-regulator.Webster Groves — Big Bend Boulevard, 1923 Craftsman bungalow. Trane S9V2 two-stage 96% AFUE furnace with TruComfort variable-speed ECM blower. Existing 6×10 supply trunks replaced with 8×14 to bring total external static under 0.5″ WC. Original gravity furnace octopus removed from basement. New return drop fabricated through joist bay between kitchen and dining room. Kirkwood Public Works permit #KW-2025-04287, inspected and closed.Town and Country — Clayton Road residence, 2018 new construction, 4,200 sq ft. Carrier Infinity 98 modulating furnace, 100,000 BTU/hr, paired with Infinity zone control board running four zones: main floor north, main floor south, second floor master, second floor bedrooms. Manual J load split: zone 1 28,000 BTU/hr, zone 2 24,000 BTU/hr, zone 3 18,000 BTU/hr, zone 4 22,000 BTU/hr. Bypass damper with static pressure sensor. Permitted through St. Louis County.
Air Conditioning Installations
Affton — Gravois Road area, 1962 ranch home, 1,650 sq ft. Lennox SL18XC1 R-454B condenser, 3-ton, paired with existing N-coil after refrigerant compatibility verification. Line set flushed with Nu-Calgon Rx11-Flush, sized 3/8″ liquid and 7/8″ suction for 45-foot equivalent run. Condenser placement analyzed for afternoon shade from a 60-year-old pin oak — measured ambient at the unit 4°F lower than the airport NWS station at 3 p.m. on a 94°F design day. Concrete pad with ACCA 1006-2024 tornado tie-down anchors.Crestwood — Watson Road area, 1978 split-level, 2,100 sq ft. Bryant Evolution 187B Extreme R-454B condenser, 3.5-ton, with new R-454B-rated line set replacing original R-22 copper. Complete refrigerant retrofit: existing copper removed (32 feet, 3/8″ liquid and 7/8″ suction), new copper run with mechanical compression fittings at the air handler connection, evacuated to 250 microns, charged by superheat on TXV-equipped evaporator. SEER2 rated 17.5.
Heat Pump Conversions
Sugar Creek — 1955 mid-century ranch, 1,800 sq ft, no natural gas service. Mitsubishi Hyper-Heat MUZ-FH18NA outdoor unit paired with MSZ-FH18NA wall-mount indoor head as primary, plus three additional indoor heads in zoned configuration. Rated 100% capacity at 5°F outdoor temperature — sized to Climate Zone 4A heating load with no auxiliary electric resistance backup required above 5°F. Existing electric baseboard removed. SEER 22.0, HSPF 13.5.Meacham Park — small ranch, 1,200 sq ft, prior electric forced-air system. Daikin Aurora RXTQ36TAVJUA outdoor unit, 3-ton variable capacity, paired with FTXR18 indoor cassette. Replaced 1990s electric resistance system that was producing $340 February utility bills. Projected annual heating cost reduction: 58%. Daikin 12-year parts and labor warranty registered.
Ductwork Retrofits and IAQ
Jefferson-Argonne — 1898 home, complete supply and return ductwork retrofit. Original 5×10 supply trunks running through a single 18-foot crawl space replaced with 8×14 mains, with takeoffs sized per ACCA Manual D for 0.05 inches WC per 100 feet of equivalent length friction rate. New return air drop fabricated through stair stringer chase. Existing knob-and-tube wiring re-routed by licensed electrician before duct work began. Static pressure post-install: 0.38″ WC total external static at high-stage blower speed.Town and Country — 2021 new construction, 3,800 sq ft tight envelope. Aprilaire 8126X energy recovery ventilator installed with dedicated 6″ supply and return ducts, sized to provide 0.35 air changes per hour continuous ventilation per ASHRAE 62.2-2022. Stale air pickup at master bath and laundry; fresh air supply to main living areas. CO2 sensor at thermostat triggers boost mode above 1,000 ppm. Whole-home MERV 16 filtration upstream of the ERV.
Commercial Projects
Manchester Road — 2,400 sq ft dental office. Bryant 580J rooftop unit, 7.5-ton, replacing 13-year-old Carrier package unit. Economizer configured for free cooling below 65°F outdoor temp. Outdoor air ventilation sized to ASHRAE 62.1-2022 patient occupancy load: 15 cfm/person at 6 chairs plus 5 staff. Curb adapter fabricated for slight footprint mismatch. August utility bill dropped 22% year-over-year.Sappington — 12,000 sq ft light industrial / warehouse facility. Annual service contract covering four Carrier 50TC rooftop units, 7.5-ton each. Spring and fall PMs include coil cleaning, belt tension verification, condensate drain treatment, refrigerant charge by subcooling, electrical inspection of contactors and capacitors, and Spire gas pressure verification on the gas-fired heat sections. One unit replaced under contract in year three after compressor lockout from a failed crankcase heater — covered under unit warranty, labor billed at contract rate.
