D
Don Y
Guest
On 8/14/2020 2:14 PM, Grant Taylor wrote:
\"I want the system to run for X minutes\" is a solution, not a problem
statement. All that follows that statement is *implementation*.
Before I design anything, I survey the likely users to see HOW they expect
a device to \"solve their problem(s)\" -- in this case, keeping the interior
space at a comfortable temperature with minimal intervention. For the
thermostat, that effort was over 100 \"consumer interviews\" -- not
\"paper surveys\" (because people don\'t seem to actively consider what
they are \"saying\").
In each case, I asked folks how they used their current thermostat, what
capabilities it presented, the problems it solved -- and the problems
it didn\'t solve or actually *introduced* (e.g., having to \"program\"
a thermostat is a problem that doesn\'t exist with a non-programmable
thermostat). I asked them how happy they were with the thermostat\'s
performance (letting THEM define performance however they saw fit).
I asked them what goal they had in purchasing that thermostat (better
plant control, energy efficiency/cost savings, \"tech appeal\", ease
of use, etc.) and how it had met/failed-to-meet that goal.
\"Sometimes, when I come into the house, I turn up the thermostat a
degree or two?\" (which is the only way they can cause the plant to fire)
\"Why?\"
\"To get the chill out of the air\"
I.e., they don\'t want the house to STAY \"a degree or two warmer\"; they
just want a temporary injection of heat. I noticed that this was
only the case with GFA plants; oil-fired hot water has so much lag
in it that there is no immediate sense of warmth -- your body acclimates
to the new indoor temperature faster than the environment can be
notably changed. By contrast, standing beside an HVAC register in a GFA
home it\'s obvious that hot air is flowing.
[I leverage that to provide \"max cool\" when occupants are looking for
a noticeable cooldown -- instead of letting the blower run at a slower
rate]
Then, grilled them as to why they hadn\'t purchased a Thermostat5000
or HeatNCool900 or... -- which seemed to also address their needs,
possibly better. Perhaps they were unaware of the product offering?
Or, intimidated by the UI? Or, the price tag and payback period?
Or, intimidated by the installation (do I have to HIRE an electrician)?
*Only* then, set out to figure out how to provide the desired functionality
and price point they seemed to endorse while avoiding the issues that
made them reluctant to adopt some other, existing \"solution\".
No, I see you sold yourself short in accepting a SOLUTION that popped into
your head instead of exploring what you REALLY wanted to do (\"get the
chill out of the air\"). You subconsciously replaced your real goal with
an artificial goal and then rationalized IT\'S solution as being the
desired solution.
What do you expect to get from your plant from X minutes of runtime?
Other than hearing the blower motor run for X minutes (if that\'s
all you wanted, then just run the FAN for X minutes and RATONALIZE
that you\'ve met your -- now doubly revised --goal)? Would you
accept a thermostat that operated as:
while (FOREVER) {
if (temperature < setpoint) {
run_furnace(X_minutes) // blocks!
}
}
What sort of performance would you expect from it? How would you
know to tweek X for tomorrow\'s conditions?
We have thermostats that control our evaporative coolers, here.
They are largely temperature driven. But, all suffer from a
fatal flaw: without knowledge of the exterior conditions,
they can make the interior WORSE than it would otherwise have
been if they\'d just left the cooler OFF:
\"Gee, temperature is still rising! Better keep the cooler
running on high...\"
[Of course it is rising! The current dewpoint is such that adding
moisture to the air will only cause the REPLACED interior air to
more quickly approach the temperature of the exterior air! E.g.,
if it\'s 100+ outdoors -- even if very dry -- and currently 70 inside,
there\'s almost no case where turning the cooler on will make you more
comfortable.]
They \"solved\" the wrong problem. But, \"it was easy\" -- use an
existing solution that they could con themselves into thinking was
correct (as long as you don\'t think too hard on it)!
[N.B. This remains the case, today. Because it has trained *users* to
compensate for its inadequacies. Like charging systems on electric
wheelchairs...]
