diff --git a/src/specificClass.js b/src/specificClass.js
index dd826b4..9e421d5 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -11,7 +11,7 @@
 
 'use strict';
 
-const { BaseDomain, UnitPolicy, POSITIONS, interpolation, convert } = require('generalFunctions');
+const { BaseDomain, UnitPolicy, POSITIONS, interpolation } = require('generalFunctions');
 const GroupOperatingPoint = require('./groupOps/groupOperatingPoint');
 const groupCurves = require('./groupOps/groupCurves');
 const TotalsCalculator = require('./totals/totalsCalculator');
@@ -383,7 +383,7 @@ class MachineGroup extends BaseDomain {
                 v, 0, 100, dt.flow.min, dt.flow.max);
         } else {
             try {
-                canonical = convert(v).from(unit).to('m3/s');
+                canonical = this.unitPolicy.convert(v, unit, 'm3/s', 'setDemand absolute flow');
             } catch (err) {
                 this.logger?.error?.(`setDemand: cannot convert ${v} ${unit} -> m3/s: ${err?.message || err}`);
                 return undefined;
@@ -446,10 +446,12 @@ class MachineGroup extends BaseDomain {
     }
 
     _canonicalToOutputFlow(value) {
-        const from = this.unitPolicy.canonical.flow;
-        const to = this.unitPolicy.output.flow;
-        if (!from || !to || from === to) return value;
-        return convert(value).from(from).to(to);
+        return this.unitPolicy.convert(
+            value,
+            this.unitPolicy.canonical.flow,
+            this.unitPolicy.output.flow,
+            'canonical->output flow',
+        );
     }
 
     getOutput()      { return io.getOutput(this); }