Emergency Repairs
Meramec Highlands — January 2024 Polar Vortex, no-heat call at -2°F outdoor. 11-year-old Carrier Infinity 96 furnace locked out on pressure switch. Diagnosis: stuck pressure switch from ice buildup in the inducer condensate drain trap. The previous contractor had condemned the heat exchanger over a non-existent crack and quoted $9,800 for replacement. Borescope inspection of secondary heat exchanger confirmed no cracks, no carbon scoring. Pressure switch replaced ($28 part) and inducer drain re-routed with proper trap and trace heat. Total repair: $142 in parts and one hour of labor at 5:20 a.m.Webster Groves — July 2024 heatwave, no-cooling call at 94°F outdoor, 78°F coincident wet bulb. 12-year-old Trane XR15 condenser tripping breaker on startup. Diagnosis: capacitor measuring 8 microfarads on a 35 microfarad rated component. Single-phase compressor starter capacitor replaced ($45 part), contactor inspected and cleaned. Refrigerant charge verified by subcooling (8°F target, measured 7°F). System running within manufacturer spec by 11:45 a.m., 90 minutes after the call.
What the Gallery Doesn’t Show
Every project gets paired with a Manual J load calculation worksheet, a Manual S equipment selection PDF, photos of the existing condition before work began, photos of the install in progress, photos of the completed system, and a digital combustion analysis report for any gas-fired equipment. The customer keeps a copy. The municipal inspector keeps a copy. We keep a copy. None of that paperwork makes the gallery photos — but it’s why the gallery photos are what they are.
Frequently Asked Questions
What kinds of HVAC projects does Purisync show in the gallery?
Furnace installations and retrofits (including historic district homes with PVC sidewall venting requirements), R-454B air conditioning installations and refrigerant transitions from R-22 and R-410A systems, heat pump conversions for homes without natural gas service, ductwork retrofits in pre-1940 housing, indoor air quality projects including ERV installation in tight new-construction envelopes, commercial rooftop unit replacements with ASHRAE 62.1-compliant economizer ventilation, and emergency repair documentation showing diagnosis before quoting.
Do you work on historic homes in Kirkwood’s designated districts?
Yes. We have completed work in every designated Kirkwood historic district: Meramec Highlands (1890s), Central Place (1920s), Jefferson-Argonne (1850s–1950s), Savoy (early 1950s), Craig Woods (mid-1950s mid-century modern), North Taylor, West Argonne, Barrett Brae, and Sugar Creek Ranch. Historic district installations require attention to unlined masonry chimneys (PVC sidewall venting on 90%+ AFUE equipment), undersized original ductwork (replacement to meet 0.5″ WC static pressure budgets), and the Kirkwood Landmarks Commission design guidelines for exterior modifications including condenser placement.
Can I request a similar project quote based on what I see?
Yes, but the quote will start with a Manual J load calculation on your specific home, not a comparison to a photo. A 1,800 sq ft Jefferson-Argonne home from 1898 with original windows can carry a 65,000 BTU/hr heating load and 32,000 BTU/hr cooling load. A 1,800 sq ft Town and Country home from 2018 with triple-pane windows might carry 28,000 BTU/hr heating and 24,000 BTU/hr cooling. Equipment selection follows the load, not the photo.
What sizing methodology do you use on the projects shown?
ACCA Manual J for whole-house heating and cooling load calculation, Manual S for equipment selection matching the calculated load, Manual D for duct system verification when existing ductwork is staying or new duct runs are required. Zoned systems get a per-zone Manual J. Commercial rooftop unit sizing follows ASHRAE 62.1 for ventilation outdoor air requirements based on occupancy and use category. Refrigerant charge verification is by subcooling on TXV-equipped systems and superheat on piston-equipped systems.
How long do typical residential installations take?
A straight furnace and condenser replacement on existing compatible ductwork: one full day, typically 8–10 hours, with the homeowner having heat or cooling restored by evening. A complete system replacement including duct retrofit in a historic district home: 3–5 days. A new heat pump install with refrigerant line set replacement and electrical service modifications: 2 days. A zoned multi-stage installation in new construction: 3–4 days. Every project includes permit pull, inspection scheduling, and warranty registration in addition to the install itself.
Contact Purisync Heating and Air
Our 325 N Kirkwood Road office is a half-mile from the I-44 and I-270 interchange. Every project in this gallery was permitted, inspected, and warranty-registered. Whether you’re looking at a 1894 Meramec Highlands cottage that needs PVC sidewall venting, a 1956 Craig Woods ranch that needs duct retrofit before a modern variable-speed blower will work, or a 2018 Town and Country tight-envelope build that needs ERV-integrated ventilation, every project starts with a Manual J load calculation, not a sales quote.