\"I want the system to run for X minutes\" is a solution, not a problem
statement. All that follows that statement is *implementation*.
Before I design anything, I survey the likely users to see HOW they expect
a device to \"solve their problem(s)\" -- in this case, keeping the interior
space at a comfortable temperature with minimal intervention. For the
thermostat, that effort was over 100 \"consumer interviews\" -- not
\"paper surveys\" (because people don\'t seem to actively consider what
they are \"saying\").
In each case, I asked folks how they used their current thermostat, what
capabilities it presented, the problems it solved -- and the problems
it didn\'t solve or actually *introduced* (e.g., having to \"program\"
a thermostat is a problem that doesn\'t exist with a non-programmable
thermostat). I asked them how happy they were with the thermostat\'s
performance (letting THEM define performance however they saw fit).
I asked them what goal they had in purchasing that thermostat (better
plant control, energy efficiency/cost savings, \"tech appeal\", ease
of use, etc.) and how it had met/failed-to-meet that goal.
\"Sometimes, when I come into the house, I turn up the thermostat a
degree or two?\" (which is the only way they can cause the plant to fire)
\"Why?\"
\"To get the chill out of the air\"
I.e., they don\'t want the house to STAY \"a degree or two warmer\"; they
just want a temporary injection of heat. I noticed that this was
only the case with GFA plants; oil-fired hot water has so much lag
in it that there is no immediate sense of warmth -- your body acclimates
to the new indoor temperature faster than the environment can be
notably changed. By contrast, standing beside an HVAC register in a GFA
home it\'s obvious that hot air is flowing.
[I leverage that to provide \"max cool\" when occupants are looking for
a noticeable cooldown -- instead of letting the blower run at a slower
rate]
Then, grilled them as to why they hadn\'t purchased a Thermostat5000
or HeatNCool900 or... -- which seemed to also address their needs,
possibly better. Perhaps they were unaware of the product offering?
Or, intimidated by the UI? Or, the price tag and payback period?
Or, intimidated by the installation (do I have to HIRE an electrician)?
*Only* then, set out to figure out how to provide the desired functionality
and price point they seemed to endorse while avoiding the issues that
made them reluctant to adopt some other, existing \"solution\".
No, I see you sold yourself short in accepting a SOLUTION that popped into
your head instead of exploring what you REALLY wanted to do (\"get the
chill out of the air\"). You subconsciously replaced your real goal with
an artificial goal and then rationalized IT\'S solution as being the
desired solution.
What do you expect to get from your plant from X minutes of runtime?
Other than hearing the blower motor run for X minutes (if that\'s
all you wanted, then just run the FAN for X minutes and RATONALIZE
that you\'ve met your -- now doubly revised --goal)? Would you
accept a thermostat that operated as:
while (FOREVER) {
if (temperature < setpoint) {
run_furnace(X_minutes) // blocks!
}
}
What sort of performance would you expect from it? How would you
know to tweek X for tomorrow\'s conditions?
We have thermostats that control our evaporative coolers, here.
They are largely temperature driven. But, all suffer from a
fatal flaw: without knowledge of the exterior conditions,
they can make the interior WORSE than it would otherwise have
been if they\'d just left the cooler OFF:
\"Gee, temperature is still rising! Better keep the cooler
running on high...\"
[Of course it is rising! The current dewpoint is such that adding
moisture to the air will only cause the REPLACED interior air to
more quickly approach the temperature of the exterior air! E.g.,
if it\'s 100+ outdoors -- even if very dry -- and currently 70 inside,
there\'s almost no case where turning the cooler on will make you more
comfortable.]
They \"solved\" the wrong problem. But, \"it was easy\" -- use an
existing solution that they could con themselves into thinking was
correct (as long as you don\'t think too hard on it)!
[N.B. This remains the case, today. Because it has trained *users* to
compensate for its inadequacies. Like charging systems on electric
wheelchairs...]