Anyone take the CRD recently? Trying to figure out how deep the heat pump sizing content goes

I passed on my second attempt. First time I underestimated the regulatory and installation standards sections. They showed up more than I expected and I hadn't given them enough time.

The exam does allow a reference sheet for certain calculations, but you need to know which formula applies and when. Don't rely on it as a crutch — you have to set up the problem correctly first.

Conceptual questions outnumbered pure calculation ones in my exam. But when calculations appeared they required real setup work, not just plugging in numbers. Practice the full problem-solving process.

Bore field sizing was the most technical portion of what I saw. Understand EWT, LWT, and the relationship between loop length and soil conductivity — those came up repeatedly.

I passed the CRD about eight months ago while working full-time doing commercial HVAC. Honestly the heat pump sizing content wasn't as brutal as I expected. You'll need to know Manual J and Manual S pretty solid, and there are definitely questions that go into load calculations and equipment selection ratios, but it's not like they're trying to trick you with obscure stuff. The theory layer is real but it's grounded in stuff you'd actually use on a job.

For studying I basically did an hour or two after the kids went to bed, maybe three nights a week. Took me about four months to feel ready. If you've got 14 years in the field a lot of it's going to click fast, you're mostly just learning the language the exam uses for things you already know how to do. The geothermal-specific stuff is worth paying extra attention to since it shows up more than you'd think.

I took it about four months ago coming from a similar background -- commercial HVAC, not geothermal, but same idea where I thought field experience would carry me. The heat pump sizing stuff is definitely there and it goes deeper than just pulling numbers off a table. What tripped me up wasn't the calculations themselves, it was understanding why certain approaches are wrong, not just which answer is right. There's a difference between knowing the correct sizing methodology and actually understanding why oversizing a ground loop causes the specific problems it causes.

Honestly that mindset shift is what got me through it. I started reviewing wrong answers and working backwards to figure out the reasoning, and it clicked way better than just drilling the right ones. If you've got 14 years in HVAC you're not starting from zero, but don't assume the theory parts will be obvious either. Some of it was stuff I'd been doing correctly for years without ever having to articulate the underlying principle.

I'm in a similar boat — 12 years in the field and just passed the CRD about three months ago while working full time. The heat pump sizing content is deeper than I expected, but it's manageable. It's not just rule-of-thumb stuff; they actually want you to understand load calculation methodology and why you're sizing the way you are, especially for geothermal where the ground loop interaction matters. I studied in 20-30 minute chunks most evenings and a longer session on weekends. Honestly that was enough.

For the geothermal side specifically, I'd work through the crd/questions/geothermal system design principles 2 practice questions because they cover the theory angle pretty well. With your field experience you'll find a lot of it clicks fast — the tricky part wasn't the concepts themselves, it was the exam's specific wording and how they frame scenario questions. Don't overthink the prep. You've already got the hardest part covered.

Honestly, I almost bailed on the CRD about two weeks before my test date. I'd been doing geothermal for six years and figured my field experience would carry me, but the heat pump sizing questions hit different than I expected. It's not just "size the loop field and move on" -- they want you to know the why behind your numbers. Manual J load calcs, EWT ranges, COP at various conditions. If you've been doing this by feel and rule of thumb, you'll need to actually sit down with the theory for a bit.

That said, you're not walking in blind with 14 years of HVAC behind you. The concepts aren't foreign, they just want you to be able to articulate them. I spent the last week drilling the sizing formulas and it clicked fast because I already understood what was happening in the field. Keep going. It's worth it and you're closer than you think.

Failed it my first attempt, so I can tell you from experience: it's way more theory-heavy than you'd expect coming from the field. I've got years of hands-on installs under my belt and I thought that would carry me, but it didn't. The heat pump sizing questions weren't just "pick the right tonnage" -- they wanted me to know the math behind it, load calc methodology, soil conductivity stuff I'd never had to think about on a job site. Second time around I spent a solid two weeks on the conceptual side, especially geothermal-specific design principles. The practice questions at crd/questions/geothermal system design principles 2 were actually really close to what showed up on the real exam.

The good news is if you understand the "why" behind your installs, it clicks faster than you'd think. Wasn't easy, but I passed second attempt with a decent margin. Just don't go in assuming field experience is enough -- it isn't.